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FullView Version 1.0I June 6, 1993 Copyright (C) 1992, 1993 Soloca, Inc. All Rights Reserved written by Rick Coupland Users Manual Soloca, Inc. P. O. Box 31208 Flagstaff, AZ 86003-1208 Internet: rick@world.std.COM FEATURES FullView is an image viewer program for 80286, 80386 or 80486 based systems with a VGA or Super VGA display adapter. FullView features fast decompression and display of all supported image formats. The 15 bit (32,768 color) modes of Super VGA cards using the Tseng 4000 and the Sierra HiColor DAC are supported. All graphic display modes, include 15 bit, 16 bit and 24 bit direct color modes, for Super VGA cards using the VESA VGA BIOS Extensions are also supported. Images of any size may be displayed. Images whose size exceeds the screen size, in the current display mode, will either be scaled to fit within the screen boundaries or may be scrolled horizontally and/or vertically. The following types of image files may be displayed: JPEG (.JPG) files, JFIF format; 24 bit full color or 8 bit monochrome. Targa (.TGA) files; all formats. Graphics Interchange Format (.GIF) files; both the 87a and 89a standards are supported. ACKNOWLEDGEMENTS This software is based in part on the work of the "Independent JPEG Group". The "Independent JPEG Group" assumes no responsibility for any claims arising from the use of FullView. The Graphics Interchange Format(c) is the Copyright property of CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe Incorporated. SHAREWARE NOTICE FullView is distributed as shareware. You are welcome to use FullView without charge for an evaluation period of 15 days. If you continue to use FullView after the evaluation period, you are obligated to register by paying a $25 license fee to Soloca, Inc. Please use the included registration form (file REGISTER.TXT) when registering. Registered users will receive a diskette containing the current version of FullView, a set of high quality full color JPEG images and the JPEG conversion utilities from the "Independent JPEG Group". Registered users of version 1.0 will also be entitled to a free upgrade to version 1.1 when it becomes available. As additional new versions become available notices will be mailed to registered users who may upgrade for a small fee. You are encouraged to share FullView with others and to post it on bulletin boards. If you do so, please pass along the complete unmodified archive. BBS SysOps and shareware disk distributers may contact Soloca, Inc. for a free copy of the latest version of FullView. Comments, suggestions or bug reports can be sent to me (Rick Coupland) by electronic mail. Internet: rick@world.std.com Please contact Soloca, Inc. regarding site license agreements, redistribution of FullView, or other special licensing needs. SOFTWARE/HARDWARE REQUIREMENTS Hardware: IBM PC AT or compatible with Intel 80286 or later CPU VGA or Super VGA display adapter Software: MS-DOS or PC-DOS version 2.0 or later Extended Super VGA display modes are available only if the VGA board uses one of the supported chip sets or if the VESA Super VGA BIOS extensions are supported. Otherwise, FullView will be limited to those display modes available on a standard IBM VGA. The following Super VGA chip sets are currently supported: Chips & Technology 82C451, 82C452 and 82C453 Paradise (Western Digital) PVGA1A, WD90C00, WD90C10 and WD90C11 Tseng Labs ET3000, ET4000 & ET4000 with Sierra HiColor DAC VESA stands for "Video Electronics Standards Association". VESA has defined a set of extensions to the video BIOS which provide a method of accessing Super VGA capabilities. Some Super VGA boards provide the VESA extensions in the video ROM BIOS. Other vendors provide loadable drivers which provide the VESA BIOS extensions. Drivers for several types of Super VGA boards are available directly from VESA. Their address and phone numbers are given below: Video Electronics Standards Association 2150 North First Street Suite 360 San Jose CA 95131-2020 Voice: 408-435-0333 FAX: 408-435-8225 CONFIGURATION When FullView starts up, it performs tests to identify the types of display adapter(s) which are installed. Normally, configuration is automatic. You can use the -a option find out the type of display adapter which FullView has found and the display modes it thinks are available. In some cases, not all of the listed display modes will function properly. This could be the case if your monitor is not able to sync properly in all display modes. If this occurs, you can use the -x option to disable the display modes which do not work properly on your system. This can most conveniently be done using a configuration file. See the "Options" and "Configuration File" sections of this document for detailed information these subjects. USAGE FullView utilizes a simple command line interface to specify files and options. The general form of the command line is shown below. fv [-options] file1 file2 ... For normal viewing, you will only need to specify the names of the files containing the images you wish to view. Fullview will display the images in the files in the same order as the file names appear on the command line. FullView will attempt to select the most appropriate display mode for each image. When you are finished looking at an image, press the Enter key or space bar to advance to the next image. Wildcard characters ("*" and "?") may also be used in the file names given on the command line. A file name containing wildcard characters represents a pattern which may be matched by one or more actual files. Refer to the DOS User's Guide for further information on the use of wildcards. To view all of the files in the current directory, enter the following command: fv *.