105
edits
User talk:BytePilot: Difference between revisions
From London Hackspace Wiki
working!
No edit summary |
(working!) |
||
| Line 236: | Line 236: | ||
} | } | ||
</pre> | </pre> | ||
<hr> | |||
OK, well its good to see that it's working more-or-less. | |||
I've been trying to get it to accept a value instead of a percentage - it will - have to assume that MaxRGB = 256 (which depends on the settings when GraphicsMagick was compiled - so in a way it would be more portable to do it as a percentage - but values less than 1% appear to be rounded by GM). | |||
so anyway, if we assume MaxRGB = 256 then it works OK. | |||
http://hack.rs/cgi-bin/threshold_grayscale.pl | |||
<pre> | |||
#!/usr/bin/perl -w | |||
use strict; | |||
use CGI; | |||
use CGI::Carp qw(fatalsToBrowser warningsToBrowser); | |||
use List::Util qw(max min); | |||
my $q = CGI->new(); | |||
print $q->header; | |||
print $q->start_html; | |||
print $q->p("this is a thing for doing threshholding"); | |||
print $q->p("<small>or possibly <i>thresholding</i>?</small>"); | |||
print $q->start_form( -enctype => "multipart/form-data" ); | |||
print $q->p("file"); | |||
print $q->filefield('uploaded_file'); | |||
print $q->submit(); | |||
print $q->end_form; | |||
# do we have an upload? | |||
my $filehandle = $q->upload('uploaded_file'); | |||
if (defined $filehandle) { | |||
# do shit | |||
print $q->p("I'm doing shit"); | |||
# no, actually do shit | |||
my ($filename, $extension) = ($q->param('uploaded_file') =~ /^(\S+)\.(\S+)$/); | |||
my $tempfile = $q->tmpFileName($q->param('uploaded_file')); | |||
foreach my $i (0 .. 7) { | |||
my $n = 2 ** $i; | |||
my $outfile = "$filename"."_$i.$extension"; | |||
my @ar = ("gm", | |||
"convert", | |||
"-operator", "Gray", "And", $n , | |||
"-operator", "Gray", "Threshold", $n - 1 , | |||
$tempfile, | |||
"/var/www/threshold_output/$outfile" ); | |||
print $q->p("$i : " . join " ", @ar); | |||
system(@ar) == 0 or die "system call failed: $? $!"; #safer than passing a string to system(), | |||
# because doing it this way bypasses the shell | |||
print $q->img({src => "/threshold_output/$outfile"}); | |||
} | |||
} | |||
print $q->end_html; | |||
</pre> | |||
--[[User:AndyE|AndyE]] 12:21, 13 January 2011 (UTC) | |||
<hr> | |||
