To provide a learning method and a pattern recognition method and device for realizing stable pattern recognition with the combination of a whole part or part of spatial differential quantity on an input image as featured values even in contrast change.

This pattern recognition device is provided with a featured value extracting part 12 for extracting spatial differential quantity as featured values from learning data and a featured value compounding part 31 for constant-multiplying the extracted featured values, and for compounding the featured values in contrast change. The combination of the featured values extracted by the featured value extracting part 12 with the featured values compounded by the featured value compounding part 31 is defined as learning data, and a model (learning result) for pattern recognition is obtained by learning in a learning part 32.

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