This is documentation for Mathematica 4, which was
based on an earlier version of the Wolfram Language.

Raster

Raster[, , ... , ... ] is a two-dimensional graphics primitive which represents a rectangular array of gray cells.

Raster[array, ColorFunction -> f] specifies that each cell should be rendered using the graphics directives obtained by applying the function f to the scaled value of the cell.

Raster[array, ColorFunction -> Hue] generates an array in which cell values are specified by hues.

With the option ColorFunctionScaling -> False the original cell values , rather than scaled cell values, are fed to the color function.

With the default setting ColorFunctionScaling -> True cell values in Raster[array] outside the range 0 to 1 are clipped.

If array has dimensions m, n, then Raster[array] is assumed to occupy the rectangle Rectangle[0, 0, m, n].

Raster[array, xmin, ymin, xmax, ymax] specifies that the raster should be taken instead to fill the rectangle Rectangle[xmin, ymin, xmax, ymax].

Scaled and Offset can be used to specify the coordinates for the rectangle.

Raster[array, rect, zmin, zmax] specifies that cell values should be scaled so that zmin corresponds to 0 and zmax corresponds to 1. Cell values outside this range are clipped.

See The Mathematica Book: Section 2.9.2 and Section 2.9.2.