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@title{WORKS}{Shared Works Controls} The following topics are for GUI controls, shared between some or all Works programs (ImageWorks, GCPWorks, ...). See Also: {IWORKS}ImageWorks, GCPWorks 1 Data File Manipulation All Works programs share a common interface for creating, selecting, reading, and writing image and auxiliary information to disk files. The Works data file manipulation capabilities include reading and writing image data, graphic data, vector data, LUTs, and PCTs to a variety of data file formats, including PCIDSK, TIFF, X Window Dump, Intergraph COT, ARC/Info Generate, Erdas .LAN and .GIS, and Sun Raster files. 2 File Selection Panel The file selection panel is used to select database files for a variety of purposes. It typically can be used to select any supported database type, including PCIDSK, TIFF, X Window Dump, Sun Raster, Raw Imagery, Intergraph Continuous Tone (COT), Erdas (.lan or .gis), and ARC/INFO Generate vectors. The file selection panel can be invoked from the ``Open'' entry of the ``File'' pulldown menu. It is also popped up any time a Load or Save operation is requested, when there is not yet a selected file. If the selected file does not exist, the user will be asked if a new file should be created. If the file is of no recognized format, the user will be asked whether to describe the file as a raw imagery file via the Raw Imagery File Definition panel, or to cancel the selection. The following topics describe details of the support for the various file formats. See Also: {..|raw imag}Defining Raw Files, {..|}GDB File Formats 2 GDB File Formats PCI's Works programs use a Generic DataBase library (GDB) to access image, and auxiliary information from data files. This allows different file types to be used interchangeably where it makes sense for the file type. To access a file, it is normally just necessary to select it with the File Selection Panel, regardless of the format. The GDB library will recognize the file if it is a supported format. To create new files of a supported format, use the File Creation Panel; however, note that some file formats can be read, but not written or created. See Also: {GDB|}Supported File Formats, {..|}File Selection Panel, {..|}File Creation 2 Raw Imagery File Definition Panel When an unrecognizable file is selected using the File Selection Panel, the user is given the option of defining it as a Raw Imagery File. This panel is used to define the format of the raw imagery file. The ``Cancel'' button can be used if the user decides not to define the selected file as a raw imagery file. Following is a description of fields on the panel: 3 Header Bytes This field specifies how many bytes at the beginning of the file represent header information to be ignored. The default value is zero, indicating that the imagery data starts right at the beginning of the file. 3 Image Size These two fields define the X (Pixel) and Y (Line) size of the image in the imagery file. These should be the full size of the image in the file, even if the user only wishes to load a subwindow of the whole file. 3 Number of Channels Indicates the number of channels or planes of image data stored in the file. This value defaults to 1. 3 Data Interleaving Indicates how multiple channels of image data are interleaved. This field is not applicable for 1 channel image files. Possible choices are as follows: - PIXEL: the channels are pixel interleaved. For instance, for a three channel file, the values in the file would be 123123123..., with the channel values for a given pixel located together. - LINE: The channels are line interleaved. The data for line 1 of the first channel occurs first, followed by the data for line 1 of the second channel and line 1 of the third channel. Next is line 2 of the first channel, etc. For instance, for a three channel file, the values in the file would be (line 1)111...222...333(line 2)111...222...333... - BAND: The channels are band sequential. All the data for the entire first channel would be first, followed by all the data for the second channel, etc. 3 Data Type This field is used to define the size and meaning of the data read for each pixel. - 8 bit: The data for each channel of each pixel are 8 bit, unsigned. Values range from 0 to 255. - 16 bit Unsigned: The data for each channel of each pixel are 16 bit, unsigned. Values range from 0 to 65535, and are two bytes each. - 16 bit Signed: The data for each channel of each pixel are 16 bit, signed. Values range from -32768 to 32767, and are two bytes each. - 32 bit Real: The data for each channel of each pixel are 32 bit IEEE floating point numbers. Each value is 4 bytes long. 3 Saving Raw Configuration When the ``Accept'' button in in the Raw Imagery Definition panel is pressed the user is asked if they would like to save their raw definition of the image file. If they answer yes a new header file with the extension .aux and the same basename as the file being defined will be created. This file will contain information on the layout of the imagery as provided by the user. Whenever the image file is selected in the future by a program with Generic DataBase (GDB) support (such as ImageWorks) the file will be automatically recognised without being redefined. The following is an example of the file produced for a simple 1000x1000 eight bit single channel image. AuxiliaryTarget: rawimage.bil RawDefinition: 1000 1000 1 ChanDefinition-1: 8U 0 1 1000 Swapped If the .aux file cannot be written due to the permissions on the directory in which the target file is stored there will be no error message generated; however, the user will have to define the file each time it is used. Also note that once the .aux file is created the user will not get an opportunity to define the raw file again until the .aux file is deleted. Therefore when experimenting with possible raw file definitions it is best not to create an .aux file. See Also: GDB 2 File Creation The New File Type selection panel allows the user to select the type of database file to create. If the user does not want to create a file, the Cancel button should be pressed. This panel is invoked from the File Selection panel by entering the name of a file that does not exist, or from the main menu bar by selecting the ``New'' entry from the ``File'' pulldown menu. To create a new database file, select the type of file desired and hit OK. A panel specific to the desired file type will be popped up, allowing for the setting of specific creation information. Once the file is created, it will become the currently selected file and data may be saved in it. The action of creating a file does not write any data to the file, this must be done explicitly using the various save panels. Newly created files are not necessarily written completely to disk till the program is exited, or another file is selected. The ARC/Info Generate, AutoCAD DXF, DLG-3 and GRASS Vector file types require no additional information and will be created immediately after the OK button is selected. 3 PCIDSK File Creation The PCIDSK File Creation panel allows the user to enter the desired filename, description, size, channel data type, and georeferencing information for a new PCIDSK database file. In the ``Name and Identification'' Area of the panel the Facility and Description fields contain optional comment information to be stored in the file header. The ``Geo-Referencing Information'' area of the panel allows the user to input the size of the file in pixels and lines, together with the pixel size. The option menu indicates the manner in which the file is created regarding the variation of the input parameters. If ``Use pixels/lines and bounds'' is selected then ``pixel size'' will be varied so that a file is created with the requested pixels, lines, and bounds. Similarly, the bounds will be varied if ``Use pixel/lines and resolution'' is selected. Finally the pixel and lines will be varied if ``Use bounds and resolution'' is selected. The georeferencing system and bounds of the new file are specified with the GeoEdit control which is described in more detail in the GeoEdit topic. The user will be prompted for confirmation before the file is created. See Also: {GDB|Supported|PCIDSK}PCIDSK Details, GeoEdit 3 TIFF File Creation The TIFF File Creation panel allows the user to enter the desired file name, size, and configuration. A TIFF file may be in one of three configurations. It may be an RGB file (three channels, TIFF R), a single eight bit channel with an optional Pseudocolour Table (TIFF G or P) or a single bitmap (TIFF B). Georeferencing information for the TIFF file may be specified using the GeoEdit control. Note that the georeferencing will be placed in an additional text file (with the extension .aux) and will not be recognised by any package except EASI/PACE. After the file name, configuration, and database size have been set, the ``Create'' button will proceed to create the requested file. It is not possible to create compressed TIFF files. The PACE task FEXPORT must be used for that. See Also: FEXPORT, {GDB|Supported|TIFF}TIFF Details, GeoEdit 3 Laser-Scan File Creation The Laser-Scan File Creation panel allows the user to enter the desired file name, size, and configuration. A Laser-Scan file may be in one of the five supported types. It can be an uncompressed greyscale, compressed pseudo-coloured, uncompressed RGB, uncompressed bitmap and uncompressed pseudo-coloured. It is not possible to create the type 1 and 6 (compressed bitmap) formats of Laser-Scan files. Note that there is only one opportunity to save to compressed Laser-Scan files using the ``Save Imagery'' panel. See Also: FEXPORT, {GDB|Supported|Laser}Laser-Scan Details 3 X Window Dump File Creation The X Window Dump File Creation panel allows the user to enter the desired file name, size, and configuration. An X Window dump file may be in one of four configurations. It may be an RGB file (three channel) with or without LUTs, or a single eight bit channel with an optional Pseudocolour Table. The RGB files without LUTs, and eight bit files with PCTs are most likely to be supported by other software that reads and writes X Window Dump files. After the file name, configuration, and database size have been set, the ``Create'' button will proceed to create the requested file. It will then become the currently selected file. The ``Cancel'' button may be used to abort file creation; control will be returned to the file selection panel. See Also: FEXPORT, {GDB|Supported|X Win}X Window Dump Details 3 Sun Raster File Creation The Sun Raster File Creation panel allows the user to enter the desired file name, size, and configuration. An Sun Raster file may be have either one, or three image planes. After the file name, configuration, and database size have been set, the ``Create'' button will proceed to create the requested file. It will then become the currently selected file. The ``Cancel'' button may be used to abort file creation; control will be returned to the file selection panel. If the created file has one image plane, it will also have an associated PCT. If an RGB file is created each band will have an associated LUT, though many packages may ignore it. See Also: FEXPORT, {GDB|Supported|Sun}Sun Raster Details 3 Erdas .LAN and .GIS File Creation The Erdas File Creation panel allows the creation of 8 bit or 16 bit Erdas .LAN or .GIS files with a requested file name, size, and number of channels. When .LAN files are created, only one channel should be selected. Note that it is not possible to create Erdas 4 bit files, and that all files created are the Erdas 7.4 format. The new version 8.0 format is not supported. The georeferencing system, and bounds for the output file can be set with the GeoEdit control. Note that of the visible georeferencing systems, only Long/Lat, and UTM will be accurately exported in the Erdas file. After the file name, georeferencing, data type, database size, and number of channels have been set, the ``Create'' may be used to create the requested file. It will then become the currently selected file. The ``Cancel'' button may be used to abort file creation. See Also: FEXPORT, {GDB|Supported|Erdas}Erdas Details, GeoEdit 3 GRASS Cell File Creation The Grass Cell File Creation panel allows the creation of a GRASS Cell file with a requested file name, size, format and Georeferencing information. After the file name, database size, and format have been specified with the appropriate georeferencing information, the ``Create'' button can be used to create the file. Note that only UTM georeferencing is reliably supported when creating GRASS raster layers. There are two ways to specify where the new cell file should be created. One is to specify the entire path to the cell header in the ``cellhd'' directory. The other is to supply on the layer name, but this requires that a valid .grassrc be supplied. In this case the cell will be placed in the current MAPSET from the .grassrc file. It is also imperative that the user have already created the ``cell'' and ``cellhd'' directories, and that they be writable before trying to create a new cell. See Also: {GDB|Supported|GRASS}GRASS Details, GeoEdit 2 Loading Image Data The Load Imagery Panel allows the user to select one or more channels to be loaded from the currently selected file, to selected image planes in memory. A subwindow of data may also be selected. The Database Channels and Database Window Selection areas of the panel are described in the following subtopics. When the desired channel load mapping and input window have been chosen, the ``Load'' button will load the image channels but leave the load panel visible. The ``Load And Close'' button will load the requested image channels, and pop the panel down. The ``New File'' button is used to select a new database from which to load. 3 Database Channels The ``Database Channels'' section of the Load Imagery panel allows the user to select the image channels to be loaded by clicking on them. The database channels are found in a scrollable list with a description of the source data type, and a descriptor from the file. Beneath the scrollable list is a series of channel mapping pairs. On the left of each pair is the number of an image plane in memory, and on the right is a blank field into which a database channel number can be placed. When one of the right side text fields contains a number, it indicates that the corresponding image plane in memory will be loaded from the database channel. For example, the following mapping would indicate that channels 1 and 2 from the database will be loaded into image planes 2 and 3 in memory. 1 : _ 2 : 1 3 : 2 Beneath the channel mapping pairs, are Clear and Default action buttons. Pressing the Clear button erases the current channel map, while pressing the Default button establishes a default channel mapping. 3 Database Window Selection The Database Window Selection is found beneath the Database Channels section. On the left of this area is a box containing a subwindow box. The outline box is a graphic representation of the selected database, while the subwindow box is a graphic representation of the subwindow of data to be loaded from the selected database. By default, the loaded subwindow is the whole database. The size, shape, and placement of the subwindow may be manipulated with the mouse in a manner very similar to window resizing. A textual version of the database subwindow to be loaded is located to the right of the graphical view. It is shown in the usual EASI/PACE form: X Offset, Y Offset, X Size, Y Size This text field may be edited to modify the loaded subwindow. Three action buttons are also available. The Overview button resets the subwindow to be the whole database area. The Full Res (Full Resolution) button forces the window size to be no larger than the size of the in-memory image planes. This ensures that image data is being loaded at full resolution. The 1:1 Aspect ratio button clips the image window to make the database loading subwindow the same shape as the in-memory image planes. This ensures that at a zoom level of 1 or more, the viewed data will have a 1:1 aspect ratio relative to the database. This aspect ratio correction does not account for distortion due to pixel size when displayed on the monitor. If the ``Preview'' push button on the titlebar is depressed, the first one or three channels of the database file will be displayed in the subwindow. 2 Loading Graphic Data The Load Graphics panel allows the user to select one or more channels to be loaded from the currently selected file, to selected graphic planes in memory. A subwindow of data may also be selected. The Database Bitmap Segments and Database Window Selection areas of the panel are described in the following subtopics. When the desired bitmap load mapping and input window have been chosen, the ``Load'' button will load the bitmap segments, but leave the load panel visible. The ``Load And Close'' button will load the requested bitmaps, and pop the panel down. The ``New File'' action button is used to select a new database from which to load. 3 Database Bitmap Segments The ``Database Bitmap Segments'' section of the Graphic Load panel allows the user to select the bitmap segments to be loaded by clicking on them. The database bitmaps are found in a scrollable list with a descriptor. Beneath the scrollable list is a series of bitmap mapping pairs. On the left of each pair is the number of a graphic plane in memory, and on the right is a blank field into which a database segment number can be placed. When one of the right side text fields contains a number, it indicates that the corresponding graphic plane in memory will be loaded from the database bitmap segment. For example, the following mapping would indicate that segments 3 and 4 from the database will be loaded into graphic planes 2 and 3 in memory. 