The 2 inch slap images are in raw format, 1600 (Width) x 950 (Height) pixels. This are captured with a "film" between the platen and the fingerprints so that "noise" was captured in place of the friction ridges in the same manner as the 3 inch slap images.
The 3 inch slap images are in raw format, 1600 (Width) x 1500 (Height) pixels. Since NIST can't release SBU data, these slaps were captured with a "film" between the platen and the fingerprints so that "noise" was captured in place of the friction ridges.