PDF miscoloration with transparent images overlayed over image (x-3 PDF)

[JimWelch]

• This doesn't happen on normal export to PDF.
• This doesn't happen on export to x-1 or x-4. 
• This only happens on exporting to x-3 PDF
• to the best of my testing ability

 

When you have an image background and then overlay a transparent image, the overlapping pixels become slightly miscolored. Not enough to jump out, but enough that if sent to a professional printer, it will be visible on the page. I've attached a quick af.pub file and a screenshot taken from my PDF viewer (chrome) of this afpub file exported to X-3 PDF standard.

 

To recreate

1) Create af.pub

2) Find a solid color image (doesn't need to be solid color, but easier to see this way)

3) Place solid color image on master page

4) In page mode, place an image that has transparency (PNG, etc.) over the background image.

5) Export to x-3:PDF standard, open and look at the overlayed image transparent pixels 

 

 

pdf_transparency_miscoloration_x3.zip

[Joachim_L]

On my screen the miscoloration is not visible, but with the color picker I measure a difference from C83 M53 inside the circle box to C84 M53 outside the circle box. The miscoloration vanishes completely, when I change the simulation profile in Acrobat to Coated FOGRA27

[JimWelch]

I also just noticed that any text there is also misaligned.

 

[JimWelch]

2 minutes ago, Joachim_L said:

On my screen the miscoloration is not visible, but with the color picker I measure a difference from C83 M53 inside the circle box to C84 M53 outside the circle box. The miscoloration vanishes completely, when I change the simulation profile in Acrobat to Coated FOGRA27

In my other document (not this test doc), I'm using CMYK/8 and SWOP (Coated) - required by printer and I can see the color difference on my screen when viewing the PDF output, but strangely only x-3. The x-1 and x-4 standards seem to work fine.