Abstract: In an image recognition method of recognizing a plurality of images from an input image, the plurality of images to be recognized including at least one of a specific image and images provided by rotating the specific image, the method includes the steps of: preparing at least one of mask areas on a window area for each image to be recognized, the window area being structured by cells which are arrayed in two-dimensionally, the cell being formed of at least one pixel, the mask area being structured by at least one of the cells and corresponding to an area representing a feature of the image to be recognized; first determining whether or not the image to be recognized exists based on the result of subjecting pixel density values of the input image in the mask area to operation for each image to be recognized; and second determining whether or not any of the plurality of images to be recognized exists in the window area based on the determination result of the first determining step.

Abstract: In an image recognition method of recognizing a plurality of images from an input image, the plurality of images to be recognized including at least one of a specific image and images provided by rotating the specific image, the method includes the steps of: preparing at least one of mask areas on a window area for each image to be recognized, the window area being structured by cells which are arrayed in two-dimensionally, the cell being formed of at least one pixel, the mask area being structured by at least one of the cells and corresponding to an area representing a feature of the image to be recognized; first determining whether or not the image to be recognized exists based on the result of subjecting pixel density values of the input image in the mask area to operation for each image to be recognized; and second determining whether or not any of the plurality of images to be recognized exists in the window area based on the determination result of the first determining step.

Abstract: A color image recognition apparatus capable of judging whether an original is monochromatic or color comprises an image reader for rapidly scanning the original to develop image data and a color display coordinate system for converting the image data to luminance data and color difference data. A pixel color judging unit judges the color of each pixel based upon the luminance data and the color difference data, and a block color judging unit compares the number of color pixels with the number of black pixels contained in each of the plurality of blocks of pixels. An original color judging unit then counts the number of color blocks in the original to judge the color of the original.

Abstract: A digital filter capable of obtaining a filter output by adding the products of image data in a filter operation area with a set of desired filter constants, selecting a predetermined portion among the calculated bits with an output bit selection circuit, and expressing the result retrieved according to the decimal point format of the filter constants. According to the digital filter described above, different types of filter operations such as a low-pass filter operation and a high-pass filter operation can be performed accurately.