Detect scratches from an image with open CV?

See more:

C#

OpenCV

I have applied an effect to highlight all the edges on an image with C# wrapper to Image Magick called Magick. NET . I intend to detect the scratches and small circles on it. How can I do this. This is what I got so far, check the image from this imgur link

https://imgur.com/a/YlBcnCh

How can I isolate the small marks and scratches and draw a rectangle around them in the output image, thanks

What I have tried:

I have tried this code

using(var image = new MagickImage(imageFiles[0])){
  //detect the edges
  image.Edges(10);
  image.GaussianBlur(10);
  image.Write("temp.png");
  new PictureMagnifier("temp.png").ShowDialog() ;
  }