ARSD PNG memory usage

[thedeemon via Digitalmars-d-learn]

On Friday, 17 June 2016 at 01:51:41 UTC, Joerg Joergonson wrote:
> Hi, so, do you have any idea why when I load an image with 
> png.d it takes a ton of memory?

I've bumped into this previously. It allocates a lot of temporary 
arrays for decoded chunks of data, and I managed to reduce those 
allocations a bit, here's the version I used:
http://stuff.thedeemon.com/png.d
(last changed Oct 2014, so may need some tweaks today)

But most of allocations are really caused by using std.zlib. This 
thing creates tons of temporary arrays/slices and they are not 
collected well by the GC. To deal with that I had to use GC 
arenas for each PNG file I decode. This way all the junk created 
during PNG decoding is eliminated completely after the decoding 
ends. See gcarena module here:
https://bitbucket.org/infognition/dstuff
You may see Adam's PNG reader was really the source of motivation 
for it. ;)