Patent ID: 8582136

Claim:
An image processing apparatus comprising: a reader that reads an image on a document; an output portion that outputs image data read out from the document by the reader; a detector that detects a plurality of first key information pieces collectively embedded on one side of one sheet of the document from which image data is read out by the reader, and a second key information piece to be compared to the first key information piece; wherein the second key information piece is embedded on the other side thereof or on another sheet of the document; a comparator that compares the plurality of first key information pieces and the second key information piece detected by the detector, and judges whether or not one of the plurality of first key information pieces and the second key information piece are coincident to each other; wherein when the comparator judges the one of the plurality of first key information pieces and the second key information piece are coincident to each other, the comparator determines that the one of the plurality of first key information pieces and the second key information piece are related to each other; and a controller that permits the output portion to output image data read out from all relativity judgment target sheets of the document, if the comparator determines about all these respective sheets that the one of the plurality of first key information pieces and the second key information piece are related to each other, and prohibits the output portion from outputting image data read out from at least one sheet of the document, if the comparator determines that the one of the plurality of first key information pieces embedded on the at least one sheet of the document and the second key information piece to be compared to the plurality of first key information pieces are not related to each other.