This paper develops a methodology for resizing image resolutions in an arbitrary orthogonal block transform domain. To accomplish this, we represent the procedures resizing images in an orthogonal transform domain in the form of matrix multiplications from which the matrix scaling the image resolutions is produce. The experiments showed that the proposed method produces reliable performance without increasing the computational complexity, compared to conventional methods when applied to various transforms.

In this paper, we propose a method of resizing images in the integer DCT domain employed by H.264/AVC. To accomplish this, we first derive the matrix scaling the image resolution, and then factorize the scaled DCT blocks and the post scaling factors (PF) from the matrix obtained from the multiplication of the scaling matrix and the original integer DCT blocks. Then, we separate the scaled DCT blocks into the integer scaling matrix and the scaled integer DCT blocks. The experiments show that the proposed method produces nearly the same performance as those operating in the real DCT domain.