[gtk-list] Re: Displaying JPEGs

[john giorgio hart bbk ac uk]

>On 13 Feb, Mike Lindahl scribbled:
> >->  I am relatively new to GTK and am trying to get jpegs to display.  I am
> >->  using the libjpeg library and that is not a problem.  I have successfully
> >->  loaded the image into an array of memory.
> >->
> >->  My problem comes in trying to display it.  My first idea was to use
> >->  successive calls to gdk_draw_point.  This works, however, it takes _way_

grundman@cs.uni-duesseldorf.de (Sven Grundmann) wrote:
> I am stuck on a similar problem. That's why I joined this list ;)
> I want to display an 8-bit gray scale image stored in an array,
>
> ...
>
> Also, related to slow color allocation, how would you display many
> lines of various colors as fast as possible?

If you want something that will dither an RGB image from memory into an X
window, you need the gdk_rgb_*() functions. Take a look at testrgb in the gtk
sources.

Someone else wrote:
>>there is a whole library designed just to do all of this:
>>
>>http://www.labs.redhat.com/imlib/
>>
>>save yourself a lot of work :)

imlib is great if you want something that works at a higher level. Check out
the url above for an introduction.

John
--
John Cupitt, john.cupitt@ng-london.org.uk, +44 (0)171 930 2108
VASARI Lab, The National Gallery, Trafalgar Square, London, WC2N 5DN