Resize Bug in GIF about converjon

[selfawaresoup]

I can't reproduce this behaviour but I'm running slightly different versions of ImageMagick and Exiftool:

• ImageMagick 6.8.8-9
• Exiftool 9.54

My first guess would be a bug in ImageMagick that is fixed in this newer version.

[trendfischer]

Do we have an example ImageMagick-Command or can I log converjon commands, so that I can verify, ImageMagick is the problem?

[selfawaresoup]

The commands that converjon uses are logged when the "debug" option is set to truein the configs.

Here's the logged command for this GIF:

convert ./cache/source/localhost:8001/test.gif -crop 74x99+47+0 -resize 125x166! gif:./cache/target/localhost:8001/test.gif/905ebb9f63bf818765f4391885b0a68574977a49c9edbebea3627ad1e9893717.gif

I also did reproduce this problem with the later version of imagemagick. I was accidentally converting to JPEG before where the problem does not occur. It does only occur when converting to GIF, regardless of the source format.

[selfawaresoup]

$ identify test.gif
test.gif GIF 169x99 169x99+0+0 8-bit sRGB 64c 1.9KB 0.000u 0:00.000
$ convert test.gif -crop 74x99+47+0 -resize 125x166! gif:out.gif
$ identify out.gif
out.gif GIF 125x166 285x166+79+0 8-bit sRGB 256c 4.97KB 0.000u 0:00.000

There seems so be additional metadata in the output GIF that contains different dimensions for the image.

[neffets]

Same error on Suse SLES-11 SP3

error occurs while crop without resize:

$ identify test.gif
test.gif GIF 169x99 169x99+0+0 8-bit PseudoClass 64c 1.85kb
$ convert test.gif -crop 74x99+47+0 gif:crop.gif
$ identify crop.gif
crop.gif GIF 74x99 169x99+47+0 8-bit PseudoClass 64c 1.16kb
$ file crop.gif
crop.gif: GIF image data, version 89a, 169 x 99

[neffets]

There is an additional option for ImageMagick: "+repage" http://www.imagemagick.org/script/command-line-options.php#repage

That solves the GIF-problem:

$ identify test.gif
test.gif GIF 169x99 169x99+0+0 8-bit sRGB 64c 1.9KB 0.000u 0:00.000
$ convert test.gif -crop 74x99+47+0 +repage gif:crop.gif
$ identify crop.gif
crop.gif GIF 74x99 74x99+0+0 8-bit sRGB 64c 1.19KB 0.000u 0:00.000
$ file crop.gif
crop.gif: GIF image data, version 89a, 74 x 99

and

$ convert test.gif -crop 74x99+47+0 +repage -resize 125x166! gif:out.gif
$ identify out.gif
out.gif GIF 125x166 125x166+0+0 8-bit sRGB 256c 5.05KB 0.000u 0:00.000
$ file out.gif
out.gif: GIF image data, version 89a, 125 x 166

Please add this additional option to converjon for gif-conversion.

[selfawaresoup]

--- a/lib/converter.js
+++ b/lib/converter.js
@@ -104,6 +104,10 @@ var getConvertArgs = function(sourceFile, targetFile, options) {
                 args.push("-border", cropping.paddingX+"x"+cropping.paddingY);
         }

+    if (to == "gif") {
+        args.push("+repage");
+    }
+
         if (options.width && options.height) {
                 args.push("-resize", options.width+"x"+options.height+"!");
         } else if (options.width) {

This is a fix for 1.8.1, it should be included into 2.0.0.