What can I use to find similar photos?
Q
Can you recommend a tool that identifies similar photos in my collection. It spans 55 years and all have been scanned in. Perhaps one that creates an MD5 hash of the original, then scans for similar hashes? Andy Newton
A
An MD5 hash (a unique 32-character string generated using the contents of a file) is useful when locating identical photos, but not similar ones. Edit just a single pixel in a photo and it will generate a completely different hash. However, there are tools to help you find similar photos. Before trying these, be aware that running searches on collections as large as yours can take a long time, and you may find they return lots of photos that have nothing in common.
One option is Find.same.images.ok ( www. snipca.com/35189 – the Download button is under the screenshot at the top left). Once it’s open, click the Compare All button (centreleft), then select ‘Folder vs. Folder’. Next, create a new folder on your PC and copy your source photo to it. Click the ‘...+’ button just under the Start button and navigate to this folder, then click the ‘...+’ button on the far right and navigate to your photo library. Next, click the Similarity option to set it to a value other than 100 per cent (which would only find exact duplicates). Click Start. Once the search has finished, click any of the results to view the results in the preview window at the top.
If this doesn’t provide satisfactory results, try imgseek ( www.snipca.com/35190), which hasn’t been updated in years, but still works well. Click the Add tab, then the ‘...’ button, select the folder you want to search for similar photos, then click Add (it might take a while for imgseek to index your photos, but it only needs to do this once). Next, click the Search tab, then the ‘...’ button next to the black box and select your source photo. In the box below, choose how many results you want to see, then click the magnifying-glass button. The similarity percentage will be shown under each thumbnail (see screenshot).