1 : _ 2 : 3 3 : 4 Beneath the segment mapping pairs, are Clear and Default action buttons. Pressing the ``Clear'' button erases the current segment map, while pressing the Default button establishes a default segment-to-graphic mapping. 3 Database Window Selection The Database Window Selection area is found beneath the Database Bitmap Segments section. On the left of this area is a box containing a subwindow box. The outline box is a graphic representation of the selected database, while the subwindow box is a graphic representation of the subwindow of data to be loaded from the selected database. By default, the loaded subwindow is the whole database. The size, shape, and placement of the subwindow may be manipulated with the mouse in a manner very similar to window resizing. A textual version of the database subwindow to be loaded is located to the right of the graphical view. It is shown in the usual EASI/PACE form: X Offset, Y Offset, X Size, Y Size This text field may be edited to modify the loaded subwindow. Three action buttons are also available. The ``Overview'' button resets the subwindow to be the whole database area. The ``Full Res'' (Full Resolution) button forces the window size to be no larger than the size of the in-memory graphic planes. This ensures that graphic data is being loaded at full resolution. The 1:1 Aspect ratio button clips the load window to make the database loading subwindow the same shape as the in-memory graphic planes. This ensures that at a zoom level of 1 or more, the viewed data will have a 1:1 aspect ratio relative to the database. This aspect ratio correction does not account for distortion due to pixel size when displayed on the monitor. Pressing the ``Preview'' push button from the titlebar will display only imagery information off the database. There will be no bitmap displayed in the subwindow. 2 Loading Vector Data The Load Vectors panel allows the user to load new vector layers one at a time from a database file. Each load operation creates one new vector layer in memory. Each newly loaded vector layer is placed at the highest level of priority relative to the other vector layers. To load a vector layer, select the layer from the scrollable list of ``Database Vector Segments''. The "Load" action button will load the vector segment, but leave the load panel visible. The ``Load And Close'' button will load the vector segment, and pop the panel down. The ``New File'' action button is used to select a new database from which to load. Vector layers are loaded into memory, and so for very large vector layers there may not be enough memory to load the vectors. If this occurs it is possible to use the CompactVectors preference to reduce the amount of memory used by a vector layer. See Also: {IWORKS|Pref|}Compact Vectors 2 Loading LUTs The Load LUT (Lookup Table) panel allows the user to select one or more LUTs to be loaded from the currently selected file and to be associated with selected image planes. The ``Database LUT Segments'' section of the Load LUT panel allows the user to select the LUT segments to be loaded by clicking on them. The database LUTs are found in a scrollable list with a descriptor. Beneath the scrollable list is a series of LUT mapping pairs. On the left of each pair is the number of an image plane in memory, and on the right is a blank field into which a database LUT segment number can be placed. When one of the right side text fields contains a number, it indicates that the corresponding image plane in memory will be associated with the LUT loaded from the LUT segment. For example, the following mapping would indicate that LUT segments 3 and 4 from the database will be loaded and associated with image planes 2 and 3 in memory. 1 : _ 2 : 3 3 : 4 Beneath the segment mapping pairs are Clear and Default action buttons. Pressing the ``Clear'' button erases the current segment map, while pressing the Default button establishes a default segment to image plane mapping. When the desired LUT segment to image plane load mapping has been established, the ``Load'' button will load the LUT segments, but leave the load panel visible. The ``Load And Close'' button will load the requested LUTs, and pop the panel down. The ``New File'' action button is used to select a new database from which to load. 2 Loading PCT Data The PCT (Pseudo Colour Table) loading panel allows the user to load a PCT segment from a database, to replace the PCT currently in memory. To load a PCT segment, select the layer from the scrollable list of ``Database PCT Segments''. The ``Load'' action button will load the PCT segment, but leave the load panel visible. The ``Load And Close'' button will load the PCT segment, and pop the panel down. The ``New File'' action button is used to select a new database from which to load. Note that in ImageWorks loading a PCT segment does not place the application in Pseudo-Colour display mode. This must still be done on the Control Panel. See Also: {IWORKS|Control Pan}ImageWorks Control Panel 2 Loading GCP The GCP (Ground Control Point) loading panel allows the user to load a GCP segment from a database, to replace the set of GCPs currently in memory. To load a GCP segment, select the layer from the scrollable list of ``Database GCP Segments''. The ``Load'' action button will load the GCP segment, but leave the load panel visible. The ``Load And Close'' button will load the GCP segment, and pop the panel down. The ``New File'' action button is used to select a new database from which to load GCPs. 2 Saving Image Data The image saving panel allows the user to save one image plane from in-memory to an image channel on a database file. While the entire ImageWorks data area is always saved, the user can specify a subwindow of the database channel to which the image plane data is saved. The image plane data is decimated to fit the specified subwindow. The save panel is divided into four subareas, which are described in the following subtopics. When the desired channel mapping and output window have been chosen, the ``Save'' button will save the image plane, but leave the save panel visible. The ``Save And Close'' button will save the requested image plane, and pop the panel down. The ``New File'' action button is used to select a new database to which to save the image plane data. 3 Planes and Channels The ``Savable Image Planes'' section of the Image Save panel is used to select an in-memory image plane to save to the disk file. It is a scrollable list of image planes, and the selected image plane to be saved is highlighted. The ``Database Channels'' section of the Image Save panel is used to select a channel on the database file to which to save the in-memory image plane. It is a scrollable list of image channels, and the selected channel to which the image plane data will be saved will appear highlighted. It is necessary that both a savable image plane and a database channel be selected before imagery can be saved. 3 Database Window Selection The Database Window selection area is found beneath the Database Channels section. On the left of this area is a box containing a subwindow box. The outline box is a graphic representation of the selected database, while the subwindow box is a graphic representation of the database subwindow to which the image plane data will be saved. By default, the subwindow is the whole database. The size, shape, and placement of the subwindow may be manipulated with the mouse in a manner very similar to window resizing. A textual version of the database subwindow to which imagery will be saved is located to the right of the graphical view. It is shown in the usual EASI/PACE form: X Offset, Y Offset, X Size, Y Size This text field may be edited to modify the subwindow. Three action buttons are also available. The Overview button resets the subwindow to be the whole database area. The Full Res (Full Resolution) button forces the window size to be no larger than the size of the in-memory image plane. This ensures that image data is being saved at full resolution. The 1:1 Aspect ratio button clips the image window to make the database subwindow the same shape as the in-memory image plane. This ensures that the aspect ratio of the image data is preserved. 3 Channel Information The Channel Information area is used to modify the channel description to be saved with the image plane. The number of the currently selected image channel is shown beside the Number field. 