Author here. I am having some trouble reproducing the 2 seconds number, but with optimizations I'm getting around 1.5 seconds (without, I'm up to 5!), and as b

Author here. I am having some trouble reproducing the 2 seconds number, but with optimizations I'm getting around 1.5 seconds (without, I'm up to 5!), and as balducien mentions, /u/DroidLogician pointed out a _huge_ performance flaw in the file reading code. Writing bad code is easy in any language (as I just showed :) - writing _super_ performant code is only possible in some. EDIT: I made a pretty bad mistake while writing this comment, claiming that fixing the file reading code improved the speed of the decoder _a lot_, which was not true at all. In fact, the difference is barely (if at all) noticeable when decoding lena.jpeg. However, when reading a larger file, the improvement is definitely there. So sorry! Replying to HN comments while drinking and watching a movie turns out not to be a great idea after all :)