Question

Given the quantization table as follows: 11 11 13 1517 15 17 23 25 19 21 25 33 The DCT coefficients of one 4x4 block is as follows: 20 1 4 -4 8 -10 -7 -8 -11 12 -11 Please fill the following table with quantized coefficients:

Answer 1

The quantized coefficients at index i,j of table with quantization coefficients

= (value at (i,j)of the DCT coefficient table) / (value at (i,j) of quantization table)  

so the table with quantization coefficients is below:

(20/9) = 2.2222	(14/11) = 1.2727	(-4/15) = -0.2667	(8/19) = 0.4210
(-14/11) = -1.2727	(-7/`13) = -0.5385	(11/17) = 0.6470	(-9/21) = -0.4286
(6/15) = 0.4	(-10/17) = -0.5882	(-7/23) = -0.3043	(-11/25) = -0.44
(-11/19) = -0.5789	(9/21) = 0.4285	(-8/25) = -0.32	(12/33) = 0.3636

the quantization coefficient table holds the nearest integer values of (value at (i,j)of the DCT coefficient table) / (value at (i,j) of quantization table) so we round off the values in table above to nearest integer value

2	1	0	0
-1	-1	1	0
0	-1	0	0
-1	0	0	0

.