Find similar images

Reverse image search utility based on perceptual hash algorithms

The perceptual hashes are calculated from reduced 8x8 grayscale images:

Algorithm	Description
Average	Use the pixel's value and the average color
Block	Divide image in blocks and use their mean value
Difference	Use the difference between adjacent pixels
Perceptive	Use a discrete cosine transform (DCT) and compare frequencies rather than color values

Find similar images can be built from source with the 'SimilarImages.sln' Visual Studio 2013 solution.

Install the NuGet package 'OpenCvSharp3-AnyCPU' https://github.com/shimat/opencvsharp

PM> Install-Package OpenCvSharp3-AnyCPU