Pixel Binning: Effect on SNR for Hardware vs. Software Binning Is there a difference in SNR (or any other measure of image quality) between using 2x2 pixel binning in the camera and shrinking the full resolution image in software (cv::INTER_AREA) to the same size (w/2, h/2) ?

I imagine that SNR is higher with binning if pixel binning is done "in hardware" but I'm not sure how binning is actually implemented or if it does make a difference, to what extent the difference is measurable/negligible.
If you have access to the raw pixel data, you can implement binning in software too. They should be identical upto the step-size of the ADC, by which the quantized analog sum of pixels may differ from sum of quantized pixels.

Hardware binning has the advantage that it has to transfer less number of pixels, hence can operate at high fps compared to raw data transfer.