It seems that w3m is not able to display images in terminals wich have a color depth of 32 bits (like urxvt).
Steps to reproduce:
Run w3m in a terminal wich support a color depth of 32 bits:
- for urxvt add the string URxvt.depth:32 to the file Xresources, and reload it using xrdb
- start a new instance of urxvt
- run w3m in the new instance of urxvt Try to display some images (for example search something in google images)
There is also a discussion on the github page of ranger, in wich the issue is described:
https://github.com/hut/ranger/issues/86
And here there is also a patch that seems to solve the issue:
https://gist.github.com/BwackNinja/60a344730170f9ce2163
Merged in Debian. Thanks.
Additional patch for gdk-pixbuf is available, merged in Debian.
Also, problems with resized images for Imlib2 has been fixed,
merged in Debian.
cf. https://github.com/hut/ranger/issues/86#issuecomment-166027119