maxvipworld wrote:
亮度在於Digital Sensor內所接收光粒子的數量
不看顏色或者視為同一顏色,它可以變為同顏色的圖,以色塊來看
亮度取決於同一色塊上,有接收到光拉子的數量。
我提到這篇,但好像沒人看:
http://www.i-cubeinc.com/3D/3shotcm.shtml
...(恕刪)
看不太懂您描述的,不過我上一篇引用的下面這句英文,就是從您引述的http://www.i-cubeinc.com/3D/3shotcm.shtml來的呀!因此怎麼會沒人看呢?
我把我的意思補全,下面這句來自你引述的那篇:
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The red pixel(請順便注意這篇作者的pixel定義,也跟樓主不一樣) that the red ray fell onto, will very accurately record its intensity value
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Red pixel能記錄intensity,green/blue pixel也能記錄,因此:
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The green pixel that the green ray fell onto, will very accurately record its intensity value.
The blue pixel that the blue ray fell onto, will very accurately record its intensity value.
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也就是每個畫素,可獨立接收並將intensity記錄下來。如果還是很難理解,可以先將Bayer filter跟顏色忘掉,也就是:
===========================================================================
The pixel that the ray fell onto, will very accurately record its intensity value.
===========================================================================
而Luminance(亮度Y)定義為: Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction
因為這定義是物理通用的,不是單單針對CMOS感測器元件。套在CMOS感測器上,unit area就是每個單獨的R/G/B pixel。有4百萬個pixels,就會取樣到4百萬組含Luminance(亮度Y)資訊的資料。
以消費性手機拍照/錄影用到的JPEG/H.264來說,是採用YCbCr 4:2:0,不是RGB,也就是若有4百萬組亮度Y資料,Cb/Cr只要各1百萬組便可,以4Mp Bayer CMOS感測器的2百萬G畫素/1百萬R畫素/1百萬B畫素,來生成各1百萬的Cb/Cr,很夠用了。Bayer的假色問題,沒有人否認過,但業界的處理技術發展了幾十年,也已經很成熟了,並不會因此抹滅Bayer的價值,不然不會被如此廣泛採用。
如果覺得4百萬解析度的Y配上各1百萬的Cb/Cr,怎麼看都不對勁,那FullHD的消費性藍光影片或HDTV高畫質數位電視如日本衛星BS Digital,Y的解析度是1920x1080(*),Cb/Cr則都各只有960x540(*),重申一下:如果因為這樣,樓主前輩就要在地上打滾曰:「這不是1080p、這不是FullHD、這不是HDTV、這不是肯德基、你們都在騙人!!世人惟有我獨醒!!」,後進如我也只能甘拜下風.....
(*) 嚴謹來說,Y是1920x1088、Cb/Cr是960x544。