tron said:I can understand the improvement in noise when downsampling but can someone prove that downsampling an image (to 8Mpix for example) improves DR?
I ask this because I believe in practice what is burned in the highlights has been lost forever and when there are shadow areas I cannot image how a "dark" pixel will benefit from its neighbour equally dark ones.
Dynamic range is the number of stops between "saturation point" and blackpoint. Saturation point is where the highlights get "burned out". This doesn't change. Black point is the point at which SNR is 0db (that is, signal to noise ratio is 1). Downsampling reduces noise, so the SNR at what used to be the blackpoint goes up (to 5db for example) and the new blackpoint after downsampling is some way down from that.
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