Colorspace invalid error with cups

Question

I am attempting to print a PDF, but CUPS is giving me an error stating:

"(urftopdf) die(Invalid ColorSpace, only RGB 24BIT type 1 is supported) [Success]"

I'm not really even sure what this means. Despite the fact it says "success", nothing prints. I'm sending the PDF file via airprint from my iPhone (other PDFs and other things work, so I know that it's implemented correctly.

Answer 1

It means that CUPS tried to use the program urftopdf to convert your file into a printable format, and that program failed because it can only handle the "RGB 24BIT" color encoding. UNIRAST (image/urf) is the format airprint uses, and the converter is reverse engineered. So unless someone reverse engineers the other color encodings and updates urdtopdf, the solution is to avoid airprint, and try to print the PDF file in a more direct way that can handle other color encodings (by transferring it to a PC, installing something on your iPhone that directly uses CUPS if such a thing exists, or whatever).

Answer 2

I'd like to share that I was able to print from my iPhone 7 on my printer (Canon ip2700 series) as of March 2017.

I found myself having the exact same problem and error message displayed on the CUPS web interface, under the Jobs panel.

Problem

The problem was that during configuration of my printer on the CUPS web interface, I set the default settings to print on grayscale, which urftopdf does not support.

Fix

Instead, set the default setting to print on rgb and it should be fine.

1. Using the web interface, under the Printers tab, select the printer you are fixing.
2. On the second checkbox (operations), select Set Default Options.
3. On Color Model, select RGB instead of grayscale.
4. Click Set Default Options.

Other references

For those of you attempting to run AirPrint on a linux server or a Raspberry Pi, this AirPrint Guide and subsequent Fix by Eric Sarjeant in 2012 still works as of March 2017 with the commands that he listed as it is.