* When this command is entered, all of the image files in the current directory will be processed in alphabetical order. All image files whose type is recognized by FullView will be displayed. Files which are not image files or are of a type not supported by FullView cause an error message to be displayed. After displaying an error message, FullView will pause until a key is depressed before proceding to the next file. To view files in other directories, you may give complete path names rather than simple file names. For example, to view all .JPG files in the "\pub\pics" directory on the "C" drive, you would use the following command: fv C:\PUB\PICS\*.JPG Both backward slash (\) and forward slash (/) characters are recognized as directory separator characters. Thus, the preceding command could also be given as shown below: fv C:/PUB/PICS/*.JPG Files are normally expected to have a file name extension corresponding to the type of the file. If a file does have a file name extension, the extension is used to determine the file type. If a file name has no extension, the first few bytes of the file are read to determine the type. Options Options are used to alter the default behavior of FullView. Options may be specified on the command line and may also be specified in a configuration file. Options are distinguished from file names by a "-" prefix character. Some options require a parameter value. When these options are used, the associated parameter value must immediately follow the option, with or without in intervening space. For example, "-m 13" and "-m13" are both valid. Options which do not require a parameter are used to enable or disable a feature or mode of operation and are referred to (in this document) as binary options. Each instance of a binary option in the configuration file or command line toggles the option to the opposite of its prior state. Binary options are processed in this way in order to allow the default settings to be changed using the configuration file while preserving the ability to override the defaults on the command line. Multiple binary options may either be specified as separate words (eg. "-c -i") or may be concatenated into a single word (eg. "-ci"). The follow is a complete list of the FullView options: -a Causes the video adapter configuration information to be written to standard out. This information consists of the adapter type, the amount of display memory and a list of available graphic display modes. By default this information is not displayed. -b Disables the generation of a tone after each image has been decompressed and displayed. This tone signals that FullView has finished reading an image file and is ready to accept keyboard commands. -c Sets continuous mode. Continuous mode causes FullView to repeatedly display the list of files specified on the command line until aborted. By default, FullView exits when finished displaying the last file. -d Disables Floyd Steinberg dithering for monochrome images and images displayed in non-paletted display modes. In the current version, dithering is always used when full color images are displayed in paletted display modes. Refer to the section on "Color Quantization and Dithering" for more information. -e By default, FullView will display an error message complaining about files which are not in a recognizable image file format. This option suppresses these error messages. -i Causes information to be displayed about each image. This information is displayed in window at the bottom of the screen when FullView finishes reading the image file. The information window is removed from the screen when any key is depressed. If the -i option was also specified, the window will be removed when the specified period of time has elapsed. The image information window can also be displayed by pressing the "I" key while an image is on the screen. -m nn Causes all images to be displayed using the specified display mode. The parameter (nn) is a hex number giving the ID of the display mode to be used. A list of usable graphic display modes can be obtained by using the -a option. -p rgb Specifies the number of red, green and blue levels for a uniform palette to be used with Floyd Steinberg dithering when displaying an image which contains more colors than are available in the current display mode. The parameter (rgb) consists of three decimal digits giving the number of red, green and blue levels respectively. The product of these three values must be less than or equal to the number of colors available in the current display mode (normally 256 or 16). Color quantization and dithering are discussed in greater detail in a later section. -s This option disables scaling. If an image is displayed whose size exceeds the size of the display screen, as much of the image as will fit is written into display memory and the screen is positioned to the uppper left corner of the image. The arrow keys may then be used to view other portions of the image which are in display memory. By default, images which are larger than the screen will be scaled so that the entire image fits within the screen boundaries. -t n Causes FullView to advance to the next image after an image has been displayed for the specified period of time. The parameter (n) is a decimal integer giving the number of seconds to display each image. By default, FullView does not advance to the next image until the Enter key or space bar is pressed. -v This option restricts FullView to using only those display modes and capabilities available on a standard IBM VGA. -V This option forces usage of the VESA BIOS interface even if the display adapter is based on a supported Super VGA chip set. If the VESA BIOS extensions are not available, this option has the same effect as the "-v" option. By default, the VESA BIOS interface will be used only if the display adapter is not based on a supported Super VGA chip set. -x nn This option inhibits the use of the specified display mode. The parameter (nn) is a hex integer giving the ID of a display mode. The -x may occur multiple times on the command line or in the config file in order to inhibit the usage of multiple display modes. This option is intended to handle situations in which one or more of the display modes provided by the display adapter do not function correctly on a particular system. A list of the available graphic display modes may be obtained by using the -a option. Examples To obtain a usage statement describing command line format and options, enter the following command: fv To display information about the display adapter type and available display modes, enter the following command: fv -a To display a GIF file called "XYZ.GIF", enter the following command: fv xyz.gif To display all JPEG files in the current directory, enter the following: fv *.jpg To display all displayable image files in the current directory and ignore all other files, enter the following: fv -e *.* To start a continuous display of all image files in the current directory with a 5 second display of each image, enter the following: fv -ce -t 5 *.* Config File The FullView config file provides a method of changing the default settings for any of the options. The config file has a file name of "FULLVIEW.CNF" and should be located in the same directory as the "FV.EXE" file. The contents of the file consists of one or more lines of ASCII text. Each line contains one or more option specifications in the same format as they would appear on the command line. Blank lines are ignored. A ";" character is used to introduce comments. All characters following a ";" character on any line are ignored. When FullView first starts up it searches for a config file first in the current directory. If the config file is not found in the current directory, the directory from which FullView was run (the directory containing FV.EXE) is searched next. If a config file is found, the file is read and the options contained in the file are processed. If you find that you are frequently using the same set of command line options when you run FullView, you may wish to create a config file containing these options. Any of the option settings contained in the config file, with the exception of -x, can be overridden from the command line. Keyboard Commands Keyboard commands are used to control the operation of FullView. All keyboard commands consist of a single keystroke. Most of the commands can only be processed after FullView has finished reading and decoding an image file, while the image is on the screen. However, three of commands (Esc, Enter and Space) can be entered at any time. In the current release of FullView, most of the keyboard commands are concerned with scrolling the image on the screen. If sufficient display memory is available, horizontal and vertical scrolling are enabled whenever an image is displayed which is larger than the visible screen area in the current display mode. If the display memory is large enough, the entire image will be written to display memory and it will be possible to scroll to the boundaries of the image. Otherwise, the image will be truncated to fit within the available display memory. One some VGA boards, only the first 64K of display memory is usable in mode 13 (320x200, 256 colors). In this case, FullView will truncate the image to fit within the first 64K of display memory when displaying an image using mode 13. The follow is a description of the keyboard commands: Esc Terminate execution. Enter Advance to next image. If the last image is being displayed, terminate execution unless the -c option is set. Space This key has the same effect as the Enter key. F1 Display a help screen containing a brief description of the keyboard commands. The help screen will be removed when any key is pressed. h This key has the same effect as the F1 key. i Display a window at the bottom of the screen giving information about the current image and display mode. This window will be removed when any key is pressed. Down Arrow Scroll towards the bottom of the image. Up Arrow Scroll towards the top of the image. Left Arrow Scroll towards the left edge of the image. Right Arrow Scroll towards the right edge of the image. + Increase the scroll rate. - Decrease the scroll rate. Scrolling is initiated when an arrow key is depressed and stopped when the key is released. Diagonal scrolling may performed by holding down the up or down arrow keys and the left or right arrow keys simultaneously. If an arrow key is pressed while a Control key is held down, the image will be scrolled 1 pixel in the indicated direction. Using Fullview From Microsoft Windows FullView is a DOS application which was designed to be compatible with Microsoft Windows. The Windows file manager can be configured to associate ".JPG", ".GIF" and ".TGA" files with FullView. Once a file type has been associated with FullView, you only need to "double click" or press the Enter key to display the file. The following procedure may be used associate a file type with FullView: 1. Using the mouse or arrow keys, select a file of the desired type. The selected file will be displayed in reverse video. 2. Select the "Associate" item from the File Manager's "File" menu. 3. Type in the full path name of the FV.EXE file in the space provided and press Enter. For example, if FV.EXE is in the \BIN directory of the C: disk, you would type "C:\BIN\FV.EXE". Of course, FullView can also be run from a DOS window in the same manner as it would be run directly under DOS. COLOR QUANTIZATION AND DITHERING Color quantization refers to the process of reducing the resolution of the color values in an image. This is required when the number of colors in an image exceeds the number of colors which may displayed at the same time. Color quantization is also required when the color resolution of the image exceeds the color resolution of the display device. The most straightforward representation of a color image is a format which gives the color of each pixel as a value for each of three color components (usually red, green and blue). In this document I will refer to this type of format as a full-color format. In most cases 8 bits are used to represent the value of each color component, giving a total of 24 bits per pixel. This gives sufficient color resolution to approach the limits of the ability of the human eye to discriminate color. Display devices such as the VGA utilize a set of registers for storing the colors which may be displayed. The set of colors in the color registers is called the palette. The colors in the palette are numbered so that an index is associated with each color. Each pixel of the image data contains the index of the palette color which is to be displayed for that pixel. This method of representing an image is referred to as a paletted format. The primary advantage of paletted formats is that the amount of memory required to store