Bug 145315 - PDF Export has artifacts on solid colored columns
Summary: PDF Export has artifacts on solid colored columns
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Calc (show other bugs)
Version:
(earliest affected)
7.0.4.2 release
Hardware: All All
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords: filter:pdf
Depends on:
Blocks: PDF-Export
  Show dependency treegraph
 
Reported: 2021-10-25 14:51 UTC by Jon R Kibler
Modified: 2023-04-10 13:47 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:


Attachments
The ODS file used to demonstrate this problem. (8.46 KB, application/vnd.oasis.opendocument.spreadsheet)
2021-10-25 14:51 UTC, Jon R Kibler
Details
Screenshot of PDF with lines, with most visible examples circled (241.70 KB, image/png)
2021-10-25 14:52 UTC, Jon R Kibler
Details
File created by Export as PDF -- has lines (8.64 KB, application/pdf)
2021-10-25 14:54 UTC, Jon R Kibler
Details
FIle created by Print->SaveAsPDF -- has no lines, but can't sign or secure it! (11.49 KB, application/pdf)
2021-10-25 14:55 UTC, Jon R Kibler
Details

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Description Jon R Kibler 2021-10-25 14:51:14 UTC
Created attachment 175910 [details]
The ODS file used to demonstrate this problem.

"File-->Export as PDF" is creating artifacts in the PDF file that do not exist in PDFs created by "Print-->Save as PDF" on macOS 10.14.6 (18G9323). Problem occurs in both normal and safe mode, and LO has full disk access enabled.

Specifically, if you color fill part of a column of merged cells, and have a different column color filled over a different range, the start and end of a range will leave fine white lines in the colored column with the shorter range. In general, the lighter the color of the overlapped column, the more prominent are the lines.

The file Annotated Screenshot contains an example with the more prominent lines circled.

Why not just print as PDF instead of exporting, if exporting is a problem? Because I can't sign or secure documents that are printed, and securing documents works on export. (Lines appear regardless of securing/signing.)

I have attached several files which illustrate this problem, including a sample ods file.
Comment 1 Jon R Kibler 2021-10-25 14:52:50 UTC
Created attachment 175912 [details]
Screenshot of PDF with lines, with most visible examples circled
Comment 2 Jon R Kibler 2021-10-25 14:54:15 UTC
Created attachment 175913 [details]
File created by Export as PDF -- has lines
Comment 3 Jon R Kibler 2021-10-25 14:55:38 UTC
Created attachment 175914 [details]
FIle created by Print->SaveAsPDF -- has no lines, but can't sign or secure it!
Comment 4 Alistair Saywell 2021-10-26 08:13:19 UTC
The lines in the pdf are not visible in Adobe Reader nor Edge browser. 
The lines in the pdf are visible in LibreOffice Draw up to a resolution of 1000% when they disappear.

They seem to be screen artefacts that are visible in some pdf viewers. 

See question https://ask.libreoffice.org/t/bug-in-export-so-can-anyone-recommend-a-program-to-sign-and-secure-a-pdf-file-created-by-print-saveaspdf/69699
Comment 5 Jon R Kibler 2021-10-27 00:51:37 UTC
Hi Alistair,

That is my question in Ask. :-)

As I recently updated there, on a Mac, I see the artifacts everywhere I try to view the PDF, including: FireFox, Brave (Chrome), PDF Expert, Preview, and Acrobat Reader.

Apparently it is a know issue, and not just in LO.

One suggestion I received may work:
a) Print in LO
b) Use 3rd party app to disable printing, editing, saving.
c) Sign in LO using the "sign existing PDF" capability I did not realize it had!

Thanks for your feedback!
JK
Comment 6 eisa01 2022-02-05 15:39:10 UTC
I can confirm

Version: 7.2.5.2 / LibreOffice Community
Build ID: 499f9727c189e6ef3471021d6132d4c694f357e5
CPU threads: 10; OS: Mac OS X 12.2; UI render: default; VCL: osx
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded
Comment 7 eisa01 2023-03-18 21:03:22 UTC
Still present, also on Linux

Artifacts shown in Draw, Firefox PDF viewer and Preview

Version: 7.0.4.2
Build ID: 00(Build:2)
CPU threads: 8; OS: Linux 5.10; UI render: default; VCL: x11
Locale: en-US (en_US.UTF-8); UI: en-US
Debian package version: 1:7.0.4-4+deb11u4
Calc: threaded

Version: 7.5.1.2 (AARCH64) / LibreOffice Community
Build ID: fcbaee479e84c6cd81291587d2ee68cba099e129
CPU threads: 10; OS: Mac OS X 13.2.1; UI render: default; VCL: osx
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded