Comment by hhmc

The code on the right feels in mildly bad faith to me.

  - consts are dropped
  - variable definitions are merged onto multiple lines
  - usefully named constants like `nPixels`, `nBytes` are elided
  - the `idx` lambda is inlined

The net effect, for an initial skim, is that the code on the right looks terser and simpler. But in reality many of the "short cuts" hurt the long term quality of the code.