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Y'CbCr (601) from R'G'B'
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$ X" w* N: h+ A$ d" wY' = 16 + ( 65.481 * R' + 128.553 * G' + 24.966 * B')
, o |9 p8 \9 X/ |) F: O7 yCb = 128 + (-37.797 * R' - 74.203 * G' + 112.0 * B')
: d. @: p4 c* p% f- PCr = 128 + (112.0 * R' - 93.786 * G' - 18.214 * B')
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R', G', B' in [0; 1]0 M C2 k; C6 ^ a& i' Y; G! e0 n
Y' in {16, 17, ..., 235}3 k: |' k ?9 |% h1 a
with footroom in {1, 2, ..., 15}
/ @2 l3 m" _4 |8 p0 o headroom in {236, 237, ..., 254}1 V% E. C: B8 ~( T: f& e
sync. in {0, 255}5 C2 C. v/ j) F3 j' s; |; i0 G
Cb, Cr in {16, 17, ..., 240}+ ]+ Z* B( R ^6 c5 w7 T
您說的128應該是指Cb Cr 的grayscale, 當RGB每channel輸入皆為0時Cb Cr 輸出128, Y 輸出16, 此時應該對應到RGB domain gray level的0, 這就是ADC的DC offset.$ p) G% n& ]5 d2 V- H
此時, 若Cb 或 Cb 輸出值為131表示輸出的Cb 或 Cr 相位有旋轉, 色度值非正確值* R: R& g5 h' X& S) I
您可以參考以下的網頁+ `- @0 S) H# D' R8 \8 O! U
http://en.wikipedia.org/wiki/Color_matrix0 Y$ A% f0 i. e" E
或是去找一些color matirx的書籍 |
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