Howtosignalprocessing
- What is quantization in DCT?
- What is DCT in JPEG?
- What encoding does JPEG use?
- What is quantization table in JPEG?
What is quantization in DCT?
Quantization is the process of reducing the number of bits needed to store an integer value by reducing the precision of the integer. Given a matrix of DCT coefficients, we can generally reduce the precision of the coefficients more and more as we move away from the DC coefficient.
What is DCT in JPEG?
DCT is used in the JPEG image compression algorithm. The input image is divided into 8-by-8 or 16-by-16 blocks, and the two-dimensional DCT is computed for each block. The DCT coefficients are then quantized, coded, and transmitted.
What encoding does JPEG use?
Although a JPEG file can be encoded in various ways, most commonly it is done with JFIF encoding.
What is quantization table in JPEG?
The quantization table is stored in the header of the JPEG file to allow for decoding. For each quality factor, there are two associated Q-tables, one for the luminance channel and the second one for the chroma components. In this work, we focus on the luminance channel.
