Abstract: A new image watermark algorithm against rotation is proposed.This algorithm adds a datum line in the high frequency detail image in the wavelet domain.When the watermark extracted hough transform is used to detect the datum line and estimate the rotation angle.According to the angle,the original coordinate in the rotation image is searched for through coordinate transform to get the pixel.Getting the non-insert pixels from the original image enables a nearly lossless restoration of image and ext...

Key words: coordinate transform； wavelet transform； hough transform； image watermark algorithm；