YDbDr是SECAM制式規格電視所采用的色彩空間。
1966年法国提出SECAM彩色电视制式,並制度YDbDr。
Y, Db和Dr訊號是產生自RGB 三原色。R, G和B的權重儲存於Y信号,所代表的是该点亮度.
RGB 色彩空间和YDbDr轉換之近似公式。
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從RGB至YDbDr:
![{\displaystyle Y=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/7f5ec90f224c20ef874332d97185f01168dbdcf0) |
![{\displaystyle 0.299R}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c78a9ca5f133f4f05d22d56c5995e49673272b31) |
![{\displaystyle +0.587G}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ae8e627adb3ca227700ec8630f1b3834e1cc0dec) |
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![{\displaystyle Db=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/336b4fcb58a46fc52332c360a2fde1a1b4c5c1f7) |
![{\displaystyle -0.450R}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ef140f3877e0e51f6f924ced878c801f786b54c7) |
![{\displaystyle -0.883G}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c897bea0a8ae09a4556678b14fdec9ac088d2744) |
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![{\displaystyle Dr=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/7e5e69591955f7e0949413249521cd64ae1a04fc) |
![{\displaystyle -1.333R}](https://wikimedia.org/api/rest_v1/media/math/render/svg/1c5a255976ae43d65685af4cdfc6355893997e9f) |
![{\displaystyle +1.116G}](https://wikimedia.org/api/rest_v1/media/math/render/svg/42cd029639e762cf61756ae7b61788b64f618ca8) |
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从YDbDr至RGB:
![{\displaystyle R=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e302251ceae37515baa64235baca2cc543dcccf3) |
![{\displaystyle Y}](https://wikimedia.org/api/rest_v1/media/math/render/svg/961d67d6b454b4df2301ac571808a3538b3a6d3f) |
![{\displaystyle +0.000092303716148Db}](https://wikimedia.org/api/rest_v1/media/math/render/svg/118822b1eddcae06618ea2404535268e2f261cf9) |
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![{\displaystyle G=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/eb05bfee3ea6feb86f0005a82945ce08939910be) |
![{\displaystyle Y}](https://wikimedia.org/api/rest_v1/media/math/render/svg/961d67d6b454b4df2301ac571808a3538b3a6d3f) |
![{\displaystyle -0.129132898890509Db}](https://wikimedia.org/api/rest_v1/media/math/render/svg/490f40b2d5e8fef91b893b3f1aff4d179f673332) |
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![{\displaystyle B=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3500d05a8f761313103968e3942c4ed235f88135) |
![{\displaystyle Y}](https://wikimedia.org/api/rest_v1/media/math/render/svg/961d67d6b454b4df2301ac571808a3538b3a6d3f) |
![{\displaystyle +0.664679059978955Db}](https://wikimedia.org/api/rest_v1/media/math/render/svg/72ec236817851b79a81091169627dc018e5875df) |
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或者:
你可能會發現YDbDr的Y分量等同於YUV的分量。Db和Dr也類似於U和V如下:
![{\displaystyle Db=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/336b4fcb58a46fc52332c360a2fde1a1b4c5c1f7) |
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![{\displaystyle Dr=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/7e5e69591955f7e0949413249521cd64ae1a04fc) |
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參考書目[编辑]
- Shi, Yun Q. and Sun, Huifang Image and Video Compression for Multimedia Engineering, CRC Press, 2000 ISBN 0-8493-3491-8