2 Saving Graphic Data The Save Graphic panel allows the user to save one graphic plane from in-memory to a bitmap segment on a database file. While the entire ImageWorks graphic data area is always saved, the user can specify a subwindow of the database channel to which the graphic plane data is saved. The graphic plane data is decimated to fit the specified subwindow. The save panel is divided into four subareas, which are described in the following subtopics. When the desired graphic plane to bitmap segment mapping and output window have been chosen, the ``Save'' button will save the graphic plane but leave the save panel visible. The ``Save And Close'' button will save the requested graphic plane, and pop the panel down. The ``New File'' action button is used to select a new database to which to save the graphic plane. 3 Graphics Planes and Bitmaps The ``Savable Graphic Planes'' section of the Graphic Save panel is used to select an in-memory graphic plane to save to the disk file. There is a scrollable list of graphic planes, and the selected graphic plane to be saved is highlighted. The ``Database Bitmap Segments'' section of the Graphic Save panel is used to select a bitmap segment on the database file to which the graphic plane will be saved. It is a scrollable list of bitmap segments, and the selected bitmap segment to which the graphic plane will be saved will appear highlighted. If the database file, to which the graphic plane will be saved, is a PCIDSK file, it is not necessary to select a bitmap segment. If no target bitmap segment has been selected, or the ``Number'' field of the Segment Information area has been cleared, a new bitmap segment will be created. 3 Database Window Selection The Database Window Selection is found beneath the Database Bitmap Segments section. On the left of this area is a box containing a subwindow box. The outline box is a graphic representation of the selected database, while the subwindow box is a graphic representation of the database subwindow to which the graphic plane will be saved. By default, the subwindow is the whole database. The size, shape, and placement of the subwindow may be manipulated with the mouse in a manner very similar to window resizing. A textual version of the database subwindow to which the graphic plane will be saved is located to the right of the graphical view. It is shown in the usual EASI/PACE form: X Offset, Y Offset, X Size, Y Size This text field may be edited to modify the subwindow. Three action buttons are also available. The Overview button resets the subwindow to be the whole database area. The Full Res (Full Resolution) button forces the window size to be no larger than the size of the in-memory graphic plane. This ensures that image data is being saved at full resolution. The 1:1 Aspect ratio button clips the image window to make the database subwindow the same shape as the in-memory graphic plane. This ensures that the aspect ratio of the graphic data is preserved. 3 Segment Information The Segment Information area is used to modify the segment name and description, to be saved with the graphic plane. The number of the currently selected segment bitmap is shown beside the Number field. 2 Saving Vector Data The vector saving panel allows the user to save one vector layer from in-memory to a vector segment on a database file. The save panel is divided into three subareas, which are described in the following subtopics. When the desired vector layer to vector segment mapping has been chosen the ``Save'' button will save the vector layer but leave the save panel visible. The ``Save And Close'' button will save the requested vector layer, and pop the panel down. The ``New File'' action button is used to select a new database to which to save the vector data. 3 Vector Layers and Segments The ``Savable Vector Layers'' section of the Vector Save panel is used to select an in-memory vector layer to save to the disk file. It is a scrollable list of vector layers, and the selected vector layer to be saved is highlighted. The ``Database Vector Segments'' section of the Vector Save panel is used to select a vector segment on the database file to which to save the vector data. It is a scrollable list of vector segments, and the selected vector segment to which the vector data will be saved will appear highlighted. If the database file, to which the graphic plane will be saved, is a PCIDSK file, it is not necessary to select a vector segment. If no target bitmap segment has been selected, or the ``Number'' field of the Segment Information area has been cleared, a new vector segment will be created. 3 Segment Information The Segment Information area is used to modify the segment name and description, to be saved with the vector information. The number of the currently selected vector segment is shown beside the Number field. 2 Saving LUT Data The LUT (Lookup Table) saving panel allows the user to save one of the LUTs currently associated with an image plane in memory. The save panel is divided into three subareas, which are described in the following subtopics. When the desired image plane to LUT segment mapping has been chosen, the ``Save'' button will save the LUT but leave the save panel visible. The ``Save And Close'' button will save the requested LUT, and pop the panel down. The ``New File'' action button is used to select a new database to which to save the vector data. 3 Savable LUTs and LUT Segments The ``Savable LUTs'' section of the LUT Save panel is used to select an in-memory LUT to save to the disk file. It is a scrollable list of LUTs associated with image planes, and the selected LUT to be saved is highlighted. The ``Database LUT Segments'' section of the LUT Save panel is used to select an LUT segment on the database file to which to save the LUT. It is a scrollable list of LUT segments, and the selected segment to which the LUT will be saved will appear highlighted. If the disk file, to which the LUT will be saved, is a PCIDSK file, it is not necessary to select an LUT. If no target LUT segment has been selected, or the ``Number'' field of the Segment Information area has been cleared, a new LUT segment will be created. 3 Segment Information The Segment Information area is used to modify the segment name and description, to be saved with the vector information. The number of the currently selected vector segment is shown beside the Number field. 2 Saving PCT Data The Save PCT Panel is used to save the single in-memory PCT (Pseudo-Colour Table) to a database file. The ``Database PCT Segments'' section of the PCT Save panel is used to select a PCT segment on the database file to which to save the PCT. It is a scrollable list of PCT segments, and the PCT selected segment to which the PCT will be saved will appear highlighted. When saving to PCIDSK database files it is not necessary to select a PCT segment. If none are selected, or if the ``Number'' field is cleared, a new PCT segment will be created on the database. 2 Saving GCPs The Save GCP Panel is used to save a set of GCPs (Ground Control Points) to a database file. The ``Database GCP Segments'' section of the GCP Save panel is used to select a GCP segment on the database file to which to save the GCP. It is a scrollable list of GCP segments, and the GCP selected segment to which the GCP will be saved will appear highlighted. When saving to PCIDSK database files it is not necessary to select a GCP segment. If none are selected, or if the ``Number'' field is cleared, a new GCP segment will be created on the database. 2 Read GCP Text File @keywords{Text file GCPs Read Ground Control} The ``Read GCP Text File'' panel is used to read GCPs from a text file with a user described format. It can be launched from the File menu of the GCP Selection and Editing panel of GCPWorks, or the primary File menu of OrthoEngine. The general idea of the panel is for the user to select a text file containing GCPs, enter a format string to parse the file with, and after using the format string to examine the extract GCPs to see if they are what was expected. The user can also set the projection of the GCPs. At the top of the panel the user can type in the name of the text file to work with, or launch a file selector by pressing the Select button. As soon as a file is successfully selected the contents of the file will be displayed in the list box titled Example Lines from GCP File for user review. Once a file has been selected the user should enter a format string in the Format Description field which describes how to parse the gcp file. Further information about format strings follows in a subtopic. The format string may be entered directly in the text field, or selected from the list of example format strings to it's right. Once a format string has been entered or selected it is necessary to press the Use Format button in order to perform a test parsing. The contents of of the GCP text file will be parsed with the format string, and the exacted GCPs will be displayed in the GCPs Extracted from Text File list box for review. The extracted GCPs will always display the all the GCP fields, even those where were not extracted from the source file. They are displayed with the GCP Id, image pixel, image line, georef easting, georef northing and elevation. The View/Edit Projections button can be used to define the georeferencing system of the GCPs being read so that the application can reproject them if necessary. 