clc; clear all; close all;// 변수를 초기화 한다.

ycbcr = rgb2ycbcr(imread('foreman_cif_0000.bmp'));// RGB를 YBCR 체계로 바꿔서 그림을 분석한다.

Y = double(ycbcr(:,:,1));// Y

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mask = [1 1 1 1 0 0 0 0

1 1 1 0 0 0 0 0

1 1 0 0 0 0 0 0

1 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0];//

Q = [16 11 10 16 24 40 51 61

12 12 14 19 26 58 60 55

14 13 16 24 40 57 69 56

14 17 22 29 51 87 80 62

18 22 37 56 68 109 103 77

24 35 55 64 81 104 113 92

49 64 78 87 103 121 120 101

72 92 95 98 112 100 103 99];//

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for i=1:8:288

for j=1:8:352

dct_Y(i:i+7,j:j+7) = mask.*(round(dct2(Y(i:i+7,j:j+7)-128)./Q));//

end

end

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for i=1:8:288

for j=1:8:352

idct_Y(i:i+7,j:j+7) = idct2(dct_Y(i:i+7,j:j+7).*Q)+128;//

end

end

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imshow(uint8(Y)) %1

figure,imshow(uint8(idct_Y)) %2

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D = uint8(Y) - uint8(uint8(idct_Y));

figure, imshow(D);

sum(sum(D))/(352*288)

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