Making imagemaps from images

The contact.perl script was used to read a list of files from stdin (most likely as the output of ls) and make a series of interlaced/transparent GIFs and imagemap files.

What's new

1995/03/14

• The final GIF creating phase would occasionally fail. (Fix courtesy rck@sgi.com.)

1995/03/07

• You can now get just one imagemap and GIF file by setting the makeitfit variable

first release

• You can modify contact.perl variables by having appropriate perl commands in the file .contact.perlrc in the current (searched first) or HOME directory.
• BW and WW can now be zero.
• TP sets the border width for the image preview text strings (it too can be zero).
• BDFFILE gives the full pathname for a BDF font to be used for the image preview text.
• It will now deal better with ls -C output.
• netpbm programs are used rather than pbmplus programs.

How to use it

To make a series of image maps of the beer images avalable in our environment I did something like this:

	mkdir /tmp/work
	cd /tmp/work
	setenv TMPDIR .
	ls /ftp/pub/beermats/*.{gif,jpg} | contact.perl

The contact.perl script then makes as many all*.gif and all*.map files as it needs to contain small copies of the images; and makes an index.html, text.html, and map.html file with the hypertext references.

You'll then need to copy the files into one of your public_html directories and update your imagemap configuration file. This is what I'd do (following from above):

	set ddir=~/public_html/beermats
	chmod 644 *
	cp -p * $ddir
	cd $ddir
	foreach i (all*.map)
		echo $i
		echo `basename $i .map` : $ddir/$i >> imagemap.conf
	end

contact.perl bugs

• The makeitfit algorythm is very basic. It assumes that the images in the imagemap are roughly square.
• It's a mess!
• It makes a whole lot of temporary files in /tmp or TMPDIR.
• I had shift, unshift, and push on my brain.
• Too many things are hardwired
• It leaves lots of litter around if it's interrupted
• It doesn't deal with filenames that contain whitespace. It may think you did ls -C.
• If you don't tell it to be quiet it will be quite noisy.

missing features

• Perhaps those variables should be command line switches
• A way should be provided to allow custom text in the generated .html files.

contact.perl internals

The following variables may be useful in the .contact.perlrc file:

WIDTH

maximum width of contact sheet

HEIGHT

maximum height

PICW

maximum width of preview images

PICH

maximum height

WW

White Width of border around preview images

BW

Black Width of border (will become transparent)

TP

The width of the border around the image text (Text Padding)

BDFFILE

The full path of a BDF file to use for the image text font. eg: /usr/local/X11R6/xc/fonts/bdf/75dpi/helvBO12.bdf

SERVER

Where the real images will be found. eg: http://www.csi.uottawa.ca

LOCPREFIX

The directory relative to SERVER where the images are kept. eg: $SERVER/ftppub/beermats

CGIIMAGEMAP

The path relative to SERVER that will run the imagemap eg: cgi-bin/imagemap/~user/dirpath

quiet

set this to 0 to see the action

addtext2pic

set this to 0 if you don't want the filename in the preview images

makeitfit

set this to 1 if you want contact.perl to find the best values for PICW and PICH for the values of WIDTH and HEIGHT.

Sample .contact.perlrc file

	$makeitfit = 1;
	$BW = 0;
	$WW = 0;
	$addtext2pic = 0;
	$WIDTH = 500;
	$HEIGHT = 450;
	$SERVER = "http://www.csi.uottawa.ca";
	$CGIIMAGEMAP = "cgi-bin/imagemap/~kwhite/beermats";
	$LOCPREFIX = "$SERVER/ftppub/beermats";

kwhite@csi.uottawa.ca 1995/03/15