Achal
On 4/28/05, Achal Pashine <achalpashine@xxxxxxxxx> wrote:
On 4/28/05, Terry <terry@xxxxxxxxxxxxxxxxxxxx> wrote:I don't think this is correct, RAW files are not compressed from what I understand, they are just that RAW, the reason they are smaller then say TIFF files is because they have not had any of the color information applied to them, I cant remember the exact term but anyway if you could see a raw file as it exists it would be in a gray scale with no white balance applied to it, when you open a RAW file
I think, what Greg says makes sense. The data can be compressed to save like zip. Just removing the gaps rather than the information content.
As far as I understood (from reading only, no formal course), RAW files stored the numerical value of the photon driven-voltage generated at each pixel (seperate for for 3 primary colors?). Which then needs to be linearlized using the Bayer transformation to translate into an actual image file (which is further compressed in jpeg conversion). The bit depth of the information in RAW format depends on the levels of variables that can be stored for each pixel (16 bit may have 2 to the power of 16 levels of brightness values etc.) For my lack of taking a formal digital photography course, I was at a loss to understand when Emily suggested that RAW is a "compression".
Achal
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Achal Pashine
achalpashine.blogspot.com
