Image processing system for image compression and decompression

An image processing system for image decompression in which a template is produced from an image to be processed with respect to each pixel so that the image is decoded into a reconstructed image by using the template, said system comprising:

• template making means for carrying out a template producing process so that a template is produced from an image with respect to one target pixel in said image, said template containing a prescribed number of reference pixels selected from among an array of pixels preceding the target pixel on a plurality of scanning lines including a current scanning line, said reference pixels having respective colors which have been detected;
• storage means for storing the colors of the reference pixels in the template produced by said template making means;
• state detection means for detecting a state index of the template from the colors of the reference pixels stored in said storage means by referring to a state index table in which correspondence between values of the state index and states of colors of the reference pixels is pre-defined;
• and
• decoding means for decoding the image with respect to each target pixel by carrying out an arithmetic decoding process in accordance with the state index detected by said state detection means, so that a reconstructed image is generated from said image,
• said template producing process carried out by said template making means comprising steps of:
• counting the number of color coincidences between the color of one of said pixels in said array and a color of the target pixel with respect to each of said pixels in said array;
• repeating said counting step until a count number which is the same as the number of pixels on the successive scanning lines is reached;
• selecting one reference pixel having a maximum count number of color coincidences from among said pixels in said array;
• updating a corresponding template data of the template table by the maximum count number of said selected reference pixel;
• repeating said selecting and updating steps until all template data corresponding to the prescribed number of reference pixels are updated in the template table;
• and
• storing the template table in said storage means, each of the colors of the reference pixels being described by corresponding template data in the template table.