1require ("png");
2define slsh_main ()
3{
4   variable image_row = [0:255];
5   variable gray_img = UChar_Type[32,256];
6   variable i;
7   _for i (0, 31, 1) gray_img[i,*] = image_row;
8
9   variable cmaps = png_get_colormap_names ();
10   variable n = length (cmaps);
11   variable rgb_image = UInt32_Type [32*n, 256];
12   _for i (0, n-1, 1)
13     {
14	variable cmap = cmaps[i];
15	rgb_image[[i*32+[0:31]],*] = png_gray_to_rgb (gray_img, cmap);
16     }
17   png_write ("colormap.png", rgb_image);
18}
19