Optimal approximation of uniformly rotated images: relationship between Karhunen-Loeve expansion and discrete cosine transform
Michihiro Uenohara, Takeo Kanade · IEEE Transactions on Image Processing · 1998
We present the concept that for uniformly rotated images, the optimal approximation of the images can be obtained by computing the basis vectors for the discrete cosine transform (DCT) of the original image in polar coordinates, and that the images can be represented as linear combinations of the basis vectors.