Original unprocessed image
796 x 600 pixels, 195K, jpeg
Normalized image
500 x 500 pixels, 156K, jpeg

To save one of these images (in the full size indicated in the caption), right-click the desired image, and in the drop-down menu select "Save image as..." or "Save picture as...".

Normalized - the image has been cropped to include only the patch; it has been resized to a standard size (smallest axis 500 pixels); and the white and black points have been adjusted to white and black (roughly speaking, the "contrast" has been adjusted so that what should be white is white, and what should be black is black).

Retouched - starting from the normalized image, variations in lighting have been removed, color balance has been adjusted where needed, and slight imperfections in the artwork have been removed.