1. A system for detecting duplicate images, the system comprising: a computer apparatus including a processor and a memory; and a duplicate detection software module stored in the memory, comprising executable instructions that when executed by the processor cause the processor to: receive multiple images; determine that first and second images of the multiple images have similar key attributes; retrieve a document template associated with the first and second images; superimpose the first and the second images over the document template; compare the first image with the second image and the document template; identify differences between the first image and the second image relative to the document template, the differences comprising a portion of the first image containing first markings and a portion of the second image containing second markings; determine that the portion of the first image and the portion of the second image are positioned in different and separate areas of each of the first and second images, wherein the first markings and the second markings are identical; and discard at least one of the first image and second image based on one or more sources of the first image and the second image, image quality of the first image and the second image, or receipt date of the first image and the second image.