## dct

### Video Compression: What is discrete cosine transform?

I've implemented an image/video transformation technique called discrete cosine transform. This technique is used in MPEG video encoding. I based my algorithm on the ideas presented at the following URL: http://vsr.informatik.tu-chemnitz.de/~jan/MPEG/HTML/mpeg_tech.html Now I can transform an 8x8 section of a black and white image, s...

### Query on Discrete Cosine Transform(DCT)

Hello, I am doing some basic Matlab simulations on DCT used in Video Compression. I have following questions arised out of that: 1.) In a 16x16 MB , if one does a 8x8 size block DCT (4-times) for that MB in first case and a one shot 16x16 size block DCT in second case, Will the reconstructed block at the decoder will have same/similar ...

### Need help on BMP to JPEG conversion

I'm writing a C++ program to convert a BMP image into a JPEG. Here's the basic algorithm I'm trying to follow: Convert RGB color space to Y,Cb,Cr.. Down sample Cb and Cr by 2 (that means for each square block of 2*2 there is 4 different Y value but 1 Cb and 1 Cr value Apply DCT to data units of each 8*8 pixels... Then apply quantizati...

### DCT Compression - Block Size, Choosing Coefficients

I'm trying to understand the effect of the Block Size and best strategy of choosing the Coefficients in DCT compression. Basically I want to ask what I wrote here: http://stackoverflow.com/questions/4582/video-compression-what-is-discrete-cosine-transform/1948138#1948138 Lets assume the most primitive compression. Making block of an im...