AForge.NET在两个图像中比较并查找Blob（连接的组件）

Question

I want to use AForge.NET library to examine similiar images and to localize the differences. I can imagine the following algorithm.

a. Compare 2 images, generate as result binary image with white pixels for differences and black pixels for matches.

b. Use BlobCounter for searching of the connected pixels.

What filter can be used for a)? How to count the pixels in each Blob ?

Answer 1

Take a look at my previous answer here Aforge Blob Detection

For A), you can use the ThresholdDifference, this will give you black pixels when there are no changes and white pixels when there is a difference. You can invert this with a Image>Invert ( http://www.aforgenet.com/framework/docs/html/458e1304-0858-ae29-113f-e2ec9072c626.htm )

As for B), you can use Connected Component Labeling (see the post), this will give an approximate width and height of the objects. If you want count exactly how many pixels are different you will probably need to write an procedure for this. It is not very difficult, it is just a two nested For cycle that will go over each X, Y pixel and then will increase a counter every time it finds an specific color on it.