mogul wrote:
Thanks for the explanation Matt...if the Canon way of making much smaller files is better, why doesn\'t Sony use it?
Why indeed
mogul wrote:
There must be some trade offs.
Lossless compression results in variable filesizes and in the worst case can make files larger (though I don\'t think this will ever happen in practice with RAW files). Basically the amount of compression achieved depends on the content of the image.
Sony\'s lossy scheme always gives the same size files (actually they vary very slightly, due to the lossy compressed embedded thumbnail!) which is advantageous when designing buffers etc, you can more consistent performance.
Canon\'s lossless compression is far more computationally expensive than Sony\'s lossy scheme which only requires a few instructions and a very small buffer, however with Canon most of the heavy lifting can be done in hardware, as it uses the JPEG format which is well understood and has a load of dedicated hardware/code available for it.
Jun 12, 2015 at 10:01 AM
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