Image Copy Detection with Rotating Tolerance

In 2003, Kim applied DCT technique to propose a content-based image copy detection method. He successfully detected the copies with or without modifications, and his method is the first that can detect the copies with water coloring and twirling modifications. However, Kim’s method can only detect copies modified with a 180 degree rotation. When copies are rotated by 90 or 270 degrees, Kim’s method fails to discover them. Also, his method can not deal with the copies with minor rotations like 1 degree or 5 degree rotation, and so on. To conquer this weakness, we apply ellipse track division strategy to extract the features and propose our methods. The experimental results confirm that our proposed method can successfully capture block features of an image even if it is rotated to any degree.