Re: [GM-help] how to crop an image and repage using magic_wand c api?

[Ben Wu <wu...@gm...>]

Thank you Bob!

I have attached a standalone command line program as well as the input
image and output image. To run it you just do

crop-gm  mar528_200_resized.gif mar528_crop75.gif 75 75 50 0 1

Ben

On Thu, Oct 25, 2012 at 11:08 PM, Bob Friesenhahn
<bfr...@si...> wrote:
> On Thu, 25 Oct 2012, Ben Wu wrote:
>
>> Thank you Bob. I tried the new functions but I am not getting the
>> right results or maybe I am not calling it correctly. The output image
>> is attached. My code snippet is below:
>
>
> I see that bad page offset in your GIF.
>
>
>>
>>        MagickWand *sc;
>>        MagickWand* dst;
>>        // ....more code ....
>>         dst = MagickCoalesceImages(src);
>>        MagickResetIterator(dst);
>>        while(MagickNextImage(dst) != MagickFalse)
>>        {
>>                  MagickCropImage(dst, 75, 75, 39, 0);
>>                 MagickSetImagePage(dst, 0, 0, 0, 0);
>>        }
>>
>>        MagickResetIterator(dst);
>>        out = MagickWriteImageBlob(dst, &image_blob_length);
>>        ....
>>
>>
>> I can crop jpeg fines. In fact to crop jpegs, i dont even need to call
>> the MagickResetImagePage function.
>
>
> That is because JPEG does not store page offsets.
>
> I am not seeing a problem in the code.
>
> Can you please send a tiny stand alone source file which recreates the
> problem so that we can be sure of using the same code and that a strange
> side-effect is not coming from other code?
>
>
> Bob
> --
> Bob Friesenhahn
> bfr...@si..., http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/