Images from checks may be compared with each other to detect a twice-deposited or represented check. An image of a check may be parsed into regions or tiles, for example. In an implementation, values for regions or tiles over a predetermined area (e.g., an area from a character in the magnetic ink character recognition (MICR) line at the bottom of the check to the dollar sign symbol) may be compared. In an implementation, a virtual overlay of two check images may be performed and a correlation may be determined.