| 摘要 |
Disclosed is a method and apparatus for converting the color borders of a raster image into a more abstract mathematical representation that can be converted into a vector format without significantly fragmenting the image. The invention involves scanning a neighborhood of cells in the form of a square matrix through the raster image in order to generate a surface string (or an indicia thereof) representing the color border at each pixel, and then to sequence the surface strings into string sequences which represent the color borders. By assigning color values to the neighborhood of cells that indicate whether the perimeter cells are the same or different in color than the center cell, the present invention is capable of defining color borders in raster images comprising three or more colors (as opposed to black and white images). The string sequences are generated by sequencing together string IDs rather than simple slopes which provides optimal information for generating vectors. Another enabling aspect of the present invention is to sequence the surface strings according to a a priority assigned to surface strings based on their location in the image and their type (protruding corner, corner, step, etc.).
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