The text on PDF documents looks distorted for some users

Technical Support
1

Which product are you using?
PDF.js Express Plus

PDF.js Express Version
8.4.0
Detailed description of issue
For some users the text looks distorted in PDF document, here is the screenshot:

unrendered_text
unrendered_text1069×527 315 KB

The technical specifications of the machines it happens to:
Windows 10 Business, 64-Bit OS // 1366 x 768 (Screen Res.) // Edge - Version 107.0.1418.62 // Chrome - Version 107.0.5304.108

Expected behaviour
The text on the PDF is completely rendered

Does your issue happen with every document, or just one?
It happens with every document, but only on the specific machines

Link to document
Any document

Code snippet
instance.UI.loadDocument(blob, {extension: ‘pdf’, filename: fileName});

3

Hi there,

Thank you for contacting pdf.js express forums,

I tested the pdf.js demo site PDF.js Viewer Demo | PDF.js Express on BrowserStack and was unable to reproduce:
Windows 10, Edge 107 (latest):

image
image1920×949 136 KB

Windows 10 Chrome 107 (latest):

image
image1920×955 111 KB

Note that the demo site is on 8.7

Can you try upgrading to the latest pdf.js express version and see if you can reproduce the issue?

Otherwise can you send the pdf file that is having the issues?

Thank you in advance.

Best regards,
Kevin Kim


Share how you are using PDF.js Express in your organization you could win a $500 Amazon gift card. All participants will receive 6 months of PDF.js Express+ for free. Learn more here

4

Hi Kevin,

We are having the same problem. Please see the attached PDF document on the current sample site with an example.

image
image1293×626 89.9 KB

image
image779×297 11.9 KB

sample.pdf (3.0 KB)

5

Hi fuse,

Please see this forum post: Choppy text rendered with Windows and Chrome - WebViewer - PDFTron Community

Best regards
Tyler Gordon
Web Development Support Engineer
PDFTron

6

Thank you, disabling accelerated 2d canvas flag fixed the problem for our users.

7

Thanks @tgordon.

Note this is also happening on windows 11.

Are there any plans/possible to address this issue? I.e. is it even possible for PDFJS to address this issue with chrome?

Thanks.

8

Hello fuse,

Unfortunately this is an issue with Chrome/Windows and the graphics drivers. You could possibly try recalculating the layout of the document to trigger a re-render: recalculateLayout(pagesToRecalculate)

Best regards,
Tyler Gordon
Web Development Support Engineer
PDFTron

9

Hey Tyler,

I just wanted to see if there was any change in the position of this?

Do you know of any other customers who have had success using recalculateLayout which resolved this problem?

Thanks.

10

Hi Fuse,

Unfortunately our investigation into this issue is ongoing.

We have had other customers try willReadFrequently: true on the iframe returned from pagesRendered but they have been hit-or-miss

Best regards,
Tyler Gordon