Sun/IRAF Site Manager's Guide

4.3. Image Display capabilities

Image display for IRAF running in the SunView environment is provided by the imtool display server prototype. The current imtool program provides a basic display capability, including programmed access from the IRAF environment to load images, interactive windowing of the display, pseudocolor, dithered (Postscript) or Sun rasterfile image hardcopy, an interactive image cursor readback capability, zoom and pan, a variety of frame buffer sizes, independent frame buffer and display window sizing, up to four frames, each with its own state, and programmable frame blink. imtool runs as a display server, meaning that it sits idle most of the time, waiting for some client, e.g., IRAF, to send it an image to be displayed via some form of interprocess communication.

To use imtool from within IRAF one must define the logical device and enable image cursor input. For example,

 cl> reset stdimage = imt512

would configure IRAF and imtool for use with a 512 pixel square frame buffer (image display image memory). A variety of frame buffer sizes are predefined; see the imtoolrc file (normally in /usr/local/lib) for a complete list of possible configurations.

The image cursor is enabled by

 cl> reset stdimcur = stdimage

This is the default for Sun/IRAF. Setting stdimcur to "text" disables the image cursor, allowing cursor values to be typed in interactively in the terminal window. This is useful, for example, when running image oriented programs from a simple terminal.

The standard IRAF interface to the display server is the display program in the TV package. Automatic determination of the optimum intensity mapping to the 200 imtool greylevels is provided. Entire frames can be displayed, or one can write to subregions of the display. Other programs useful with the image display include imexamine, used to interactively examine images under image cursor control, imedit, used to edit images using the display, and tvmark, used to write color graphics into a display frame.

The display server has the capability of displaying the cursor (mouse) position and pixel value in image pixel units as the mouse is moved about in the window. In addition, text file cursor lists can be generated and displayed, or the image cursor can be read interactively from within IRAF. The image cursor may be called up at any time by typing

 cl> =imcur

into the CL. Applications programs which read the interactive image cursor will do this automatically during program execution.

Imtool supports a number of special function keys and other keyboard accelerators, a frame menu, a setup panel and so on. Further information on the operation of imtool is given in the online manual page, imtool(l) (a UNIX level manpage). Further information on the use of the image cursor is given in the online help page cursors.