An image processing system comprising an information processing apparatus directly operated by a user, a plurality of image forming apparatuses including at least two types of image forming apparatuses having different printing attributes, and an image processing apparatus for controlling said plurality of image forming apparatuses in response to a request from said information processing apparatus, said information processing apparatus, said plurality of image forming apparatuses, and said image processing apparatus being connected to each other, said image processing apparatus selecting at least one image forming apparatus from said plurality of image forming apparatuses, and outputting image data to the selected at least one image forming apparatus,
- wherein said image processing apparatus comprises input means for inputting a group of image data, distributing means for distributing the input group of image data depending on printing attributes of the group of image data, a plurality of image processing means for executing image processes corresponding respectively to printing attributes of the distributed image data, on the group of image data, selecting means for selecting at least two image forming apparatuses from said plurality of image forming apparatuses, which have printing attributes compatible with results of the execution of the image processes executed by said image processing means, and output means for outputting the image data on which said image processes have been executed, to the selected at least two image forming apparatuses,
- wherein said printing attributes comprise at least a first printing attribute, and a second printing attribute, and said image processing means comprises first and second image processing means for executing image processes depending said first printing attribute and said second printing attribute, respectively,
- wherein said image processing apparatus further comprises judging means for judging whether or not each of the image data of said group belongs to said first printing attribute after said first image processing means have executed the image process on all the image data of said group, and image process re-executing means for determining that each of the image data belongs to said second printing attribute and causing said second image processing means to again execute the image process on the each of the image data when a result of the judgment by said judging means is negative, and
- wherein said output means outputs the image data on which said image processes have been executed by said first image processing means and said second image processing means, to said selected at least two image forming apparatuses, respectively.