54 lines
1.5 KiB
Perl
Executable File
54 lines
1.5 KiB
Perl
Executable File
#!/usr/bin/perl
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#
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# Example of modifying all the pixels in an image (like -fx).
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#
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# Currently this is slow as each pixel is being lokedup one pixel at a time.
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# The better technique of extracting and modifing a whole row of pixels at
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# a time has not been figured out, though perl functions have been provided
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# for this.
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#
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# Also access and controls for Area Re-sampling (EWA), beyond single pixel
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# lookup (interpolated unscaled lookup), is also not available at this time.
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#
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# Anthony Thyssen 5 October 2007
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#
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use strict;
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use Image::Magick;
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# read original image
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my $orig = Image::Magick->new();
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my $w = $orig->Read('rose:');
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warn("$w") if $w;
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exit if $w =~ /^Exception/;
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# make a clone of the image (preserve input, modify output)
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my $dest = $orig->Clone();
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# You could enlarge destination image here if you like.
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# And it is posible to modify the existing image directly
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# rather than modifying a clone as FX does.
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# Iterate over destination image...
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my ($width, $height) = $dest->Get('width', 'height');
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for( my $j = 0; $j < $height; $j++ ) {
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for( my $i = 0; $i < $width; $i++ ) {
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# read original image color
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my @pixel = $orig->GetPixel( x=>$i, y=>$j );
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# modify the pixel values (as normalized floats)
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$pixel[0] = $pixel[0]/2; # darken red
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# write pixel to destination
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# (quantization and clipping happens here)
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$dest->SetPixel(x=>$i,y=>$j,color=>\@pixel);
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}
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}
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# display the result (or you could save it)
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$dest->Write('win:');
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$dest->Write('pixel-fx.gif');
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