Not sure if the UNIX perms of 600 for the image may be causing a problem there.
The relevant entries from dokuwiki.php are:
$conf['umask'] = 0111; //set the umask for new files
$conf['dmask'] = 0000; //directory mask accordingly
Also, the same sympton is experienced if it's a GIF image as well. I actually converted the GIF to a PNG and uploaded it thinking that maybe GDLib was compiled without GIF support but looking at the phpinfo(); page, that does not appear to be the case.
Can you try setting $conf['gdlib'] to 0? Also can you attach the PNG file you used to this task?
Do you have acces to apache's error logs? Do you get any errors when calling the affected page?
Okay, with gdlib set to zero it loaded the image (albet a 1.3MB very small image). I was hoping to have DokuWiki create and cache a reduced version.
Setting gdlib to 1 produced the same effect (broken page).
Now setting gdlib back to 2 and will paste any error messages (if any).
Okay... absolutely no error messages in Apache's error_log file.
Attaching the PNG.
Well the image does work fine with my current devel version, but I changed some things how images are handled. The image is very big in size, did you have the same problems with smaller images? I assume it's some problem with libGD, but I really have no idea.
I think you're right that it is a libGD problem. I have not had problems with other PNG images. Also, as I said, GIFs have the same effect too (same size).
Any possibilities of work arounds? I really need those images to be that size considering some of the writing that's on them (in order to read them).
Well in case it's a libGD problem you could recompile PHP with another GD version, if that's an option for you. Or you could hack DokuWiki's sources to use an external tool (like ImageMagick) instead of libGD to do the resizing.