Drawing a Raster Image
Try it.
%!PS-Adobe-3.0
% A simple smiley face
gsave % We're mucking about with graphics state... save the original
72 72 translate % position the lower left at (72, 72)
72 72 scale % make the image 1 inch square
8 % 8 columns in the image
8 % 8 rows in the image
1 % 1-bit per pixel: black and white
[8 0 0 8 0 0] % map the unit square to (0, 0) - (8, 8)
{<c3bd665a7e5abdc3>} % the image data as a hex-encoded string
image % actually draw the image
grestore
% A 16-shade horizontal gradient
gsave
216 72 translate % lower-left of images at (216, 72)
72 144 scale % size of rendered image is 72 points by 72 points
16 % 16 pixels wide
1 % 1 pixel high
4 % 4 bits per pixel
[16 0 0 1 0 0] % transform array... maps unit square to pixels
{<0123456789ABCDEF>} % the image data itself
image % let's draw!
grestore
% A 16-tone color gradient from green to blue
gsave
360 72 translate
72 144 scale % size of rendered image is 72 points by 72 points
16 % number of samples per line
1 % number of lines
4 % bits per color channel (1, 2, 4, or 8)
[16 0 0 1 0 0] % transform array... maps unit square to pixels
{<0000000000000000>} % the red image data
{<FEDCBA9876543210>} % the green image data
{<0123456789ABCDEF>} % the blue image data
true % pull channels from separate sources
colorimage
grestore