The present invention enables a pattern identifying apparatus that calculates a feature amount and identifies a predetermined pattern, such as a face, based on the calculated feature amount to perform processing for reading a large volume of data at a high speed. To achieve this, a coprime relationship is established between an interval between adjoining processing windows arranged in an image and the number of memories in which the image is interleaved and stored, thereby always establishing an exclusive relationship between the memories from which data at the same position relative to reference points in the respective processing windows is read. It is thus possible to read data simultaneously, resulting in achievement of speedup.