An overview of the Geo-DefakeHop method, where the input is an image tile and the output is a binary decision on whether the input is an authentic or a fake one. First, each input title is partitioned into non-overlapping blocks of dimension 16 × 16 × 3. Second, each block goes through one PixelHop or multiple PixelHops, each of which yields 3D tensor responses of dimension H × W × C. Third, for each PixelHop, an XGBoost classifier is applied to spatial samples of each channel to generate channel-wise (c/w) soft decision scores and a set of discriminant channels are selected accordingly. Last, all block decision scores are ensembled to generate the final decision of the image tile.