SETBACK(1) X Version 11 SETBACK(1) 27 November 1989 NAME setback - Set background to image SYNOPSIS setback file [ options ] DESCRIPTION setback tiles the screen background with an image. If the image requires more colors than are available for private use by an X11 client, it displays a quantized copy of the image which uses a smaller number of colors. When appropriate, setback may convert the image automatically to a different representation to suit the screen's default visual. This may involve converting in either direction between RGB and color- mapped format, and it may involve quantizing the image to force it to use only the maximum number of colors available. Similarly, it may convert color to grayscale or monochrome (dithered black and white). The file argument can be a specific filename or a "base" filename for an image. If file cannot be opened, setback tries file.Z, file.p, and file.p.Z. Any file whose names ends with .Z is presumed to be in compressed format. OPTIONS This program accepts the standard options listed below. They are listed as command line options, but can also be supplied as X resources; for example, "-force monochrome" on the command line has the same effect as "dispimg.force: monochrome". -colorinstances scope -colorinstances private selects use of privately allocated (read/write) colors, -colorinstances shared selects use of shared (read only) colors. Private colors cannot be shared with other clients using the same color map, but they allow better image quality than shared colors. -colormap scope -colormap private selects use of a private color map. -colormap shared selects shared use of a default color map. A private color map allows the best possible color rendition for the image, but may cause annoying color changes on the screen as the cursor moves into or out of the image's window. -display displayname Name of X server to use, including screen number. -force restriction -force grayscale forces conversion of a color image to grayscale. - 1 - Formatted: April 26, 2024 SETBACK(1) X Version 11 SETBACK(1) 27 November 1989 -force monochrome forces conversion of a color or grayscale image to monochrome (dithered black and white). -force nothing retains as much of the image's original data as possible. -maxcolors n This specifies the maximum number of colors (2 - 256) to be retained in a color-mapped image. The maximum depends on how many colors the display hardware supports. AUTHOR Paul Raveling, USC Information Sciences Institute - 2 - Formatted: April 26, 2024