3 Formats The format string, or ``Format Description'' field on the Read and Write GCP Text File panels is used to enter a symbolic representation of the GCP file format. Each character in the format string represents a field in the text file to be read or written. There are current seven different field types supported, of which X and Y are required. - I: GCP Identifier - In GCPWorks this must be numeric, while in OrthoEngine this is alphanumeric. - X: The geocoded X coordinate. - Y: The geocoded Y coordinate. - P: The pixel (left-right) location of the GCP on the uncorrected image file. The center of the top left pixel would be pixel 0.5. - L: The scanline (top-bottom) location of the GCP on the uncorrected image file. The center of the top left pixel would be pixel 0.5. - E: The elevation. - D: A dummy field value we need to skip, but aren't otherwise interested in. Mainly useful when reading GCP files. The input lines from the text file are split into fields based on white space (spaces and tabs) as well as commas. If a line contains text in double quotes the text in double quotes will be considered all part of one field. Each GCP must appear on it's own line in the text file. Examples: 1,17000, 12000 -> 3 fields: "1", "17000", "12000" 1 17000 12000 -> 3 fields: "1", "17000", "12000" Pig Farm 17000 12000 -> 4 fields: "Pig", "Farm", "17000", "12000" 1 17000m 12000m -> 3 fields: "1", "17000m", "12000m" 1 17000 m 12000 m -> 5 fields: "1", "17000", "m", "12000", "m" "Pig Farm" 17000 12000 -> 3 fields: "Pig Farm", "17000", "12000" The numeric values can be integral (123), decimal (123.456), or exponential (1.234+E05). Numeric fields may have alphabetic text at the end of the field and it will be ignored. Lat/long values must appear in decimal degrees (123.5) rather than DMS form (123 30 00). Text lines that can't be parsed according to the entered format string will be ignored. For a line to match a format string it must have exactly the right number of fields for the format string, no more and no less. The number of ignored lines will be reported if it is more than zero. Example lines: 1 76 90 430915.00000 3731875.00000 2 140 117 432995.00000 3730885.00000 In the above example lines there are five fields. The first is a GCP identification number, the second is the pixel offset in the image, the third is the line offset, the forth is the UTM easting value and the last is the UTM northing value. For this we would use a format string of "IPLXY". Example lines: 1 M 76 90 71.753326N 16.189745W 117.3 2 H 140 117 71.751354N 16.188130W 140.9 In the above example lines we have seven fields. The second field is a confidence value, but we can't use this so we use a field value of ``D'' to indicate a dummy field at this location. The fifth field is a latitude expressed in decimal degrees, followed by a longitude in decimal degrees. The last item on the line is an elevation in meters. We use a format string of "IDPLYXE". Because the latitude (north/south) value comes before the longitude (east/west) we have to put YX instead of the more common XY. The `N' and `W' indicators after the lat/long values are ignored so we will have to go in later and add a negative sign to for all the longitudes to express the fact that they are west (negative). Example lines: RH00107 4.309150+E05 3.731875+E06 RH00108 4.329950+E05 3.730885+E06 In the above example lines an alpha numeric identifier is given with the easting and northing values in exponential format. In OrthoEngine we would use a format string of "IXY" for this, while in GCPWorks we would have to use a format string of "DXY" as OrthoEngine supports alphanumeric GCP Ids and GCPWorks does not. The user will have to interactively set the image location for these GCPs before they will actually be useful, and without meaningful GCP Id's in GCPWorks this will be difficult. 2 Write GCP Text File @keywords{Text file GCPs Write Ground Control} The ``Write GCP Text File'' panel is used to write GCPs to a text file in a user described format. It can be launched from the File menu of the GCP Selection and Editing panel of GCPWorks, or the primary File menu of OrthoEngine. The general idea of the panel is for the user to select a text file to write the GCPs to, and enter a format string indicating what fields should be put in the file. The output file contents are displayed to the user so they can establish if the format is as required. At the top of the panel the user can type in the name of the text file to work with, or launch a file selector by pressing the Select button. Once a file has been selected the user should enter a format string in the Format Description field which describes how to write the GCP file. Further information about format strings can be found in the Read GCP Text File topic. The format string may be entered directly in the text field, or selected from the list of example format strings to it's right. Once a format string has been entered or selected it is necessary to press the Use Format button in order to perform display what the text file will look like. This will be placed in the Output Text File list. Note that there is no option to set the projection of GCPs being written to a text file. They will always be written the projection being used by the application. See Also: {..|Read GCP Text File|}Formats 1 Saving Reports This panel is used for saving text reports to a text file. The text file to place the report in can be selected by entering the name in the provided text field, or by using the system file selector invoked with the Select button. To append the report to the named file press the Append button. To overwrite the existing report file press the Overwrite button. The Cancel button can be used to close the panel, without writing the report to the file. 1 Georeferencing Editor @index{Georeferencing Editor}{Projections!Georeferencing Editor} @keyword{GeoEdit Georeferencing Projections Geocoding} @alias{GeoEdit} The Georeferencing Editor (or GeoEdit) is a standard Works control for viewing and editing the georeferencing system, bounds and projection definition for the data layers. The GeoEdit object comes in two forms. The first is the minimal form and contains only the controls for setting the georeferencing system (e.g. UTM, Long/Lat), while the second form also includes the georeferenced bounds of the region being described. Both forms allow viewing and editing the projection definition. There are also two modes for the GeoEdit control. In some places it is used in ``Informational Only'' mode and none of the values may be changed by the user. Normally it is in ``User Controlled (affects loading)'' mode and any of the values may be changed interactively. The georeferencing coordinate system is set by selecting the desired coordinate system from the option menu of possible systems. The currently available coordinate systems are: - Pixel: No georeferencing known. Measured in data pixels and lines. - UTM: Universal Transverse Mercator (and zone). - Long/Lat: Longitude/Latitude or Geographic. - Metre: Relative metres. World location unknown. - SPCS: State Plane Coordinate System (and zone). - Other: Other projections. To the right of the option menu is a button for selecting an ellipsoid (earth model) to use for the projection. Clicking on the ellipsoid button brings up a window with a list of the supported ellipsoids. After clicking on the desired ellipsoid and then the Accept button, the window is removed and the georeferencing string is updated with the ellipsoid selected. To the right of the ellipsoid button is a text field which contains the full georeferencing string currently in use. This includes the georeferencing coordinate system set on the option menu, plus a zone number and ellipsoid where applicable. The georeferencing string can be typed in by the user in the text field or can be built up from the selected georeference system, zone, ellipsoid. The zone number is placed after the georeferencing system, and before the ellipsoid. The ellipsoid appears at the end of the georeferencing string, and is indicated by a numeric code such as ``E000'' (Clark 1866 / NAD27) or ``E012'' (WGS 1984). The default ellipsoid is ``E000''. Each time the georeference string is changed, it is validated and reformatted. Note that changing the georeferencing system from one projection to another will not cause the bounding rectangle to be reprojected. Instead the corner values will be reinterpreted in the new georeferencing system. For a detailed list of possible georeferencing systems, ellipsoid codes, and zone codes, consult the Projections help file. The projections listed in the option menu are ones where all the parameters required for the projection are defined in the georeference string. Examples: ``UTM 11 E012'' ``SPCS 1101 E000'' ``LONG/LAT E008'' Other projections require more information to define the projection. When ``Other'' is selected from the option menu, a window with a list of supported projections is displayed. After selecting the desired projection from the list and pressing the Accept button, a ``Projection Definition'' window is displayed where the parameters required for the projection can be entered. Fields not required for the projection are not active. To the right of the georeference text field is the projection report button ``More...''