To Rotate an Image without much changes in its Pixels

Question

I am doing a project on Image Watermarking using Discrete Wavelet Transform. I have done with watermarked image,Now I am attacking image with attack like rotation. My question is that when I apply function imrotate to the watermarked image, all the pixels that are not included in the rotated image becomes zero as it is property of imrotate. Due to this I got very low PSNR between Original Image and rotated Watermarked image.

My question is-I want to rotate the image but also need to have high value of PSNR after rotation. Is there any method that after rotation all or most pixels of rotated image resembles with pixels of original image.

Shortcoming of imrotate ie zero value of pixels outside rotated area can be removed by which method???????????????

Answer 1

For imrotate, specify bbox = "crop," so that the output image is the same size as the input image. (Reference: https://www.mathworks.com/help/images/ref/imrotate.html)