The SAOimage desktop includes, a main image display window, a button menu panel, a display magnifier, a pan and zoom reference image, and a color bar. A color table graph window can be brought up by clicking on the color bar. Modes are selected by clicking on menu buttons in the top row of the button panel. Each menu mode brings up its own submenu buttons (the lower row in the button panel) for mode specific selections. Actions and submodes are selected by clicking on buttons in the submenu row of the menu panel. The mouse controls specific functions in both the main display window and the pan/zoom window. In the main display window, the function of the mouse is determined by a mode and submode selections from the button menu. The function is also indicated by the appearance of the mouse pointer icon.
To read an image directly from a file, give its name anywhere on the command line. The -name switch is needed only when the image file name could be mistaken for a number or switch. SAOimage recognizes the .fits and .imh filename suffixes as belonging to FITS and IRAF OIF files. All other file types must be specified by an appropriate file type switch. The array file types must be followed by width and height dimensions (unless the image is square and lacks a header). To skip over an array image header, use the -sk switch followed by the number of bytes. This can also be used to skip over entire images, if more than one are stored in the same file.
To emulate imtool, and communicate with IRAF's images.tv.display, noao.proto.imexamine, and noao.proto.tvmark tasks, either the -imtool or -pros switch must be given. The two switches differ in the type of cursor/region file written out: -imtool writes out an IRAF list containing only center coordinates, just as that of imtool; -pros writes out a full description of cursors and their dimensions which can be read by tasks in the PROS spatial package for making image masks and performing image analyses. Both file types are ASCII and can be read and edited by the user. Either type of file can be read back in to reproduce the saved cursors.
A new command line can be entered at any time, by selecting the new button in the etc submenu or striking the N key on the keyboard, allowing the user to read in new images, change in and out of -imtool or -pros mode, set new scaling parameters, or change the number of reserved display color cells. When a new command line is requested, the previous command line is presented in an emacs-like popup editor for editing. Ctrl-N clears the previous line. Striking the RETURN key enters the line in the popup window as the new command. Ctrl-C returns with no action taken.
The button interface is designed to be user friendly. The novice user is encouraged to try any and all buttons to become familiar with their functions. The QUIT button terminates the SAOimage program.
MODES AND THE MOUSE
Most mouse interactions are based on mouse dragging (holding a button down while moving the mouse). The user should try clicking and/or dragging the mouse in each subwindow to become familiar with its functions. Modes selected in the button panel determine the response to the mouse buttons in the main display window.
In Scale mode, the mouse buttons control blinking of displays (saved by clicking with the same mouse button in the blink submenu button). In Color mode, mouse dragging stretches and shifts the color map as per the contrast/bias, threshold/saturation, and gamma submenu selections.
In the color graph window, color table vertexes may be added or moved by clicking/dragging with the LEFT (red), MIDDLE (green), or RIGHT (blue) mouse buttons. The graph will update continuously only if tracking is turned on.
In Cursor mode, the mouse controls the size and locations of cursors. The rule is: LEFT button for position, MIDDLE button for size, and RIGHT button for angle or deletion (depending on the cursor). For box and ellipse, MIDDLE button sizing is restrictd, depending on whether dragging started on a side or near a corner. With the point cursor, LEFT and MIDDLE save the current positions with a + or - indication, while the RIGHT button deletes saved points. For the polygon cursor, the MIDDLE button adds or moves a single vertex, while the RIGHT button will delete vertexes. When annuli is set for box, circle, or ellipse, the MIDDLE button adds or resizes an annulus, while the RIGHT button deletes annuli. For manipulating cursors, the ovlay selection in the Color submenu, enables the cursor to track smoothly as an overlay graphic. The region submenu button selection up another submenu with selections to display and review regions, and read from or write to disk files.
In Pan mode, and in the pan window (regardless of mode), the LEFT button selects the center of the image, while the MIDDLE button selects the edge of the display, zoomed with the given center. When either function is dragged, the rectangle in the pan window shows the area that would appear in the display when the button is released.
KEYS
While in the cursor mode, the S and E keys, save the current cursor in a region list, while the D and DELETE keys can be used to forget a region. At any time, with the pointer in the display or pan windows, the T key prints a table of pixel values at the pointer position to STDOUT. The 4 arrow keys should work for fine movement of the pointer in any window. The SHIFT and SHIFT LOCK keys will reverse the magnifier window, color graph window and coordinate tracking status. The N key summons the pop-up editor for new command input. Most command line switches (except -d, -g, -gd, -red, -green, -blue, and -vertgraph) will be accepted at any time. The A key raises and redraws all of SAOimage's windows.
FOR MORE INFO
Detailed descriptions of all functions are given in SAOimage's user manual sections.
BUGS
SAOimage does not allocate its own colormap and thus fails with static color (i.e. NeWS) window managers. Resource settings of a user's default preferences are not read. The area of the polygon cursor is not calculated if its sides touch or cross. The user manual is simple text and lacks a title page, index, and table of contents.