On Mon, May 21, 2012 at 12:57 PM, Paul Hartman <paul.hartman+gen...@gmail.com> wrote: > On Mon, May 21, 2012 at 11:31 AM, Michael Mol <mike...@gmail.com> wrote: >> >> I'm seriously wondering if there might not be something broken with >> the .jpeg files I'm spitting out. That laptop (saffron) is in the >> middle of an overdue emerge --update --deep --newuse @world, though. >> (And I saw it was complaining about 19 blockers...) It may be overdue >> for a depclean and some other maintenance. I haven't tweaked things >> much, as it's my last functioning Gentoo box until I get kaylee and >> inara fixed. > > It looks like the file uses arithmetic coding, which has legal > restrictions (patents, licensing, blah), which means many jpeg > implementations do not support it. That probably is why it works in > some places and not in others. You should pretty much always use > Huffman coding instead of Arithmetic coding if you're using the images > on the internet or sharing them with others. The image quality is not > affected by this choice, only the way the data is stored in the file. > The file size will be slightly larger using Huffman, but in most cases > only barely larger.
I'm familiar with the difference between Huffman and arithmetic[1]. I don't recall seeing any options for managing it, though. I'd have to check to find out what USE flags I've got enabled that might be involved. Also surprising that Windows 7 won't process it. [1] Side effect of having a crazy compression geek for a friend and coworker. I think he finally got around to trying my suggestion of saving off the deflate window state for seekable .tar.gz files. -- :wq
