ref: 517b14e666b0b71fc0bcd5da1b22cdc90d3434c9
dir: /icons/square.pl/
#!/usr/bin/perl # Read an input image, crop its border to a standard width, and # convert it into a square output image. Parameters are: # # - the required total image size # - the output border thickness # - the input image file name # - the output image file name. ($convert, $osize, $oborder, $infile, $outfile) = @ARGV; # Determine the input image's size. $ident = `identify -format "%w %h" $infile`; $ident =~ /(\d+) (\d+)/ or die "unable to get size for $infile\n"; ($w, $h) = ($1, $2); # Read the input image data. $data = []; open IDATA, "-|", $convert, "-depth", "8", $infile, "rgb:-"; push @$data, $rgb while (read IDATA,$rgb,3,0) == 3; close IDATA; # Check we have the right amount of data. $xl = $w * $h; $al = scalar @$data; die "wrong amount of image data ($al, expected $xl) from $infile\n" unless $al == $xl; # Find the background colour, by looking around the entire border # and finding the most popular pixel colour. for ($i = 0; $i < $w; $i++) { $pcount{$data->[$i]}++; # top row $pcount{$data->[($h-1)*$w+$i]}++; # bottom row } for ($i = 1; $i < $h-1; $i++) { $pcount{$data->[$i*$w]}++; # left column $pcount{$data->[$i*$w+$w-1]}++; # right column } @plist = sort { $pcount{$b} <=> $pcount{$a} } keys %pcount; $back = $plist[0]; # Crop rows and columns off the image to find the central rectangle # of non-background stuff. $ystart = 0; $ystart++ while $ystart < $h - 1 and scalar(grep { $_ ne $back } map { $data->[$ystart*$w+$_] } 0 .. ($w-1)) == 0; $yend = $h-1; $yend-- while $yend > $ystart and scalar(grep { $_ ne $back } map { $data->[$yend*$w+$_] } 0 .. ($w-1)) == 0; $xstart = 0; $xstart++ while $xstart < $w - 1 and scalar(grep { $_ ne $back } map { $data->[$_*$w+$xstart] } 0 .. ($h-1)) == 0; $xend = $w-1; $xend-- while $xend > $xstart and scalar(grep { $_ ne $back } map { $data->[$_*$w+$xend] } 0 .. ($h-1)) == 0; # Decide how much border we're going to put back on to make the # image perfectly square. $hexpand = ($yend-$ystart) - ($xend-$xstart); if ($hexpand > 0) { $left = int($hexpand / 2); $xstart -= $left; $xend += $hexpand - $left; } elsif ($hexpand < 0) { $vexpand = -$hexpand; $top = int($vexpand / 2); $ystart -= $top; $yend += $vexpand - $top; } $ow = $xend - $xstart + 1; $oh = $yend - $ystart + 1; die "internal computation problem" if $ow != $oh; # should be square # And decide how much _more_ border goes on to add the bit around # the edge. $realow = int($ow * ($osize / ($osize - 2*$oborder))); $extra = $realow - $ow; $left = int($extra / 2); $xstart -= $left; $xend += $extra - $left; $top = int($extra / 2); $ystart -= $top; $yend += $extra - $top; $ow = $xend - $xstart + 1; $oh = $yend - $ystart + 1; die "internal computation problem" if $ow != $oh; # should be square # Now write out the resulting image, and resize it appropriately. open IDATA, "|-", $convert, "-size", "${ow}x${oh}", "-depth", "8", "-resize", "${osize}x${osize}!", "rgb:-", $outfile; for ($y = $ystart; $y <= $yend; $y++) { for ($x = $xstart; $x <= $xend; $x++) { if ($x >= 0 && $x < $w && $y >= 0 && $y < $h) { print IDATA $data->[$y*$w+$x]; } else { print IDATA $back; } } } close IDATA;