Assistance Needed: Strange Dot Pattern Issue in AirPrint Support for Printers

[sahayap]

Dear Michael,
I hope this email finds you in good health and spirits.

As you know we are developing the AirPrint support for our printers, its almost done, However, during the testing phase, we encountered an unusual problem that we are unable to resolve on our own.

The issue we are facing is that every printed line, including blank lines, contains additional dots in a line pattern. Despite thorough investigation, we have been unable to identify the root cause of this problem, leaving us somewhat perplexed.

To provide you with more context, here are the printing supported packages we have ported into our Embedded system:

• cups-2.4.5
  

• libcupsfilters-2.0b4
  

• libppd-2.0b4
  

• pappl-1.3.2
  

• pappl-retrofit-1.0b2
  

• openssl-1.1.1g
  

• qpdf-11.1.1
  

• poppler-21.05.0
  

• dbus-1.13.18
  

• lcms2.13.1
  

• openjpeg-2.3.0
  

• libpng1.6.35
  

In order to aid your investigation, we have attached the log files and a sample printout, which clearly exhibits the unexpected dot pattern issue.

logfile.txt

we kindly request your expert guidance to help us identify the root cause of this problem and suggest a solution to resolve it.

Thank you for your attention to this matter, and we look forward to your prompt assistance.

With warm regards,

Sahaya P

[sahayap]

Dear Michael,
I hope you are doing well.
I wanted to update you regarding the recent dot issues we encountered. After thorough investigation, we have successfully identified the root cause, which appears to be related to the libcupsfilters 8-bit gray to mono conversion.

Thank you.
With Best Regards,
Sahaya Darcius P