1. An image processing system which processes images obtained in series at different time points by capturing a recognition object, comprising: a memory; an image input unit configured to store the images in the memory; a recognition object condition judging portion configured to determine whether or not the recognition object existing in each of the images is recognizable in accordance with a preset determination condition; a recognition object detecting portion configured to detect image areas of the recognition object determined as recognizable by the recognition object condition judging portion; a movement detecting portion configured to detect a movement amount of the recognition object based on the images stored in the memory; a sub-area detecting portion configured to detect sub-areas to be recognized respectively in the image areas of the recognition object read out from the memory, in accordance with the movement amount of the recognition object detected by the movement amount detecting portion; a recognition portion configured to perform recognition processing on the sub-areas detected by the sub-area detecting portion and to store recognized characters and/or recognized patterns and the corresponding reliabilities into the memory as recognition results for the sub-areas, respectively; and a recognition result integration portion configured to read out the recognition results for respective sub-areas from the memory, to integrate the recognition results in the light of the reliabilities, and to output an integrated result.