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Add image watermark to pdf, opacity is not working when hosting on linux environment

  1. When I am applying image watermark with opacity setting to a pdf file, it is normal if the program is hosting on windows environment, but not in linux environment.
  2. For GroupDocs.Viewer.UI: every time the host first start or restart, the first selected file that has more than 2 pages can not render all pages, it can just render 2 pages.
    viewer UI.png (370.9 KB)

License: GroupDocs.Total.NET OEM
Component Detail:
GroupDocs.Watermark 21.3.0
GroupDocs.Viewer.UI 3.1.5
GroupDocs.Viewer.UI.SelfHost.Api 3.1.11
GroupDocs.Viewer.UI.Api.Local.Storage 3.1.2
GroupDocs.Viewer.UI.Api.Local.Cache 3.1.3
.net 5
OS: windows 11、docker(5.0-focal)

on windows
sample-2022051118.514.pdf (1.1 MB)
viewer2.png (172.5 KB)

on docker
sample-2022051139.484.pdf (1.1 MB)
viewer1.jpg (192.2 KB)

I wrote a testing program, you can test it using swagger api to add watermark, and render it as png view by GroupDocs.Viewer.UI:
watermark-issue.zip (429.7 KB)


Could you please share a short video explaining the steps to reproduce the Watermark issue? Moreover, you can post all GroupDocs.Viewer for .NET API related issues in Viewer category.

Couldn’t you reproduce? Please try the steps below, the testing images is Logo.png under WatermarkImage folder.

1.Change to solution folder and run dotnet restore
2.Replace your license file under License folder
3.Change license path in Startup.cs
4.Build the docker image
5.Run docker container

dotnet restore
docker build -t watermark:v1 -f ./watermark-issue/Dockerfile .
docker run -d --name watermark-test -p 80:80 -v ${PWD}/watermark-issue/Files:/app/Files watermark:v1

6.Open swagger ui http://localhost/swagger and execute /pdfwatermark, this will add image watermark to sample.pdf and result file will be saved to sample-yyyyMMddss.fff.pdf. You can check this file is different from generating on windows environment.
7.Open Viewer UI http://localhost/viewer and select the sample-yyyyMMddss.fff.pdf, watermark is whole black background.
watermark video

I already posted to here


Thanks for the details. This issue is now under investigation with ticket ID WATERMARKNET-1368. You’ll be notified in case of any update.


Thank you. Any ETA for this issue? Or I need to create a paid support to get response quickly?


All free support tickets are assisted on first come first serve basis. However, if you want to expedite the process/resolution, you can create a paid support ticket.


Okay, I created a paid support ticket.

1 Like


This issue is already escalated to priority support.

The issues you have found earlier (filed as WATERMARKNET-1368) have been fixed in this update. This message was posted using Bugs notification tool by atir.tahir