1. An image processing system comprising: a first image processor equipped with an image input function; and a second image processor equipped with an image output function, wherein both of said first image processor and said second image processor can transfer image data to each other, and comprise image processing means for performing predetermined image processing on said image data using photographing information when photographing to acquire said image data, and at least one of said first image processor and said second image processor comprises means for determining the sharing of preprocessing and said predetermined image processing between said first image processor and said second image processor, and wherein the means for determining the sharing of said preprocessing and said predetermined image processing allocates said preprocessing, red-eye detection and red-eye correction between said first image processor and said second image processor on a basis of a throughput and state of said first image processor and said second image processor.