EqImage is a project of comparison of pictures. It is available as a free Web
Service.
CBIR (Content-Based Image Retrieval) is a way to index images or find a
similarity between images. There are lot of methods to be used as engine in
CBIR system.
The method I use is based on image transformation into it's frequency domain.
There are 3 steps:
-
Load each image and store them ;
-
Generate their signature using Fourier Transform: images must have same size
and same colour (grayscale transformation);
-
Compare their signature using Euclidean distance. The smaller the distance the
image will get more similar (0 means images are identical).
Main problems comparing images on the web are pertinence and performance.
Comparison must be fast and give exact results.
It can be useful for search engines, copyrights checking and so on...
This Web Service is developed in C# language.