Abstract: An image processor (14) in a photocopier (10) takes composite input image (20a) that includes a plurality of skewed sub-images (22a, 24a, and 26a). It revises the image so as to produce an output composite image (20b) containing aligned sub-images (22b, 24b, and 26b). To identify the input image's sub-images, the image processor (14) identifies connected groups (44, 48 and 54) of pixels that meet certain criteria, and it eliminates from consideration each group (48) whose bounding box (50) is included within the bounding box (46) of another connected group (44). Skew angles for the different sub-images are determined by finding the best-fit lines through the outline pixels of their respective connected groups, and the sub-images are de-skewed by the negatives of those lines' angles.