Crop Bug Found!

[MGSteve]

No, its not a discussion about a pest for wheat, but very odd behaviour with MagickCropImage.

I've got a JPG which is loaded into a MW handle and is 800x575. It needs to be 800x574, so I use this command to criop the line off...

MagickCropImage($mwimage,800,574,0,1);

And for some reason the output is 800x563.

I've done a bit of digging around and I believe its definitely a bug. If you open the file, call the crop function then it works fine. However, this particular file has a lot of operations done on it before it calls the crop function.

I've just spent 30 mins tracking every MW call made and you can easily recreate this bug by doing the following..

downloading this file:
http://www.ukwebsystems.com/inc/0002/im ... master.jpg

& running this code...

Code: Select all

<?php
      
  $Master = 'master.jpg';
  $Production = 'production.jpg'; // Will be created
  $Proof = 'proof.jpg'; // Will be created

  $hFile = NewMagickWand();
  MagickReadImage($hFile,$Master);

  MagickResizeImage($hFile,3355,2514,MW_QuadraticFilter,1.0);
  MagickCropImage($hFile,3355,2410,0,52);
  MagickSetCompressionQuality($hFile,95);
  MagickWriteImage($hFile,$Production);
  MagickResizeImage($hFile,800,575,MW_QuadraticFilter,1.0);

  // Image height is 575
  MagickCropImage($hFile,800,574,0,1);
  // Image height is 563!

  $ImgH = MagickGetImageHeight($hFile); // $ImgH is now 563

  MagickWriteImage($hFile,$Proof);

?>

Interestingly if you remove the earlier call to MagickCropImage the image is then cropped correctly to 574.

Is there somewhere I should repost this to attract a developer's attention!

In the mean time as a work around, if you save the file before the last crop and then reopen it again and then crop it, its fine.

It just appears to be if you crop the same image twice it doesn't work.

[el_supremo]

Try adding
MagickResetImagePage($hfile,"0x0+0+0");
after the first crop. This will remove any virtual page info which may be interfering with the second crop.

Pete

[MGSteve]

Try adding
MagickResetImagePage($hfile,"0x0+0+0");
after the first crop. This will remove any virtual page info which may be interfering with the second crop.

Pete

Yup that fixed it.

Surely MagickCropImage should do this automatically?