RGB Codecs sample each base color, with no Chroma subsampling.
Ex. ProRes4444, HDCAM SR Dual Link.
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Y'CbCr Codecs use Luma sampling + Chroma subsampling.
Vertical and Horizontal resolution is indicated by the last two numerals:
4.4.4 use uncompressed Chroma subsampling
4.2.2 use compressed, (1/2 vertical and 1/2 horizontal resolution) Chroma subsampling (Ex. ProResHQ, ProRes422, ProResLT, ProResProxy, ACV-Intra 100, XDCam422, Canon MXF422, DVCProHD and DVCPro50, DBeta)
Prosumer also use 4.2.0 (HDV, AVCHD, AVC-Intra 50, DVCam PAL, Mpeg2-DVD) or 4.1.1 variants (DV, DVCPro, DVCam NTSC)
Reduced Chroma subsampling makes smaller file sizes = More storage efficiency, but creates image artifacts (halo, color bleeding/smudging on edges.)
BIT DEPTH
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8 bit Codecs are 24 bits image files.
RGB 8 bits for each base color, intensity range: [0-255].
A pixel that's [0,0,0] is black, a pixel that's [255, 255, 255] is white.
Y',Cb,Cr has a different intensity range [16-235] to allow for super white/black.
Limited range problematic especially for gradients (stepping.)
Ex. 8 bit Codecs:
Uncompressed 8bit, HDV, DBeta, ProResProxy, DV, DVCPro, DVCam, Mpeg2.
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10 bit Codecs are 32 bits image files = 10 bits for each base color (RGB) +2 spare bits. Intensity range: [0-1023]
Y',Cb,Cr has a different intensity range [64-940] to allow for super white/black.
Uncompressed 10bit, ProRes4444, ProResHQ, ProRes422, ProResLT, AVC-Intra 100, Canon MXF422.
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10 bit LOG (Cineon, DPX) is equivalent to 12 bit Linear, but values are Log-curve compressed to match the film emulsion sensitivity to light which is logarithmic. This allows for a wider dynamic range by rolling-off the highlights that would be otherwise clipped in 8, 10, even 16 bit linear capture. Film print density range higher than 1080 values
Intensity range: [0-?] for each color. (Eq. 12 ƒ-stops.) Ex. Film scans.
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12 bit Codecs
Intensity range: [0-?] for each color. Ex. RED One.
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16 bit Codec are 48 bits image files.
Intensity range: [0-65535] for each color.
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Floating point is only for processing images, not storage. Better, more precise maths for calculation = higher quality results. Intensity range: [?-?] (Eq. 25 ƒ-stops.)
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ACES "unlimited" (Eq. 30 ƒ-stops.)
