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Photoshop rasterising problem

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#1
Hans van der Maarel

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I'm having a problem with Photoshop:

I'm opening a GeoPDF and rasterize it at 300 dpi. It's a big file (about 30000 x 30000 pixels off the top of my head), but not the biggest I've ever seen/handled. It contains some vector data on top of a raster basemap.

After rasterizing it seems the vector layers are skewed. On the left side of the file, they align nicely with the raster basemap, on the left side they're a few pixels off. If I check the original PDF file in Illustrator or Acrobat, it all lines up, so somewhere in the rasterizing process there's an offset being introduced.

This happens on both Windows and Mac, with Photoshop CS6. I have Geographic Imager on my Mac, not on my Windows machine and this doesn't seem to be making any difference. Even saving the GeoPDF as a regular PDF and then rasterizing produces the same results.

Does anybody have any idea as to what may be causing this?
Hans van der Maarel - Cartotalk Editor
Red Geographics
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#2
Matthew Hampton

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I haven't come across this before, but I would think it has something to do with the "Geo" part of the file and how it was created. Does the same problem persist if you first re-save the PDF through Acrobat (thus eliminating the Geo-related code) then rasterize it in Photoshop?

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#3
Avenza

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This issue has been followed up on with the original poster as this was reported to Avenza's support department as well.

At this time after some initial testing we have yet not been unable to reproduce the same issue and have subsequently asked the poster to try a couple different scenario's including saving out as a standard Adobe pdf and opening it in Photoshop as well as opening the exported Geospatial pdf with Geographic Imager removed to see if there is any difference in the resulting file.

It is in the development departments opinion that this issue is likely not an issue with Geographic Imager however we have requested the file and are awaiting it for further testing.

Avenza Support

#4
Hans van der Maarel

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Looks like the issue is only present in CS6 (regardless of whether Geographic Imager is installed), when I ran it through CS5 the shift didn't occur. Still curious as to why this is happening, it's the first time I've ever seen it.
Hans van der Maarel - Cartotalk Editor
Red Geographics
Email: hans@redgeographics.com / Twitter: @redgeographics

#5
Jacques Gélinas

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Hans,

Just a suggestion,
but have you tried creating an EPS file from Illy and then rasterizing in PS (note that I would suggest not setting the antialias option when rasterizing).

regards,

Jacques Gélinas
cartographer
www.cartesgeo.ca





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