Re: image offset

On Thu, 11 Jul 2019, mick crane wrote:
>
> the images are all over the place.
>
> I think what I want is -repage to get rid of the offset.
> I'm uncertain what the offset is supposed to do because same image with or 
> without seems to make no difference in the viewer.
> I'm not that good at Perl and need advice how to translate the gm 
> instructions into Perl syntax.
> where would I put "-repage" ?
> I also don't know how the actual .png files are constructed and wouldn't mind 
> a link to some resource that might help me understand how all these image 
> files work.

It is interesting that PNG stores these offsets and that the offsets 
are sometimes used when the file is later used.

I am not completely certain, but it may be that if you first set the 
image 'gravity' attribute to 'Forget' or 'NorthWest' and then set the 
'page' attribute to a geometry like "+0+0" you will achive success. 
This is based on reading the GetImageGeometry() code in magick/image.c 
and the SetAttribute() code in PerlMagick/Magick.xs pertaining to the 
"page" attribute.

Bob
-- 
Bob Friesenhahn
[email protected], http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
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