from Hacker News

Loading pics from the middle

by metaprinter on 9/28/11, 2:13 PM with 1 comments

The DOM is great and all but I'm increasingly frustrated by slow loading of images on mobile devices. Can some smart person figure out how to load images starting from their center?

  • by sp332 on 9/28/11, 2:35 PM

    You could use "interlaced" or progressive images. (I don't mean scanlines like old TV signals.) GIF, PNG, and JPG use the same idea: it sends stores the pixels out of order, and progressively fills in the image all over instead of from the top down.

    Interlaced GIFs use a three-pass system. Interlaced PNGs use a 7-pass algorithm. Progressive JPGs actually decompose the frequencies and send the "most important" ones first. http://www.libpng.org/pub/png/book/chapter08.html#png.ch08.d...