. It is deactivated for georeference systems with no projection information (e.g. ``PIXEL''). When active and clicked on, it it will pop up the existing projection definition. If the projection is ``UTM'' or ``SPCS'', clicking on ``More...'' brings up the appropriate Zones window. On GeoEdit controls that are used to define a region, there will appear five additional text fields. The two labelled ``Upper Left'' define the horizontal and vertical position of the top left corner of the region. The two labelled ``Lower Right'' define the lower right corner of the region being defined. The Bounds option menu allow the bounds to be entered as Geocoded or Geographic. Geocoded means interpret the fields in the georeference units. For example, UTM (or most projections) would be eastings and northings in metres. Long/Lat coordinates may be specified in Degrees, Minutes, Seconds form (e.g. 152d30`00.00" W or 152 30 0 w or -152 30 0) or in decimal degrees (e.g. -152.5). Geographic means the bounds are interpreted in the equivalent Long/Lat values. If the projection parameters have been defined, the bounds can be specified or displayed as either Geocoded or Geographic. Note that the upper left corner specified is in fact the upper and left edges of the upper left pixel for raster images, and the lower right corner is the lower and right edges of the lower right pixel. See Also: {PROJ}Projections, {|}File Browser 2 UTM Zones and Rows The UTM projection requires a zone number in order to produce equivalent Geographic (Long/Lat) coordinates. If no UTM zone has been specified, the UTM coordinates cannot be projected to Long/Lat or other projections. When ``UTM'' is selected from the option menu of possible systems, a window with a list of zones is presented. If the Cancel button is selected, the georeference string is unchanged from when the window was popped up (e.g. ``UTM E000''). A UTM zone can be selected by clicking on the desired zone in the list and clicking the Accept button. The georeferencing string is updated with the zone selected (e.g. ``UTM 11 E000''). A window with a list of UTM rows is then popped up. The UTM row is only processed to determine if the coverage is in the Northern or Southern hemisphere. If the Cancel button is clicked the georeference string is not updated with a UTM row and the coverage is assumed to be in the Northern Hemisphere. A UTM row can be selected by clicking on the desired row in the list and clicking the Accept button. The georeferencing string is updated with the zone selected (e.g. ``UTM 11 S E000''). The UTM zone and row windows can be circumvented by typing the georeference string in the GeoEdit text field (e.g. ``utm 11'' would be put into the standard form ``UTM 11 E000''). See Also:{proj|projections|utm}UTM - Universal Transverse Mercator, {proj|utm zones}UTM - UTM Zones, {proj|utm grid zones}UTM - UTM Zone Rows 2 SPCS Zones The American State Plane projections require a zone number in order to produce equivalent Geographic (Long/Lat) coordinates. If no zone has been specified, State Plane coordinates cannot be projected to Long/Lat or other projections. When ``SPCS'' is selected from the option menu of possible systems, a window with a list of zones is presented. If the Cancel button is selected, the georeference string is unchanged from when the window was popped up (e.g. ``SPCS E000''). A State Plane zone can be selected by clicking on the desired zone in the list and clicking the Accept button. The georeferencing string is updated with the following from record selected: - the State Plane units (``SPAF'', State Plane in U.S. feet; ``SPCS'', Plane Plane in metres; ``SPIF'', State Plane in International Feet). - the State Plane zone (e.g. 406 for ``California zone 06''). - the Ellipsoid (NAD27 sets the ellipsoid to ``E000''; NAD83 sets the ellipsoid to ``E008''). The SPCS zone window can be circumvented by typing the georeference string in the GeoEdit text field (e.g. ``spaf 406'' would be put into the standard form ``SPAF 406 E000''). See Also:{proj|projections|spcs}SPCS - State Plane Coordinate System, {proj|spcs zones}SPCS - SPCS Zones 2 Projection Definition The units accessed by clicking on Other in the georeference coordinate system menu are supported projections that require more than a zone and ellipsoid. Clicking on Other will pop up a window with a list of the other projections. After clicking on the desired projection and then the Accept button, the window is removed and the Projection Definition window is popped up. If the GeoEdit control is in ``User Controlled (affects loading)'' mode, the fields that are to be defined are active and can be typed in or changed. Fields that do not apply for the projection are not active and will be blank. Most of the fields are Longitudes or Latitudes which may be specified in Degrees, Minutes, Seconds form (e.g. 152d30`00.00" W or 152 30 0 w or -152 30 0) or in decimal degrees (e.g. -152.5). In general, the False Easting and Northing fields can be defaulted as zero. See Also:{proj|projections|acea}ACEA - Albers Conical Equal-Area, {proj|projections|ae}AE - Azimuthal Equidistant, {proj|projections|ec}EC - Equidistant Conic, {proj|projections|er}ER - Equirectangular (Plate Carree), {proj|projections|gno}GNO - Gnomonic, {proj|projections|gvnp}GVNP - General Vertical Near-Side Perspective, {proj|projections|laea}LAEA - Lambert Azimuthal Equal-Area, {proj|projections|lcc}LCC - Lambert Conformal Conic, {proj|projections|long}LONG - Longitude/latitude (geographic), {proj|projections|mc}MC - Miller Cylindrical, {proj|projections|mer}MER - Mercator, {proj|projections|msc}MSC - Modified Stereographic Conformal, {proj|projections|og}OG - Orthographic, {proj|projections|om}OM - Oblique Mercator, {proj|projections|pc}PC - Polyconic, {proj|projections|ps}PS - Polar Stereographic, {proj|projections|rob}ROB - Robinson, {proj|projections|sg}SG - Stereographic, {proj|projections|sin}SIN - Sinusoidal, {proj|projections|som}SOM - Space Oblique Mercator, {proj|projections|spcs}SPCS - State Plane Coordinate System, {proj|spcs zones}SPCS - SPCS Zones, {proj|projections|tm}TM - Transverse Mercator (Gauss-Kruger), {proj|projections|ups}UPS - Universal Polar Stereographic, {proj|ups grid zones}UPS - UPS Zones, {proj|projections|utm}UTM - Universal Transverse Mercator, {proj|utm zones}UTM - UTM Zones, {proj|utm grid zones}UTM - UTM Zone Rows, {proj|projections|vdg}VDG - Van der Grinten, {proj|earth}Ellipsoids (Earth Models) 1 HELP 2 ERRORS 3 Locked PCIDSK Channel The PCIDSK channel you have selected to save to is ``Write Locked''. You may use the PACE program UNLOCK to make the channel writable; however, you might want to consider why the channel was write locked. 3 Write Access Denied You do not have write permission on the file you attempted to save to. Please check to see if you own the file, and whether you have write permissions on the file. 3 Segment Too Small The vector segment you have tried to save to is too small to contain all the data. Please select ``Create New Segment'' on the vector save panel and try again. 3 Missing Help File The request help file corresponding to the requested help topic can not be found. Help files are normally found in /pci/hlp under names such as /pci/hlp/IWORKS.HLP. Check that /pci/hlp exists, that its contents are accessible to all users, and that the help file corresponding to the requested topic exists. The local directory is also searched for help files. 3 Trapped IMP Error An IMP Error has been trapped, possibly corrupting the application data. Proceed with caution. The Trapped IMP Error messages will include an IMP Error code, which will be translated into an IMP Error message if a proper PRM.PRM file is available in the local directory. 