News for hackers. Stuff that matters.

A comment on Sharing learnings about our image cropping algorithm. Parent comment

Re:Sharing learnings about our image cropping algorithm by jedberg on Wednesday May 19, 2021 @04:51PM (#27214321)
Here is the code:

https://github.com/reddit-archive/reddit/blob/753b17407e9a9d...

But in short, it's a histogram of the values of the pixels.

[ Parent | on HN ]
Re:Sharing learnings about our image cropping algorithm by andbberger on Wednesday May 19, 2021 @07:25PM (#27215707)
Which is not really image entropy at all, as it totally neglects spatial structure. You could sort an image and get the same entropy using the histogram approach.
[ Parent | on HN ]
Re:Sharing learnings about our image cropping algorithm by bavell on Wednesday May 19, 2021 @06:47PM (#27215494)
"Entropy" in this context also left me wondering. Perhaps "variance" or "deviation from the mean"?

Thanks for the insights!

[ Parent | on HN ]
Re:Sharing learnings about our image cropping algorithm by MauranKilom on Wednesday May 19, 2021 @07:29PM (#27215731)
Entropy usually boils down to "sum p * log(p) for all p (and possibly normalize)", assuming you have discrete probabilities p. It is not related to variance or mean.
[ Parent | on HN ]