
How JPG Works - dr_linux
https://medium.freecodecamp.com/how-jpg-works-a4dbd2316f35#.bulg3aijd
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cma
> This example shows a commonly used matrix of quantization factors , one for
> each basis image

Key point here that isn't spelled out in the text is that the low frequency
stuff (top left) is weighted higher than high frequency stuff. After dividing
by the quantization factora and rounding, most high frequency stuff rounds to
zero (which is mentioned, it just wasn't spelled out). Higher quality levels
don't have as large of factors there and preserve high frequency data.

(Edit: just got to where gets detailed later in the quality section, but still
feel it should be mentioned where that matrix is first shown)

