1. A method of processing images containing a blotch, the method comprising: accessing one or more component images of a target image, the target image including a first component image and a second component image; accessing one or more component images of a reference image, the reference image including a first component image and a second component image; determining a motion vector characterizing motion between the target image and the reference image; comparing, based on motion indicated by the motion vector, the first component image of the target image with the first component image of the reference image to produce a first-component comparison result; comparing, based on motion indicated by the motion vector, the second component image of the target image with the second component image of the reference image to produce a second-component comparison result; and determining that the first component image of the target image includes a blotch based on the first-component comparison result and the second-component comparison result.