EPS - Aliasing, Moire Problem

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al3x

EPS - Aliasing, Moire Problem

Post by al3x »

Hi

This is my very first post here,
I'm using IM with Lasso Integrated Wrapper (http://www.lassosoft.com/), I'm trying to convert EPS files to JPG so I installed Ghostmagick and It's works like a charm.

But I have a kind of aliasing or Moire effect on my JPG, like this :

Image

The EPS are at 305 dpi so I tried :

Code: Select all

mogrify -density 305 -format jpg
But it's still the same, I also tried -resample (72 and 305), -colorspace (RGB) and lot of differents parameters with no success. So I need your Help ! :)

This is the link for EPS source file and the link for result JPG file

Thank you for your help ! Greetings from france
Bonzo
Posts: 2971
Joined: 2006-05-20T08:08:19-07:00
Location: Cambridge, England

Re: EPS - Aliasing, Moire Problem

Post by Bonzo »

I wonder if that is a jpg compression problem ? I would try saving as a png and see what happens; you can also add a -quality to the comand try -quality 100 for the least compression.
http://www.imagemagick.org/script/comma ... hp#quality
al3x

Re: EPS - Aliasing, Moire Problem

Post by al3x »

Thank you for your answer, I tried PNG with -quality 100 and it's still the same.

I re-opened the EPS in photoshop and re-saved it with "72 DPI no resampling"
JPG conversion in IM are perfect now but the problem is that I can't modify the EPS, I need to deal it with its native 305 DPI density...
al3x

[SOLVED] Re: EPS - Aliasing, Moire Problem

Post by al3x »

I compiled Ghostscript 8.63 and run this command :

Code: Select all

gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=jpeg -dAlignToPixels=0  -sOutputFile=test.jpg -r305 -dGridFitTT=0 -dEPSCrop src.eps
And it did the trick
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magick
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Re: EPS - Aliasing, Moire Problem

Post by magick »

We have a patch for the problem you reported. It will be available sometime tomorrow in the Subversion trunk and in the next point release within a few days. Thanks.
al3x

Re: EPS - Aliasing, Moire Problem

Post by al3x »

magick wrote:We have a patch for the problem you reported. It will be available sometime tomorrow in the Subversion trunk and in the next point release within a few days. Thanks.
Cool thanks ! Could you let me know what was the problem ?
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magick
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Re: EPS - Aliasing, Moire Problem

Post by magick »

The problem was that the resolution was set before we read the XMP profile which updated the resolution. In your case it went from 72 to 305.
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