+
+void
+remap_image (Screen *screen, Window window, Colormap cmap, XImage *image)
+{
+ Display *dpy = DisplayOfScreen (screen);
+ unsigned long map[4097];
+ int x, y, i;
+ int cells;
+ XColor colors[4097];
+
+ if (image->depth == 8)
+ cells = 256;
+ else if (image->depth == 12)
+ cells = 4096;
+ else
+ abort();
+
+ memset(map, -1, sizeof(*map));
+ memset(colors, -1, sizeof(*colors));
+
+ for (i = 0; i < cells; i++)
+ colors[i].pixel = i;
+ XQueryColors (dpy, cmap, colors, cells);
+
+ if (grab_verbose_p)
+ fprintf(stderr, "%s: building table for %d bit image\n",
+ progname, image->depth);
+
+ for (i = 0; i < cells; i++)
+ {
+ unsigned short r, g, b;
+
+ if (cells == 256)
+ {
+ /* "RRR GGG BB" In an 8 bit map. Convert that to
+ "RRR RRR RR" "GGG GGG GG" "BB BB BB BB" to give
+ an even spread. */
+ r = (i & 0x07);
+ g = (i & 0x38) >> 3;
+ b = (i & 0xC0) >> 6;
+
+ r = ((r << 13) | (r << 10) | (r << 7) | (r << 4) | (r << 1));
+ g = ((g << 13) | (g << 10) | (g << 7) | (g << 4) | (g << 1));
+ b = ((b << 14) | (b << 12) | (b << 10) | (b << 8) |
+ (b << 6) | (b << 4) | (b << 2) | b);
+ }
+ else
+ {
+ /* "RRRR GGGG BBBB" In a 12 bit map. Convert that to
+ "RRRR RRRR" "GGGG GGGG" "BBBB BBBB" to give an even
+ spread. */
+ r = (i & 0x00F);
+ g = (i & 0x0F0) >> 4;
+ b = (i & 0xF00) >> 8;
+
+ r = (r << 12) | (r << 8) | (r << 4) | r;
+ g = (g << 12) | (g << 8) | (g << 4) | g;
+ b = (b << 12) | (b << 8) | (b << 4) | b;
+ }
+
+ map[i] = find_closest_pixel (colors, cells, r, g, b);
+ }
+
+ if (grab_verbose_p)
+ fprintf(stderr, "%s: remapping colors in %d bit image\n",
+ progname, image->depth);
+
+ for (y = 0; y < image->height; y++)
+ for (x = 0; x < image->width; x++)
+ {
+ unsigned long pixel = XGetPixel(image, x, y);
+ if (pixel >= cells) abort();
+ XPutPixel(image, x, y, map[pixel]);
+ }
+}
+
+
+#endif /* HAVE_READ_DISPLAY_EXTENSION */