transparency not coming through on pdf to jpg on pdf 1.4 thr

[afonit]

in illustrator you can save as
Acrobat 4 (PDF 1.3)
Acrobat 5 (PDF 1.4)
Acrobat 6 (PDF 1.5)
Acrobat 7 (PDF 1.6)
Acrobat 8 (PDF 1.7)

1.3 works with image magic fine, but 1.4-1.7 put a white background where the transparency is.

see post below reporting the issue.

viewtopic.php?f=1&t=13131

[magick]

Add -colorspace rgb to your command line:

• convert -colorspace rgb -verbose 1.5.pdf 1.5.png

[afonit]

the -colorspace rgb seems to be working fine.

that was not something that I had considered that I needed to convert to rgb from the cmyk in the ads/images.


Thank you for the tip, and I will continue to test it out with other images.

thanks again.

[afonit]

Add -colorspace rgb to your command line:

• convert -colorspace rgb -verbose 1.5.pdf 1.5.png

just tried again, and it does something wonky with the green(making it ultra bright):

http://www.mediafire.com/imageview.php? ... ym&thumb=5

though the fades/transparencies are coming through now.

[magick]

Post a URL to your PDF / Postscript source image so we can reproduce the problem.

[afonit]

here is the file:


http://www.mediafire.com/?sharekey=1140 ... eaa7bc68bc

[magick]

Can you check the link. No files were available for download.

[afonit]

went back, got this link


http://www.mediafire.com/?njdnqmoy3mz

[magick]

ImageMagick calls the Ghostscipt delegate to render PDF. When you use the -colorspace option before the PDF, it defaults to Ghostscript's internal CMYK to RGB algorithm. If you do not use the -colorspace option, you end up using the ImageMagick CMYK to RGB algorithm which differs from Ghostscript. To control the CMYK to RGB color conversion, use color profiles with the -profile option.

[afonit]

thank you for that explanation, I will research and play around with those options.

[afonit]

As an aside, is there a way to just keep the pdf that is in cmyk to convert to a jpg etc that is cmyk? so there is no color conversion between cmyk and rgb?

[magick]

If your original PDF is CMYK, you can produce a CMYK JPEG image with this command:

• convert cmyk.pdf cmyk.jpg

To verify

• identify -verbose cmyk.jpg

[afonit]

If your original PDF is CMYK, you can produce a CMYK JPEG image with this command:

• convert cmyk.pdf cmyk.jpg

To verify

• identify -verbose cmyk.jpg

yes, doing that just revealed to me what is happening. in the verbose of identify I see the background is set to white. so the transparency around the guy is showing through to the white background instead of it being transparent and showing the gray that is around him and behind him in the pdf document.

So the conversion is taking the transparency and knocking out what is behind it all the way through the document to the background. So that would be why it is not inheriting the surrounding color as something is telling the transparency to knockout all the way back to the background.