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Y'CbCr (601) from R'G'B'
6 ]0 p; R) ?* c8 h9 z% s========================================================
M' W' ?/ P7 _$ p4 hY' = 16 + ( 65.481 * R' + 128.553 * G' + 24.966 * B')8 G4 y# D2 N* |
Cb = 128 + (-37.797 * R' - 74.203 * G' + 112.0 * B')
, S* C8 A0 H9 q' M* TCr = 128 + (112.0 * R' - 93.786 * G' - 18.214 * B')
! r/ B/ D# E9 n, B( N........................................................4 [. W" `# |9 W! J [
R', G', B' in [0; 1]1 R- I: e* e# F$ H7 |" m# n) a9 q
Y' in {16, 17, ..., 235}
0 V6 d, t6 _4 A; R4 H$ g with footroom in {1, 2, ..., 15}+ z' s6 K8 B3 ]7 d( v4 F
headroom in {236, 237, ..., 254}
& u4 A( c7 K- k: n4 Z& w. m" b sync. in {0, 255}
, {/ K% v, {" L3 y$ nCb, Cr in {16, 17, ..., 240}; J/ { v, e! }
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.
4 |7 |- z; `$ ^4 \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. k( @7 y: k2 g, u) q
您可以參考以下的網頁
" U! m: [/ t$ Y" a1 vhttp://en.wikipedia.org/wiki/Color_matrix1 s- H" ]2 D, K- {
或是去找一些color matirx的書籍 |
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