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Scribus => Beginner Talk => Topic started by: mike_tyson on May 20, 2013, 08:34:12 AM

Title: TIFF images after PDF export loose perceived color depth, details
Post by: mike_tyson on May 20, 2013, 08:34:12 AM
I have micropgraphs (fotographs taken through a microscope) in high resolution (3000x2000), 24 bit per pixel color depth. TIFF format.

I insert them into my scribus document, into rather small image frames, i.e. I think the images are downscaled quite heavily (which is intended, I want to preserve as much info as possible).

The goal is to generate PDF.

When I generate the PDF, the micrographs look very "flat", as if they have lost a lot of color, and fine details are not discernible anymore.

I do *not* think this is a problem with the micrographs themselves because when I downscale them in IrfanView with lanczos filter they still look very good with all color and details, even if I do extreme downscaling.

I tried a few diffferent parameters during the PDF export in scribus (lossless compression instead of lossy etc) to no effect.

Is there any way how I can retain full image quality? It is important to me that all the small details and color changes are still discernale in the PDF. Again, I do not think it is the downscaling per se, but I believe it must be related to Scribus because downscaling in other programs still retains the crucial information. Thanks.
Title: Re: TIFF images after PDF export loose perceived color depth, details
Post by: Nermander on May 20, 2013, 08:59:53 AM
Du you export PDF "For printer" or "For screen/web"?

"For printer" will generate CMYK PDF which if I understand right generally gives less saturated colors when shown on screen. Only use CMYK PDF ("For printer") if you explicitly knows that the printer needs a CMYK PDF.
Title: Re: TIFF images after PDF export loose perceived color depth, details
Post by: mike_tyson on May 20, 2013, 09:22:47 AM
Hi Nermander,

thanks! Yes that fixed it!

I was using for Printer because I thought this would be more true to the colors. But now that I switched to Screen it looks better at least on screen.
Title: Re: TIFF images after PDF export loose perceived color depth, details
Post by: Nermander on May 20, 2013, 12:20:49 PM
It's a very common problem, it has been suggested to rename those settings. When printing on a regular printer (color laser or inkjet) using "For screen/web" works fine, because those printers are usually designed to print RGB images.

So, use CMYK PDF only when explicitly asked for.