Detection and segmentation of sweeps in color graphics images

Business graphics are an important class of digital imagery. Such images are computer-generated, and comprise synthetic elements such as solid fills, line art, and color sweeps. Often these images are first printed and then scanned for further electronic reuse. The printing and scanning process destroys the synthetic structure of a graphics image, and furthermore introduces distortions due to halftoning and other forms of printer and scanner noise. Subsequent reproductions usually amplify these distortions thus resulting in rapid degradation of image quality. It would thus be desirable to detect and reconstruct the original synthetic structure from the scanned image. This paper presents an effort in this direction, namely a method to detect color sweeps in scanned images. Once detected, the synthetic signature of the sweep is derived, namely its starting and ending color. This information can be used to optimize subsequent image processing operations such as rendering to an output device, or image compression. This work represents a novel application of known image processing techniques to extract semantic information from graphics images.