1 File Browser The ``File Browser'' panel allows the user to view detailed information about a selected PCIDSK file. This panel contains a view option menu to allow the user to view different layers that are present in a PCIDSK file. At the top right hand side of the panel, there is a ``Delete Selection(s)'' push button that can be used to delete image channels or segments from a PCIDSK file. The multi-selection list displays layers that are present on a PCIDSK file. The lower section of the panel contains a text block that displays information about a selected layer from the selection list. Usually detailed information (such as, history of operations) can be viewed from this text block. Just below this text block, there is an input text field that displays layer descriptions. After a layer has been selected from the selection list, the user can change/edit the description of the layer via this text field. To be able to view the contents of a PCIDSK file, you must first open a PCIDSK file. This can be done via the Open menu item from either the FileBrowser File pulldown menu or from the main ImageWorks File pulldown menu. Once a PCIDSK file is selected, the selection list will display all the layers present in the file. If the selected file is locked (i.e., not writable), the user will not be able to modify or delete the file. That is, the ``Delete'' menu item from the File menu, the ``Delete'' push button, and the input text field will all be inactive. The selection list displays information according to this format: @verbatim nnnnnL[typ] program DESCRIPTIVE MESSAGE... dd-mmm-yy where: nnnnn channel number L if present means channel is write locked [typ] data type of channel: [ 8U] means 8-bit unsigned integer [16S] means 16-bit signed integer [16U] means 16-bit unsigned integer [32R] means 32-bit real program name of program that last wrote to channel dd-mmm-yy date when channel was last written to For example: 1L[ 8U] MCD 0.45 - 0.52 micrometres: Blue-Green 1-OCT-90 2 [ 8U] MCD 0.52 - 0.60 micrometres: Green 1-OCT-90 @end The area below the selection list displays additional information about a selected image layer. PCIDSK layer displays the following information: @verbatim Channel: nnnnn Type: xxxxx Creation: hh:mm dd-mmm-yy Last Update: hh:mm dd-mmm-yy Contents: xxxxxxx Locking : xxxxxxx History: (history line 1) (history line 2) . . . (history line 8) where: Channel is the channel being reported on. Type is the type of image data on the channel. Creation is the time and date that the channel was created. Last Update is the time and date that the channel was updated. Contents is user specified descriptor for channel (See MCD). Locking is write lock status (see LOCK and UNLOCK) History is the last eight channel descriptors for channel. @end The view option menu allows you to view different kind of layers present from the selected PCIDSK file. You can view a specific segment, all segments or just image channels. To be able to delete channels or segment layers from the PCIDSK file, the user must first select the layers to be deleted from the selection list. This will activate the ``Delete Selection(s)'' push button which, when pushed, will delete the selected layers. Note: Geo-referencing layers cannot be deleted. If several layers are selected (from a writable file) and one of the layers is a Geo-referencing segment layer, the Delete push button will be inactive since the Geo-referencing segment cannot be deleted. To change the description of a layer, the layer must first be selected. Note: Select only one layer from the selection list. The initial description of the layer will be displayed inside the text field. After typing in the new layer description in the input text field, pressing the ``enter'' key will directly change the layer description and update the selection list. Georeferencing information of the PCIDSK file can be viewed or edited by selecting the ``GEO Segment'' from the view option menu. 2 File Menu The ``Delete'' menu item in the File Menu of the File Browser may be used to delete the currently selected file. Some file formats have multiple associated files, while for other formats the name provided may not be the physical name of the associated file. In these cases the Delete function will report that it cannot identify the disk file associated with the currently selected database. Also, if a file is currently in use in other parts of the applications it may be impossible to delete the file. To solve this problem, terminate those parts of the application that are operating with the selected file. 2 Export File The Export File panel can be invoked from the ``Export to...'' entry of the File Browser menu. The Export File panel is used to translate files from one supported format into another. It can also be used to create a PCIDSK file with a limited number of layers or channels compared to the original. Use of the Export File panel is very simple. The default file to export from is the current file and is shown in the ``Source File'' textfield. This file can be changed by editing the textfield. Alternatively, you can press the ``Select'' button to bring up a file selector panel and make a selection from the files listed in the panel. Similarly, the output file can be specified in the ``Destination File'' textfield. The currently selected export type is shown in the ``Type'' option menu and can be changed by toggling through the option menu items to the desired format. Depending on the file type selected, additional options may have to be specified in the ``Options'' textfield. Pressing the ``?...'' button gives a listing of the available file types. Selecting a file type shows the various options required. At this point you may select, from the ``Exportable Items'' list box, the various channels, bitmaps, vectors, etc., to appear in the new file. This is accomplished by highlighting the desired items in the ``Exportable Items'' list box and pressing the ``Add'' button. The selected items will appear in the right list box labelled ``Selected Items''. The ``up'' and ``down'' arrow buttons allow you to reposition the currently selected item in the list. Some refinements to this procedure are possible . Toggling the ``View'' option menu allows you to display only one particular layer type in the ``Exportable Items'' list box. In addition, items mistakenly appearing in the ``Selected Items'' list box can be removed by selecting them and pressing the ``Remove'' button. Finally, the ``Select All'' buttons in both list boxes allow you to highlight all items in a list. This can be useful if you need all but one item, in which case you unhighlight the item, and copy over the remaining items. When you are finished selecting items to export, you press the ``Export'' button to start the process. While the file is being exported a progress monitor will appear indicating the relative level of completion of the exporting operation. See Also: GDB, FEXPORT 2 Import File The ``Import File'' panel can be invoked from the ``Import...'' entry of the File Browser menu. The Import File panel is used to translate files from any file format supported by the PCI GDB library into a PCIDSK (PCI Native) file. Importing into PCIDSK format is useful if the data must be used by PACE, if the external format is not supported for update, or if the external format is not capable of supporting required information. Also, PCIDSK format is often a more efficient format for access speed. Use of the Import File panel is very simple. The default file to import is the one already selected in the File Browser panel. The ``Select'' button beside the Source filename field launches a file selector to select a new input file. To select an output file enter the name of the new file to be created in the Destination text field, or use the Select button to launch a file selector. Note that the output file must not exist before running the import. After selecting the correct source file, and designating a name for the new output file, press the Import button to start the process. While the file is being imported a progress monitor will indicate the progress of the import process. A band interleaved PCIDSK file will be created to hold all the imported data; all imagery, vector, bitmap, and auxiliary information will be copied into the output file. See Also: GDB 2 Add Channels The ``Add Channels'' panel can be used to add 8-bit, 16-bit signed, 16-bit unsigned or 32-bit real data channels to the selected PCIDSK file. This option is only available when the user selects a file that is not locked (i.e., a writable file). NOTE: When adding channels to a PCIDSK file ensure that there is enough disk space on the hard disk where the PCIDSK file is located. The Add Channels panel will expand the PCIDSK file to accommodate the specified number of channels. 