Quantizer and method optimized for DCT AC coefficients

摘要

The present invention relates to a quantizer and a method optimized for a DCT AC coefficient, and more particularly to a quantizer and a method for determining a step size corresponding to a number of quantization bits assigned to a DCT AC coefficient; A search unit 200 connected to a signal output terminal of the step size determining unit 100 and searching for a decision level interval to which a DCT AC coefficient value belongs; And a restoration level generator 300 which is in contact with the signal output terminal of the search unit 200 and outputs a restoration level Xq (quantized value) which is an intermediate value of a decision level found by the search unit 200 .;Since the present invention is designed such that the DCT AC coefficient having the Laplacian distribution is input and the crystal level is optimized to the Laplacian distribution, it is easy to implement the quantizer because the crystal level is uniform and the restoration level is expressed as an intermediate value of the determination level In addition, since the calculation for quantization is simple, the quantization time can be reduced.