On Sun, 8 Feb 2009 16:02:59 -0500 [email protected] wrote:
| On Fri, 6 Feb 2009 23:36:52 -0800 | Dodger <[email protected]> wrote: | | >Would there be any way to do this in the PerlMagick API, though? | | I don't know if this will help, maybe you can do some | averaging on the values to get the same results as | Fred Weinhaus's shell method. | | #!/usr/bin/perl | use warnings; | use strict; | use Image::Magick; | | my $file = shift or die "Need a file $!\n"; | | my $img = Image::Magick->new; | $img->ReadImage($file); | | my $tot = 0; | my (@colors) = $img->Histogram(); | | #print join "\n\n", @colors; | | while (1){ | if (scalar @colors == 0){last} | my $r = shift @colors; | my $g = shift @colors; | my $b = shift @colors; | my $o = shift @colors; | my $count = shift @colors; | $tot++; | | my $rh = sprintf('%02X',$r); | my $gh = sprintf('%02X',$g); | my $bh = sprintf('%02X',$b); | | print "$count ($rh,$gh,$bh) at $o opacity\n"; | } | | print "\n$tot total colors\n"; | If all you want is to know if the image has transparency, do the above and 'short-circuit' the loop as soon as you see a transparent pixel. Of course if the input image is JPEG, then it will not have an alpha channel, so you probably should check as follows. if no alpha NOT TRANSPARENT if alpha... loop over all pixels if any non-opaque, abort loop with 'TRANSPARNT' if loop reached end NOT TRANSPARENT That will be FAST for JPEG, Generally FAST for images with transparency, and only slow for images that have alpha but all pixels are fully-opaque. That TEST however I believe is in the magick Core somewhere (Cristy will know) and may be able to be exported for API usage. A similar test that is also in MagicCore (somewhere) is a test for if the image is 'Gray Scale' of not. Anthony Thyssen ( System Programmer ) <[email protected]> ----------------------------------------------------------------------------- /Earth is 98% full. Please delete anyone you can! - rec.humor.funny ----------------------------------------------------------------------------- Anthony's Home is his Castle http://www.cit.gu.edu.au/~anthony/ _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
