add support for png compression?

[cartazio]

Hey,
I'm noticing that the png encoder doesn't (as yet) do the line based filter type compression.

a) would code that enables support for richer png compression be something you'd welcome into the code base?

(at some point in the coming months, i'm planning on adding some sort of png raster backend for diagrams, and vector graphics are a class of images that png can compress really well, so its a natural choice)

b) since i'll be playing with writing lots of compression related algs over the coming months, theres a small chance I might get around to doing this myself (though no guarantees)

[Twinside]

a/ yes
b/ good, because I don't have time to do it myself :)

[nomeata]

I’d be a user wanting this. Any progress?

[Twinside]

the b/ (and a/ also) still hold, I've even less free time than before and I'm favoring other projects right now :-/

But I've at least thought a little about it, all the modifications has to be done here and there, instead of the zero : data, calling a function to implement the simple heuristic given in the png specification: the minimum sum of absolute difference should do the trick. And maybe a more complex loop to handle the paeth filtering.

[cartazio]

i may have some free time to do this some point during December as a break from my other OSS, please bump the thread early december and i'll do it for funsies :)

[Twinside]

Requested bump for @cartazio