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powershellimagemagickcrop

ImageMagick crop with row/column in file name only saving last image

I'm attempting to crop an image using ImageMagick and via PowerShell. I can crop the image fine with the following command, and it creates the 2000+ images:

convert -crop 16x16 .\original.png tileOut%d.png

However, I would like to take advantage of ImageMagick's ability to dynamically set the file name.

According to a post on their forums I should be able to run something like the following via a batch file:

convert ^
   bigimage.jpg ^
  -crop 256x256 ^
  -set filename:tile "%%[fx:page.x/256+1]_%%[fx:page.y/256+1]" ^
  +repage +adjoin ^
  tiled_%%[filename:tile].gif

I shouldn't need to escape the % since I'm running this in PowerShell directly, so I used the following:

convert -crop 16x16 .\original.png -set filename:tile "%[fx:page.x/16+1]_%[fx:page.y/16+1]" +repage +adjoin directory\tiled_%[filename:tile].png

However, when I run this command I end up with one file called tiled_%[filename and another called tiled_45_47.png.

So while it does seem to create the last file, it only creates the one. The first file is 0 bytes in size, but takes up over 8 MB of space on disc, according to properties on the file.

Trying to run the command in a batch file results in the same behavior, which makes me think PowerShell itself isn't the issue, but rather the command is.

According to the documentation +adjoin is required since I want different images. +repage doesn't make much sense to me, but I've kept it in the command since the original had it, and excluding it doesn't seem to change the output. -set filename seems pretty straightforward.

Large size of the first leads me to believe that all the previous images might be getting added to it. However, the file name also suggests it's getting hung up on the :, but it doesn't appear to be a special character in PowerShell. It's also creating an image for the very last crop. Baffling.

So what am I doing wrong?

Thanks in advance!

EDIT:

  • PowerShell 5.0.10586.0, on Windows 10.
  • ImageMagick 6.9.2 Q16 (64-bit)

From the comments, I'm thinking the issue might be with the ImageMagick command.

Solution

  • I'm not using Powershell, but I think you will have more success by specifying your image first, then the crop, then setting the filename:

    convert original.png -crop 16x16 -set filename:tile "%[fx:page.x/16+1]_%[fx:page.y/16+1]" +repage "tiled_%[filename:tile].png"