the image is significantly reduced. Another advantage is that the colors in the image can be manipulated by changing only the palette colors. The disadvantage is that total number of colors which may appear in any one image is quite limited (usually 256 colors or less). This limits the accuracy to which a full color image can be represented. In order to display a full color image on a VGA, it must be converted to a paletted format. The first step in this conversion is to select a palette. Ideally, the palette should be chosen in such a way as to allow all of the colors in the image to be approximated as closely as possible. This is a non-trivial problem and several algorithms have been developed for doing this. Most of these tend to be rather slow and take large amounts of memory. Once a palette has been selected, all of the pixels in the image must be assigned to one of the palette colors. This can be done by assigning the palette color to each pixel which most closely matches the original pixel color. Another technique which can used for assigning the pixels to palette colors is called dithering. Dithering makes use of the fact that the eye averages the colors of neighboring pixels in a high resolution image. Dithering adjusts the color of each pixel in such a way that the average color of small areas more closely matches the color of that area in the original image. In effect, dithering trades off spatial resolution for improved color accuracy. In high resolution modes, this results in a display which looks more like the original image. At lower resolutions, individual pixels are more visible and the image appears fuzzy. Dithering can be quite effective at reducing the "banding" which occurs when smoothly shaded regions of an image are quantized. FullView uses uses a uniform palette and Floyd Steinberg dithering. The palette is constructed by first calculating a pre-defined number of equally spaced levels which span the entire range for each of the red, green and blue components. The palette then consists of all combinations of these levels. For a palette of 256 colors, FullView uses 7 red levels, 9 green levels and 4 blue levels by default. These values are used because the eye is not equally sensitive to all colors of light. The ratios given in most texts are .30 red, .59 green and .11 blue. The number of levels for each of the components may be directly specified using the -p option. However, the default values will give the best results for most images. This method is quite fast and gives reasonable results in the higher resolution modes. On a 19 inch monitor in a 1024x768, 256 color mode, the results are quite acceptable. At lower resolutions, the image may appear somewhat fuzzy. Most VGA and Super VGA boards provide only 6 bits or 64 levels per color component. When 8 bit grayscale images are displayed on these boards, the 256 shades of gray must be quantized down to 64 shades. This can produce visible effects in some images. FullView can use dithering in this case to reduce these effects. The test image "gray1.jpg", included with the shareware distribution of FullView, shows an extreme example of this. Try looking at this image both with dithering enabled and disabled (-d option) to see the effect of dithering on monochrome images. FullView can also use dithering when displaying full color images in the 16 bit modes provided by the Sierra HiColor DAC. These are non-paletted modes which provide 5 bits (32 levels) per color component. The effects of color quantization when displaying 24 bit images in these modes can be quite noticeable in some images. Dithering reduces these effects dramatically. About JPEG JPEG is a standardized method of compressing full color or monochrome images. JPEG stands for "Joint Photographic Experts Group". This is the name of a committee which developed the JPEG standard. JPEG was designed to be used for images of natural, real world, scenes. The primary advantage of JPEG is that it is capable of very high compression ratios. JPEG is a "lossy" compression method. This means that some of the information in a digitized image is lost when the image is compressed and decompressed using JPEG. The amount of loss can be controlled by adjusting compression parameters. Even though information is lost, very good compression can be obtained with little or no visible change to the image. The JPEG standard does not specify a concrete file format. This has resulted in a number of incompatible implementations by several vendors. FullView uses the JFIF (JPEG File Interchange Format) which was coordinated by C-Cube Microsystems and agreed to by a number of major commercial JPEG vendors. This format is likely to become a de facto standard for image files using JPEG compression. A group of programmers, called the "The Independent JPEG Group", have developed portable software for JPEG compression and decompression. They have made the source code for this software freely available and have allowed the royalty free use of this software in commercial products. FullView uses portions of this software for JPEG decompression. Some portions have been recoded for improved performance on a PC. I wish to thank Tom Lane and the other members of the members of "The Independent JPEG Group" for the use of this high quality software in FullView. The distribution from the "Independent JPEG Group" contains two conversion utilities called cjpeg and djpeg. The cjpeg utility converts image files in a variety of different formats into JPEG JFIF files. The djpeg utility converts from JPEG JFIF format to a variety of output formats and can perform color quantization using Heckbert's median cut algorithm. DOS ".EXE" files and supporting documentation for these two utilities are included on the diskette distributed to registered FullView users. The entire source distribution from the "Independent JPEG Group" can be obtained on the internet from ftp.uu.net in the graphics/jpeg directory or from Compuserve in the GRAPHSUPPORT forum. New Features in Version 1.0H Faster JPEG decompression. Scaling of images to fit display. Full Support for version 1.2 of the Super VGA VESA BIOS extensions. This includes support for direct color display modes.