ImageMagick - Revision history

Psmay at 03:13, 3 January 2015

2015-01-03T03:13:08Z

Psmay: /* Change a grayscale image to an alpha mask image (white as opaque) */

2015-01-03T01:22:06Z

Change a grayscale image to an alpha mask image (white as opaque)

Psmay: /* Snippets */

2015-01-03T00:50:10Z

Snippets

Psmay: /* Fill the background of an existing (partly transparent) image with a color */

2015-01-03T00:11:53Z

Fill the background of an existing (partly transparent) image with a color

Psmay at 20:00, 2 January 2015

2015-01-02T20:00:23Z

Psmay at 15:50, 2 January 2015

2015-01-02T15:50:41Z

Psmay: Created page with "'''ImageMagick''' is a common image processing program (`convert`) and library (e.g. PerlMagick, aka `Image::Magick`). ==PerlMagick snippets== ===Use m..."

2015-01-02T15:22:35Z

Created page with "'''ImageMagick''' is a common image processing program (<code>convert</code>) and library (e.g. PerlMagick, aka <code>Image::Magick</code>). ==PerlMagick snippets== ===Use m..."

New page

'''ImageMagick''' is a common image processing program (<code>convert</code>) and library (e.g. PerlMagick, aka <code>Image::Magick</code>).

==PerlMagick snippets==

===Use module===

<syntaxhighlight lang=perl>
use Image::Magick;
</syntaxhighlight>

@@ Line 114: / Line 114: @@
 my $alpha_mask = $gray_mask->Clone;
 $alpha_mask->Set(alpha => 'shape');
 </syntaxhighlight>

@@ Line 111: / Line 111: @@
 </syntaxhighlight>
-<code>-alpha shape</code> appears to have been added in a fairly recent version; for older versions this should work:
+<syntaxhighlight lang=perl>
+my $alpha_mask = $gray_mask->Clone;
-<syntaxhighlight lang=bash>
+$alpha_mask->Set(alpha => 'shape');
 </syntaxhighlight>

@@ Line 29: / Line 29: @@
 The default operation: Src (the foreground) is copied over dst (the background).
 <syntaxhighlight lang=bash>
 # The method may be omitted here
 composite -compose fg.png bg.png fg_on_bg.png
 # More verbosely
 composite -compose over fg.png bg.png fg_on_bg.png
 </syntaxhighlight>
@@ Line 43: / Line 46: @@
 # More verbosely
 $bg->Composite(method => 'over', image => $fg);
 </syntaxhighlight>
-====dst_over: Copy src behind dst====
+====in: Src with alpha mask of dst applied====
-The same as <code>over</code> but with roles reversed: src (now the background) is copied under dst (now the foreground). In Perl, this is a useful way to mutate the foreground instead of the background.
+<code>dst_in</code> is the same, but swaps src and dst.
 <syntaxhighlight lang=bash>
-composite -compose dst_over bg.png fg.png fg_on_bg.png
+composite -compose in image.png alpha-mask.png masked-image.png
 </syntaxhighlight>
 <syntaxhighlight lang=perl>
-# Result is $fg
+# Result is whichever object whose method is called
-$fg->Composite(compose => 'dst_over', image => $bg);
+$alpha_mask->Composite(method => 'in', image => $image);
 </syntaxhighlight>
@@ Line 101: / Line 111: @@
 </syntaxhighlight>
-===Apply an alpha mask image to another image===
+<code>-alpha shape</code> appears to have been added in a fairly recent version; for older versions this should work:
 <syntaxhighlight lang=bash>
-composite -compose in src.png alpha-mask.png result.png
+convert gray-mask.png '(' +clone ')' \
 </syntaxhighlight>

@@ Line 93: / Line 93: @@
 # Or mutate the existing foreground image (result $fg)
 $fg->Composite(compose => 'dst_over', image => $bg);
 </syntaxhighlight>

@@ Line 4: / Line 4: @@
 ===Composite===
 <syntaxhighlight lang=bash>
@@ Line 10: / Line 54: @@
 <syntaxhighlight lang=perl>
-my $fg_on_bg = $fg->Clone; # or just $fg, if destructive
+# Result is $fg
-$fg_on_bg->Composite(compose => 'dst_over', image => $bg);
+$fg->Composite(compose => 'dst_over', image => $bg);
 </syntaxhighlight>
@@ Line 29: / Line 73: @@
 my $filled = new Image::Magick size => "${width}x${height}";
 $filled->Read("xc:$color");
 </syntaxhighlight>

@@ Line 1: / Line 1: @@
 '''ImageMagick''' is a common image processing program (<code>convert</code>) and library (e.g. PerlMagick, aka <code>Image::Magick</code>).
-==PerlMagick snippets==
+==Snippets==
-===Use module===
+===Composite===
 <syntaxhighlight lang=perl>
-use Image::Magick;
+my $color = 'white';
 </syntaxhighlight>