Comparing images during upload

[sard]

There is desktop software that can compare images, (probably their histograms) and shows duplicate pictures with percentage of similarity. It will be great feature when user upload images can show is there are already uploaded similar images. I now that is not easy but with such funcktion coppermine gallery will represent itself like leader in on-line galleries.

[Joachim Müller]

Desktop applications are capable of that, but they need very long time to accomplish that (i.e. process all the images). On a webserver, this is even more critical, with shared resources and unpredictable server timeouts. This being said: nice suggestion, I can see the point, but I strongly doubt that this will be implemented in the future into coppermine's core.

[sard]

Probably there is are possibility to convert histogram value into specific number value that can be compared by similarity. So beside other information for image in database will be stored histogram number (decimal) created during upload. When new images are uploaded with valuated histogram number then should search the closest number and show associated image. This second part searching is easy, valuation of the image is harder part. Harder part can be done on the user computer, not by gallery hosting server.
Some cooperative work of software companies that create such software with coppermine team could create this unique, and practical feature.

[Joachim Müller]

Could be implemented as a plugin then, as I don't see the need for such a feature for most users.

[Αndré]

Afaik somebody is already working on a plugin that compares images by histogram and shows similar images.

[sard]

Could be implemented as a plugin then, as I don't see the need for such a feature for most users.

Almost every gallery with a lot of images has a problem with duplicates. More number of users that are uploading, there is more duplicates of the same images.  When the user upload, there will be very useful to know that image is already in the gallery. This is essentially needful and can convince many people to use gallery with such feature.

[sard]

Afaik somebody is already working on a plugin that compares images by histogram and shows similar images.

I'am glad to read that.