2 Subset File The Subset File panel can be invoked from the ``Subset...'' entry under the ``Utility'' menu item of the File Browser. The Subset panel is primarily used to create smaller windows of imagery, bitmaps, or vectors from a much larger file. Use of the Subset File panel is very simple. The default file to subset from is the current file (shown in the ``Source File'' textfield). This file can be changed by editing the textfield. Alternatively, you can press the ``Select'' button to bring up a file selector panel and make a selection from the files listed in the panel. Similarly, the output file can be specified in the ``Destination File'' textfield. The current subset window size is displayed in the four textfields in the ``Database Size'' Area of the panel. Just below the ``Database Size'' titlebar is a rectangular region within which appears a white and black rectangle representing the current subset window size. If the file contains imagery, and the ``Preview'' button on the titlebar is depressed, the first one or three channels of the file will be displayed in this ``Thumbnail'' region. To the right of the Thumbnail area is the ``offset widget'' a control made up of five buttons in the form of a cross, showing up, down, left, and right pointing arrows. Above the ``offset widget'' are three buttons labeled, ``Full'',``Bisect'', and ``1-1''. These buttons together with the offset widget act to change the subset selection rectangle in the Thumbnail area and the corresponding window bounds as described below. The subset window size has two primary display modes ``Corners'' and ``Offset/Size''. In Corners mode the Upper Left and Lower Right bounding corners of the windowing region are displayed, whereas in Offset/Size mode the Upper Left corner, Height, and Width of the window are given. These two modes are combined with three coordinate system choices in the option menu giving six different choices of entering or displaying the subset region information. These choices consist of ``DataBase Corners'', ``Geocoded Corners'',``Lat/Long Corners'', ``DataBase Offset/Size'',``Geocoded Offset/Size'', and ``Lat/Long Offset/Size''. To change the subset window size you can simply type the new size in the four textfields. Alternatively, you can ``grab'' a corner or side of the subset rectangle inside the Thumbnail area, by pressing the left mouse button over it, and you can ``drag'' out the desired size. The offset widget can be used to divide the file into several evenly sized files. This is done by first pressing the Full followed by the Bisect button to size the subset rectangle to 1/4 the database size. Further presses of the Bisect button will halve the rectangle in each direction. The offset widget can then be used to accurately and consistently offset this rectangle in the desired direction by pressing the corresponding arrow button. The purpose of the 1-1 button is to set the width and height of the subseting rectangles equal to one another. With the bounds entered you may select the various channels, bitmaps, vectors, etc., to appear in the new file from the ``Subsetable Items'' list box. This selection is accomplished by highlighting the desired items in the Subsetable Items list box and pressing the ``Add'' button. The selected items will appear in the right list box labelled ``Selected Layers''. The ``up'' and ``down'' arrow buttons allow you to reposition the currently selected item in the list. Some refinements to this procedure are possible . Toggling the ``View'' option menu allows you to display only one particular layer type in the Subsetable Items list box. In addition, items mistakenly appearing in the Selected Layers list box can be removed by selecting them and pressing the ``Remove'' button. Finally, the ``Select All'' buttons in both list boxes allow you to highlight all items in a list. This can be useful if you need all but one item, in which case you unhighlight the item, and copy over the remaining items. When you are finished selecting items to subset, press the ``Subset'' button to start the process. While the file is being subseted, a progress monitor will appear indicating the relative level of completion of the subseting operation. The ``Clip Vectors'' button is used to control whether vectors are clipped to the subset window. The default behaviour is for clipping to occur, hence the button is depressed. See Also: GDB 2 Reproject File @keyword{Reprojection} The Reprojection File panel can be invoked from the ``Reprojection...'' entry under the ``Utility'' menu item of the File Browser. The Reprojection panel is used to change the projection of imagery, bitmaps, or vectors contained in PCIDSK files. Use of the Reprojection panel is very simple. The default file to reproject from is the current file (shown in the ``Source File'' textfield). This file can be changed by editing the textfield. Alternatively, you can press the ``Select'' button to bring up a file selector panel and make a selection from the files listed in the panel. Similarly, the output file can be specified in the ``Destination File'' textfield. The ``Geo-Referencing Information'' area of the panel allows the user to input the size of the file in pixels and lines, together with the pixel size. The option menu indicates the manner in which the file is created regarding the variation of the input parameters. If ``Use pixels/lines and bounds'' is selected then ``pixel size'' will be varied so that a file is created with the requested pixel, lines and bounds. Similarly, the bounds will be varied if ``Use pixel/lines and resolution'' is selected. Finally the pixel and lines will be varied if ``Use bounds and resolution'' is selected. The current reprojection bounds are displayed below the ``Bounds'' label and default to the those of the current source file. The user can enter new bounds by simply typing them in. Toggling the option menu beside the ``Bounds'' label allows the user to change the format of display of the bounds from ``Geocoded'' to ``Geographic''. Note, however, if the ``Default Bounds'' button is toggled, then the bounds will be taken from what is stored in the input file. Above the Bounds label is the projection option menu which is used to select the desired projection. A more through description of this section can be found under the ``GeoEdit'' item below. The user at this point can change the sampling method by selecting an entry from the option menu. The resampling method only affects image reprojection. Bitmaps are always resampled using nearest neighbour resampling. Next to the resampling option menu is an option menu for controlling the transform order. The default value is exact, which performs a reprojection calculation for each pixel in the file. This can be very computationally expensive, so several alternatives are provided for faster, but less accurate approximations to the reprojection transform. These are computed based on 256 ground control points computed internally based on the projection transform. The 1st, 2nd, 3rd, 4th and 5th options are based on polynomial transforms, while the Thin Plate Spline option is based on fitting splines to the points. Normally 3rd order will give a fast reprojection operation, while approaching the accuracy of exact. The transform order approximation is only applied when reprojecting imagery and bitmaps. The vertices of vector layers are always transformed exactly. Problems may be encountered using approximations when operating on very large areas such as the whole world, or with very irregular regions. With the reprojection correctly specified the user can select the various channels, bitmaps, vectors, etc., to appear in the new file. This is accomplished by highlighting the desired items in the ``Source File Layers'' list box and pressing the ``Add'' button. The selected items will appear in the right list box labelled ``Destination File Layers''. The ``up'' and ``down'' arrow buttons allow you to reposition the currently selected item in the list. Some refinements to this procedure are possible . Toggling the View option menu allows you to display only one particular layer type in the Source File Layers list box. In addition, items mistakenly appearing in the Destination File Layers list box can be removed by selecting them and pressing the ``Remove'' button. Finally, the ``Select All'' buttons in both list boxes allow you to highlight all items in a list. This can be useful if you need all but one item, in which case you unhighlight the item, and copy over the remaining items. When you are finished selecting items to reproject press the ``Reproject'' button to start the process. While the file is being reprojected, a progress monitor will appear indicating the relative level of completion of the reprojecting operation. See Also: GDB, GeoEdit 1 Modify Colour The Colour Mixer is a standard control used to edit RGB colours. The control consists of a sample bar, RGB value entry textfields, with associated sliders, and an output block showing the current colour. The bar across the top offers a range of colours to sample from going from blue, through green to red. To select one of the supplied colours just click on the colour bar, on the desired colour. The current colour shows in the block to the right of the slider and text field controls. As new RGB values are entered in the text fields, modified with the sliders, or introduced using the sample bar they will be shown in this output sample.