Quoting "M. Adam Davis" : > On 8/5/08, Olin Lathrop wrote: >> Spehro Pefhany wrote: >> >> HD video is 1920 x 1080 pixels >> >> per frame, which is 2.1 Mbyte. >> > >> > With no compression or chroma subsampling there are 3 bytes per pixel. >> >> Oops, you're right. However 8 bits per color per pixel is highly optimistic >> color resolution. The actual uncompressed information is probably somewhere >> closer to 12 bits/pixel, but I don't have any solid evidence to support >> that. > > That would suprise me greatly - I would expect experts to complain > long and loudly if the camcorder only recorded 4096 colors - that > should be readily detectable by eye. > > However, I can't seem to find any specific mention of color > information on the canon website or the manual. I would be surprised > if the Digic II processor reads anything less than 24 bits per pixel > off the CCD, but perhaps someone can take apart the mp4 encoded stream > and tell us what the encoded color space really looks like. > > -Adam Human vision is significantly less sensitive to chroma (color) detail than to luminance (brightness) detail. This is taken advantage of in analog television signals,first developed in the 1950s, where the chroma bandwidth is but a fraction of the luminance bandwidth, and in digital video where the chroma signal is sampled at something like 1/4 of the resolution of the luminance information. But that's a form of (lossy) compression. What actually happens at the sensor is another kettle of fish again: http://en.wikipedia.org/wiki/Bayer_filter Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" s...@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist