How to compare images of different sizes

Question

I have a problem comparing two identical images. if the image sizes are the same, then you can compare (without problems), if the sizes are different, then I can not compare. I compare pixel by pixel.

Is there a way in C # .net to compare similar images, for example, about 70%.

thanks

Laxman

Answer 1

You need to calculate and compare the perceptual hash of both images.

Read the following article and submit it to C # https://www.memonic.com/user/aengus/folder/coding/id/1qVeq

OR

You can use the AForge Exhaustive Compliance Pattern to calculate image affinities

The class can also be used to get the level of similarity between two images of the same size, which can be useful for getting information about how different / similar images are:

Answer 2

Use a Gaussian filter and resize the larger one to a smaller size, then use a Gaussian filter on a smaller one, and then try to compare them. The color ratios will not change too much, you can also use this if you do not want to change their size. You can find the pyramid detection function. I hope this can help. http://en.wikipedia.org/wiki/Pyramid_ (image_processing)