Hello Anonymous Monk,

GD uses png compression.

> The optional $compression_level argument controls the amount of compression to apply to the output PNG image. Values range from 0-9, where 0 means no compression (largest files, highest quality) and 9 means maximum compression (smallest files, worst quality). A compression level of -1 uses the default compression level selected when zlib was compiled on your system, and is the same as calling png() with no argument.

See it explained GD docs.

I used png compression in my picwoodpecker -- a Tk program to choose and modify your photos (<- upvote here ;) that now is on github (<- newer version here ;)

Iirc the compression worked but in the windows machine where I'm now seems to not to have effect on the size/quality of the output (missing zlib?).

Try my (wonderful!) program above perl picwoodpecker.pl -pngcompression 0 go to advanced and set the output to png then use copy this photo from the main ineterface. Retry with -pngcompression 9

HtH

L*

There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

In reply to Re: Setting png compression level in Imager -- GD by Discipulus
in thread Setting png compression level in Imager by Anonymous Monk

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.