Pitstop Pro 09 – converting RGB images

[RVNG]

Converting images from RGB to CMYK seems to be easy enough using Global change – “Convert to Color Space (Device CMYK)” and after doing so, I check the images and they have indeed converted to CMYK... so, all is well.

However, when I go convert the PDF to PDFx-1a using Acrobat 9’s preflight profiles the image converts back to RGB, and the preflight fails. The image in question has transparency but should that matter?

What is your procedure to convert RGB PDF files into PDFx-1a compliant files using Pitstop?.

 

[Sev]

I use the Image Touch-up tool in Acrobat, right-click on the image, select Edit Image. This will open up the image in PhotoShop. Convert the RGB to CMYK in PhotoShop and save. The image in the PDF will now be CMYK. Using PitStop, click on Certify PDF. Pick the PDF/X-1a profile that you wish to use, and let PitStop preflight and certify the PDF to be an error-free PDF/X-1a. I hope this what you are trying to achieve.

-Sev

 

[RVNG]

Thanks Sev,

I have used the Certified PDF Panel and have chosen the "PDFx-1a:2001 v5.0" preflight profile. After processing the panel reports 2 errors:

- ICC Based is used (96x on page1)
- Transparent objects have been found (2z on page 1)

I am guessing Pitstop cannot remove ICC profiles and flatten transparency to produce compliant PDFs, have you had similar errors in the past?

Thanks.
RG

 

[mattbeals]

PitStop can certainly remove the profiles and make a valid X-1a. Are you having PitStop convert all ICC based spaces to CMYK?

Do you want to convert tagged (calibrated) CMYK to CMYK?
Do you want to strip ICC profiles from CMYK objects?
Do you want to convert un/tagged RGB to CMYK?

All of these can be done with PitStop, but you have to configure color management in the preferences AND be sure of how you are instructing PitStop to convert colors in the preflight profile.

PitStop cannot flatten transparency. You are going to have to use Acrobat Pro to do this part of it. You can use Acrobat Pro to convert to a PDF/X-1a and as part of it's preflight process it will flatten transparency and handle the color conversions.

You can also use callas pdfToolbox which uses Acrobat's flattening engine and it will handle all of this for you.

But... PitStop is perfectly capable of making a valid X-1a.

 

[RVNG]

Thanks mattbeals,

I've been playing around with custom preflight profiles in Pitstop and have successfully remove ICC profiles and converted RGB images to CMYK, however when I go to use Acrobat Pro's preflight profile to flatten transparency and finalize the PDFX-1a, it reverts all the photo's back to RGB again. I am not sure why.

If anyone is interested in trying this PDF through their system I will be gald to send it to them. It is just a small ad and is only a few hundred KB.

thanks,
RG

 

[mattbeals]

You can send me the PDF, I'll tinker with it. There's something weird going on with Acrobat converting the images to RGB. That's not right.