terminal transparency, Imagemagick, and X11 root window problem

Question

In Ubuntu Natty and in Fedora 12, I have urxvt (with 256 colours), and use ImageMagick (display -window root [...]) to set the root window to a picture. When I use the transparency (-tr) option on urxvt, I get the X11 login screen background (The pink/purple one in Ubunutu, the Blue one in Fedora) and not the image that is currently on the root window. See picture at the bottom -- taken from Ubuntu but similar to Fedora.

Note that the same problem exists if I run gnome-terminal and set its transparency.

I suspect that ImageMagick is not drawing on the right X11 layer but I (and google) cannot figure out what the right option is.

Could the problem be with either the xorg configuration or with window composition?

I would be happy to use something else than Imagemagick as long as I can re-size the images on the fly (so it keeps its current aspect ratio and fits within the visible screen area) and that I can centre the image on the bottom right corner of the screen.

Answer 1

I've had a similar problem with awesome window manager as well as urxvt, when ImageMagick was used to set the background. It got quickly resolved with feedback from the author of awesome - you can see the archive of this conversation on gmane archives - here and further on here.

The solution was to change the background setter and I chose to use habak because it was the lightest one. You can also use other, like feh or Esetroot (belongs to Enlightenment WM). I think I would recommend you to try feh first, since it seems to be packaged for many distros.

Side note: In case someone wanted to try out many different bg-setters, here's a list of those that awsetbg (bg-setting wrapper script from awesome) tries to use:

Esetroot habak feh hsetroot chbg fvwm-root imlibsetroot display qiv xv xsri xli xsetbg wmsetbg xsetroot

Note that some of those only come shipped with bigger packages.

Edit: Looking at xsri manpage, I think it might provide best flexibility for your needs.

Answer 2

I may be wrong, but did you try to set the image with xli?

xli -onroot myimage.png

The man page says

NAME
       xli - load images into an X11 window or onto the root window

SYNOPSIS
       xli [global_options] {[image_options] image ...}
       xli [global_options] [image_options] stdin < image

DESCRIPTION
       xli  displays  images  in  an  X11  window  or loads them onto the root
       window.  See the IMAGE TYPES section below for supported image types.

       If the filename stdin is given, xli will read the image  from  standard
       input.  

Answer 3

Well, since xsri is no longer maintained, this is now the solution to the problem: use convert to convert all images so that they are the right size and the right format, save them in another directory and use feh to display them. Very inelegant indeed but works.

#!/bin/sh
# Run this in your image directory
dir=$HOME/wallpapers
for file in *
do
    echo "Doing $file"
    convert -resize '1600x1200>' -extent 1600x1200 -background '#000000' \
        -gravity SouthEast  $file $dir/$file
done

Note that the resize option must be before the extend one.

Then use feh or whatever and centre the image on your display. Meh.

Answer 4

Convert the image using Imagemagick's convert and pipe the result to feh to diplay it as background, which also works for transparent terminals:

convert "$file" -resize 1600x1200 png:- | feh --bg-center -

Of course convert can do almost anything to your image. Much more than any background setter ever will.