If you're doing interpolation you probably don't want a linear colourspace. At least not linear in the way that light works. Interpolation minimizes deviations in the colourspace you're in, so you want it to be somewhat perceptual to get it right.
Of course if you're not interpolating but downscaling the image (which isn't really an interpolation, the value at a particular position in the image does not remain the same) then you do want a linear colourspace to avoid brightening / darkening details, but you need a perceptual colourspace to minimize ringing etc. It's an interesting puzzle.
Of course if you're not interpolating but downscaling the image (which isn't really an interpolation, the value at a particular position in the image does not remain the same) then you do want a linear colourspace to avoid brightening / darkening details, but you need a perceptual colourspace to minimize ringing etc. It's an interesting puzzle.