How to export grayscale image as grayscale in PDF?

[feklee]

Steps:

1. Open the attached document in Xara Designer Pro X11. The included image has no color information. It is purely gray scale.
2. Export as PDF for commercial printing.
3. Extract the image from the PDF, e.g. using pdfimages: pdfimages grayscale.pdf img
4. Open the exported image in Xara or e.g. the Gimp.
5. With the color picker inspect the gray areas. They contain color information now. For example, what was #999999 in the original Xara document is now #8e8582.

The problem is that the colors do appear in print, as an undesired tint.

How do I properly export a PDF with all images as grayscale? In the actual document, only text has color.

[mwenz]

Xara products have no concept of grayscale. All gray images are converted to RGB, generally maintain appearance very well, and are exported to the appropriate profile upon PDF export. To an RGB profile, those gray images will/should maintain their RGB values, to CMYK they will be an appropriate CMYK mix.

This has been a long-standing request--to handle gray images.

One can use Acrobat to convert gray images to K only.

[feklee]

One can use Acrobat to convert gray images to K only.

Thanks for clarification! Any alternative to $$$ Acrobat? I’m fine with command line tools.

Update: Discovered a tool myself, A-PDF Black/White. The suggested use case is minimizing file size by converting PDF files to gray scale. Via settings it is possible to specify that only images, i.e. not text, should be converted. That seems to do the trick, although I haven’t yet verified the output thoroughly.

[mwenz]

Not that I am aware of. One version back of Acrobat is generally available from some (valid) retailers if one looks hard enough. Still there is a cost. But I cannot imagine doing commercial print without Acrobat. It's not like, at least on Windows, there is need to always update it. I know shops running version 9 still. In fact, version 9 is probably the last "near perfect" version

While I don't need to mix CMYK and gray images--if there is a gray image typically the whole thing is gray--unlike some other applications, I also cannot choose a non-CMYK or RGB ICC/ICM profile for PDF generation. So, for instance, I cannot choose a gray, or B/W, PDF profile from inside XDP. Nor, like other applications, is there an in-built option for choosing Grayscale, or B/W, as a valid output color model.

While the above doesn't help in your case of mixed gray images with colored elements that need to remain colored, it would be nice to at least have the option. I suspect the PDF library Xara uses has that option, just not as an option within Xara applications.

Mike

[Albacore]

Reimport your PDF into Xara and check your text values on grayscale as Xara likes to give Rich Black instead of a % of K. If it had done this just move the K slider one way and then adjust the K value to the % that you want and then resave the PDF then all is sorted.
I agree with Mike here, if you're going to send more than 1 file a month for print it is really worth your while to buy a copy of Acro Pro. For people who use print it's the best tool in your bag.

[mwenz]

Don't reimport the pdf to check the result...it will recovery it. If you want to check the output, upload a sample and I'll check in Acrobat.

I have long used A-PDF's various utilities. But not this particular one. To check that text remains text is easy enough. See if you can select the text after a conversion.

Mike

[Ron Duke]

Not that I am aware of. One version back of Acrobat is generally available from some (valid) retailers if one looks hard enough. Still there is a cost. But I cannot imagine doing commercial print without Acrobat. It's not like, at least on Windows, there is need to always update it. I know shops running version 9 still. In fact, version 9 is probably the last "near perfect" version

While I don't need to mix CMYK and gray images--if there is a gray image typically the whole thing is gray--unlike some other applications, I also cannot choose a non-CMYK or RGB ICC/ICM profile for PDF generation. So, for instance, I cannot choose a gray, or B/W, PDF profile from inside XDP. Nor, like other applications, is there an in-built option for choosing Grayscale, or B/W, as a valid output color model.

While the above doesn't help in your case of mixed gray images with colored elements that need to remain colored, it would be nice to at least have the option. I suspect the PDF library Xara uses has that option, just not as an option within Xara applications.

Mike

Mike,
How do I convert a color png to a grayscale png in Acrobat 9 Standard? I can't figure it out.

[Albacore]

Don't think Acro Pro could handle that Ron needs to be done in PS/Gimp. Mind you my copy of Acro Pro is old it's CS3 so don't know if you can with more recent versions or not and there could be now plugins available for the job.

[mwenz]

Mike,
How do I convert a color png to a grayscale png in Acrobat 9 Standard? I can't figure it out.

Hi Ron,

I don't know if one can with the Standard version or not. I'll post some screen shots in a bit if needed--and Adobe changed the look of some of the ways one goes about getting to the tools.

In short, if you have a tools panel, open it. Look for the Print Production tools. Convert Colors is the dialog you want. Let me know if you have that panel/dialog box.

Mike