There is a third possibility. A JPEG picture tile consists of a linear combination of 64 standard tiles. If you only compute a few of them you could display an approximation of the picture somewhat faster.

This is (if I understand it correctly) similar to the method in progressive encoding only that with this method you have to read in the whole file. With progressive encoding the coefficients of the standard tiles are grouped together so that you only have to read part of the file to display a first approximation of the picture.

That presumes that displaying the pictures is not completely IO-bound. Just tested it on my machine, konqueror showing only thumbnails of hundreds of pictures got to 72% CPU usage, so I think showing the full pictures could be stressing out the CPU.

In reply to Re^2: PerlMagick Fast Image Loading by jethro
in thread PerlMagick Fast Image Loading by renegadex

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.