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Section: XScreenSaver manual (6)
Updated: 5.04 (13-Nov-2007)
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webcollage - decorate the screen with random images from the web  


webcollage [-display host:display.screen] [-root] [-window-id id] [-verbose] [-timeout secs] [-delay secs] [-background bg] [-no-output] [-urls-only] [-imagemap filename-base] [-size WxH] [-opacity ratio] [-filter command] [-filter2 command] [-http-proxy host[:port]] [-dictionary dictionary-file] [-driftnet [cmd]]  


The webcollage program pulls random image off of the World Wide Web and scatters them on the root window. One satisfied customer described it as "a nonstop pop culture brainbath." This program finds its images by doing random web searches, and extracting images from the returned pages.

webcollage is written in perl(1) and requires Perl 5.

It will be an order of magnitude faster if you also have the webcollage-helper program installed (a GDK/JPEG image compositor), but webcollage works without it as well.

webcollage can be used in conjunction with the driftnet(1) program (the Unix equivalent of EtherPEG) to snoop images from traffic on your local subnet, instead of getting images from search engines.  


webcollage accepts the following options:
Draw on the root window. This option is mandatory, if output is being produced: drawing to a window other than the root window is not yet supported.

Images are placed on the root window by using one of the xscreensaver-getimage(1), chbg(1), xv(1), xli(1), or xloadimage(1) programs (whichever is available.)

-window-id id
Draw to the indicated window instead; this only works if the xscreensaver-getimage(1) program is installed.
-verbose or -v
Print diagnostics to stderr. Multiple -v switches increase the amount of output. -v will print out the URLs of the images, and where they were placed; -vv will print out any warnings, and all URLs being loaded; -vvv will print information on what URLs were rejected; and so on.
-timeout seconds
How long to wait for a URL to complete before giving up on it and moving on to the next one. Default 30 seconds.
-delay seconds
How long to sleep between images. Default 2 seconds. (Remember that this program probably spends a lot of time waiting for the network.)
-background color-or-ppm
What to use for the background onto which images are pasted. This may be a color name, a hexadecimal RGB specification in the form '#rrggbb', or the name of a PPM file.
-size WxH
Normally, the output image will be made to be the size of the screen (or target window.) This lets you specify the desired size.
-opacity ratio
How transparently to paste the images together, with 0.0 meaning "completely transparent" and 1.0 meaning "opaque." Default 0.85. A value of around 0.3 will produce an interestingly blurry image after a while.
If this option is specified, then no composite output image will be generated. This is only useful when used in conjunction with -verbose.
If this option is specified, then no composite output image will be generated: instead, a list of image URLs will be printed on stdout.
-imagemap filename-base
If this option is specified, then instead of writing an image to the root window, two files will be created: "base.html" and "base.jpg". The JPEG will be the collage; the HTML file will include that image, and an image-map making the sub-images be linked to the pages on which they were found (just like
-filter command
Filter all source images through this command. The command must take a PPM file on stdin, and write a new PPM file to stdout. One good choice for a filter would be:

webcollage -root -filter 'vidwhacker -stdin -stdout'

-filter2 command
Filter the composite image through this command. The -filter option applies to the sub-images; the -filter2 applies to the final, full-screen image.
-http-proxy host:port
If you must go through a proxy to connect to the web, you can specify it with this option, or with the $http_proxy or $HTTP_PROXY environment variables.
-dictionary file
Webcollage normally looks at the system's default spell-check dictionary to generate words to feed into the search engines. You can specify an alternate dictionary with this option.

Note that by default, webcollage searches for images using several different methods, not all of which involve dictionary words, so using a "topical" dictionary file will not, in itself, be as effective as you might be hoping.

-driftnet [ args ]
driftnet(1) is a program that snoops your local ethernet for packets that look like they might be image files. It can be used in conjunction with webcollage to generate a collage of what other people on your network are looking at, instead of a search-engine collage. If you have driftnet installed on your $PATH, just use the -driftnet option. You can also specify the location of the program like this:

-driftnet /path/to/driftnet

or, you can provide extra arguments like this:

-driftnet '/path/to/driftnet -extra -args'

Driftnet version 0.1.5 or later is required. Note that the driftnet program requires root access, so you'll have to make driftnet be setuid-root for this to work. Please exercise caution.



to get the default host and display number.
to get the name of a resource file that overrides the global resources stored in the RESOURCE_MANAGER property.
http_proxy or HTTP_PROXY
to get the default HTTP proxy host and port.


/usr/dict/words, /usr/share/lib/dict/words, or /usr/share/dict/words to find the random words to feed to certain search engines.,,, and to find random web pages.  


The Internet being what it is, absolutely anything might show up in the collage including -- quite possibly -- pornography, or even nudity.  


Animating GIFs are not supported: only the first frame will be used.  


The latest version of webcollage can be found as a part of xscreensaver, at, or on the WebCollage page at



X(1), xscreensaver(1), xli(1), xv(1), xloadimage(1), ppmmake(1), giftopnm(1), pnmpaste(1), pnmscale(1), djpeg(1), cjpeg(1), xdpyinfo(1), perl(1), vidwhacker(6), dadadodo(1), driftnet(1) EtherPEG, EtherPeek  


Copyright © 1998-2005 by Jamie Zawinski. Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. No representations are made about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.  


Jamie Zawinski <>, 24-May-1998.