the expanded - range image digitizing apparatus utilizes a light - attenuating layer in concert with solid - state light detectors of limited dynamic range to provide a means for digitizing wide - dynamic - range images . the light - attenuating layer is placed in close contact with an image - containing medium . the light - attenuating layer is comprised of groups of regions replicated throughout the light - attenuating layer where each region in a group attenuates light passing through to a different degree and each group is the same in size and shape as a picture element of the image being digitized . when the image - containing medium is illuminated , the emerging light power from one of the regions of a group is of the proper magnitude to cause an associated detector to respond within its dynamic range . the emerging light power from the corresponding picture element of the image is then determined by multiplying the detected light power by the attenuation factor of the region producing the proper detector response .