xv and png

[Joerg van den Hoff]

On Fri, Apr 04, 2008 at 08:02:43PM -0500, Ryan Schmidt wrote:
> On Apr 4, 2008, at 19:39, Rainer Müller wrote:
> 
> >Joerg van den Hoff wrote:
> >
> >>standard  `xv'   does  not have png support although patches
> >>seem to exist.
> >
> >The standard xv release does not support PNG images according to  
> >the homepage. Even if there are any patches available somewhere,  
> >they are not applied at the moment.
> >
> >There is an official patch on the downloads page, "Patch to read/ 
> >write PNG files" [1].
> >
> >The statement in the description is, "This version has been patched  
> >to support the PNG & PhotoCD image types." But it seems that it is  
> >just using the standard source distribution without additional  
> >patches.
> >
> >>`port  info  xv'  lists `libpng'  as one of the dependencies
> >>and PNG is explicitely mentioned under  the  supported  file
> >>formats.   therefore  I installed it hoping for PNG support,
> >>but without success: no display of png images.
> >
> >Strange enough, it is really linked against libpng. But it can't  
> >display PNG images for me neither.
> >
> >$ otool -L /opt/local/bin/xv
> >/opt/local/bin/xv:
> >[...]
> >        /opt/local/lib/libjpeg.62.dylib (compatibility version  
> >63.0.0, current version 63.0.0)
> >        /opt/local/lib/libtiff.3.dylib (compatibility version  
> >12.0.0, current version 12.2.0)
> >        /usr/X11/lib/libpng.3.dylib (compatibility version 4.0.0,  
> >current version 4.0.0)
> >[...]
> 
> Looks like it's also linked against the system's libpng, not  
> MacPorts' libpng, which is unfortunate and should be fixed.
> 

is mr. nomaintainer informed? :-)

and it would be really great, if the PNG patch could really be 
included: missing PNG support is the one big shortcoming of `xv'.
as `xv' seems otherwise frozen since the mid nineties applying the patch
seems a one time action.

and for standard tasks `xv' still seems really superior to
`ImageMagick' (standard operations such as edge detection run faster
by a signifcant factor (5-10) and yield really much better results).

joerg