1. An image processing apparatus comprising: a processing means for obtaining a processed image data set by performing further image processing on an image data set, on which image processing has been performed according to an image processing mode set at a photography device and to which supplementary information including image processing information indicating the image processing mode has been attached; an intention judgment means for judging whether an image processing mode of a processing object image data set has been intentionally set, based on supplementary information of the processing object image data set and supplementary information attached to at least one of image data sets, which were obtained before or after photography time of the processing object image data set, wherein the at least one of image data sets includes an image data set obtained immediately before obtainment of the processing object image data set; an undoing means for undoing the image processing which has been performed on the processing object image data set if the judgment by the intention judgment means is NO; and a control means for controlling the processing means so that the processing means performs the further image processing on the processing object image data set, of which image processing has been undone by the undoing means, wherein the intention judgment means judges whether the image processing mode of the processing object image data set and an image processing mode of the image data set obtained immediately before obtainment of the processing object image data set are the same, wherein if the judgment is YES, the intention judgment means further judges whether an obtainment location of the processing object image data set and an obtainment location of the image data set obtained immediately before obtainment of the processing object image data set are within a predetermined distance based on photography location information included in the supplementary information attached to the processing object image data set and photography location information included in the supplementary information attached to the image data set which was obtained immediately before obtainment of the processing object image data set, wherein if the further judgment is YES, the intention judgment means judges that the image processing mode of the processing object image data set has been intentionally set.