The 2D Discrete Cosine Transform Type II

The discrete cosine transform is a transform that expresses a signal as a sum of cosine waves of various amplitudes and frequences. Invented by Kamisetty R. Rao and Nasir Ahmed in 1974, the discrete cosine transform has many practical applications in computer science, such as data compression in MP3 and JPEG. The JPEG standard implements 2D DCT-II to compress 8x8 macroblocks that the image has been divided into. This program applies the 2D-DCT-II on a greyscale image, and offers custom 8x8 pixel values, and quantization coefficients. An upscaled 8x8 DCT-generated image preview is also provided.