Patent ID: 8526766

Claim:
A method for creating a composite digital image of information printed or written on a page, the composite digital image including a plurality of pixels and each pixel including two or more bits, said method comprising: designating different portions of the information on the page as different layers; storing two or more constituent images, each constituent image comprising a digital image of one of the different layers, each constituent image including a number of pixels that is the same as the number of pixels in the composite digital image, each pixel of the constituent image including a number of bits that is less than the number of bits per pixel of the composite digital image; associating each bit of each constituent image with at least one specified bit of each pixel of the composite digital image to define a bit pattern for each pixel of the composite digital image; defining at least two color sets by associating a color with each possible bit pattern of the pixels of the composite digital image, whereby the colors associated with the possible bit patterns for each color set will determine which of the different layers will be visible and the color of each visible layer for the given color set; and displaying one or more of the different layers by selecting the color set corresponding to the layers to be displayed and displaying each pixel of the composite digital image in the color associated with the bit pattern of that pixel for the selected color set, wherein the page is an assessment document, and said method comprises designating at least a layer comprising a student response.