While there are plenty of free and commercial tools to remove duplicate files on the market it is hard to find a good dedicated duplicate image finder tool.
Differences between a duplicate file finder and a duplicate image finder
A general purpose duplicate file finder can help with the disk cleanup by identifying exact duplicate files. Unfortunately if images are stored in different file formats they can not be identified by an ordinary duplicate finder even if they look exactly the same. A dedicated duplicate image finder tool is needed in order to load and analyze the file data and compare it with the image that is stored in a different file format. A critical feature of an image finder is to be able to load as much as possible image formats. While the count of image formats is important it is useless without a good comparison algorithm. Most of these tools can identify just slightly re-sized or color-corrected images. A good tool for finding duplicate images should be able to identify a photo of the same subject in two completely different shots maybe even from different photo cameras.
How to test a duplicate image finder
Choosing the best duplicate image finder is not an easy task as most of the standard duplicate file finders are advertised as duplicate audio finder and duplicate image finder tools. Unfortunately this can not be easily checked and one should download and install a tool in order to determine if it is really capable of identifying similar items. How to make a quick test:
- Find 2 or more similar images
- Convert some of them to a different image format. Use for example a PNG and a JPG
- Use the tool to compare the images
- If it displays that the images are similar than it is capable of finding duplicate images
- An even better test is to compare two visually similar images
Which is the best duplicate image finder
The test above can be used to choose a duplicate image finder. Unfortunately there are hundreds of tools to be tested due to misleading advertising practices. Claiming a tool as the best is a subjective matter as one tool may be suitable for one user and not for another. In terms of performance and accuracy of results though, the leader is Visual Similarity Duplicate Image Finder (VSDIF) by MindGems Inc. It is a highly professional software the Corporate version of which is integrated in sock photography web sites, document management systems, healthcare applications. While the Corporate version cost $499 MindGems Inc. provides a low cost desktop version at just $24.95. MindGems Inc. provides also a duplicate music finder that works in a similar way and a free duplicate file finder.