color palette menu

These menus are for creating, modifying, and saving color palettes. By using a palette file, you can view black & white images in pseudocolor. This can be helpful when you are trying to make very small changes in image intensity visible to the naked eye.

Black & white images use the numbers from 0 to 255 to represent different intensities or grey shades. Zero represents black, and 255, white. Neutral grey is about 128. Ordinarily, when you display a black & white image, the system uses a portion of its color table that is dedicated to grey shades to approximate the true intensities. When you request a pseudocolor display of a black & white image, however, things happen differently. The system takes the color palette you specify, and uses it to assign a color to each of the numbers from 0 to 255. Then, when it displays the image, it uses these colors instead of the usual grey shades. For example, if your image had a pixel whose intensity was 79, the system would look at the eightieth slot in the palette, and use the color it found there instead of the grey shade it would ordinarily use for intensity 79.

The procedure for creating a color palette is as follows:

Go into the Modify Palette menu, and load a palette with colors however you like.
Go into the Save Palette File menu, and save the palette to disk.

You can edit previously-created palettes by going into the Get Palette File menu, and recalling one from disk, and then going into the Modify Palette menu.