Inconsistent Image Color in Custom Stamp Annotation after exporting to JSON.

[Gilbert Dimaano]

I notice that the color of the image changes when I export the annotation to Json format. 

To replicate;

1. Add the attached png file to a pdf
2. export the annotation to Json
3. import the generated Json file and see the image darken.

Attachment: agreedtoprioryearauditedaccounts_203506c8.png

[Venkada Subramanian Durai]

Hi Gilbert Dimaano,

Thank you for the update. We would like to confirm the behavior you are observing with the Syncfusion JavaScript PDF Viewer:

When we add the provided image as a Custom Stamp annotation through the UI, then export the annotations to JSON and import the same JSON back into the viewer, the imported stamp appears darker compared to the original stamp that was added initially.

Could you please confirm whether you are seeing the same behavior in your environment using Syncfusion JS PDF Viewer?

We have attached:

• A video demonstrating the issue, and
• A sample project that reproduces the behavior in our testing.

If you are not able to reproduce the same issue, please share the following so we can replicate your exact scenario and provide an accurate solution:
 

1. The annotation JSON you tested (exported JSON), and
2. A screen recording/video showing the steps to reproduce the issue using our attached sample project.

This will help us reproduce the exact issue and provide the most accurate resolution for the challenge you are facing with the PDF Viewer.

Sample project we have tested

Regards,
Venkada Subramanian D

Attachment: issuereplicateddemo_3284170c.zip

[Gilbert Dimaano]

Hi Venkada,

Yes, the image from the exported annotation appears to be darker than the original image.

[Venkada Subramanian Durai]

Hi Gilbert Dimaano,

Thank you for the update. We were able to reproduce the reported issue "After exporting and importing the provided image as a custom stamp in PDF Viewer, the custom stamp appears as dark". We suspect this to be a defect and will perform further analysis. We will update you with more details by April 13, 2026. 

Regards,
Venkada Subramanian D

[Venkada Subramanian Durai]

Hi Gilbert Dimaano,

Thank you for your patience. We were able to reproduce the reported issue: "After exporting and importing the provided image as a custom stamp, the custom stamp appears as dark" This issue originates from our PDF Library side. We have reported it to the respective team and will provide further details based on their response by April 14, 2026.

Regards,
Venkada Subramanian D

[Venkada Subramanian Durai]

Hi Gilbert Dimaano,

We apologize for the inconvenience caused. The PDF Library team is currently facing complexities in validating the reported issue with the provided stamp image. We will share further updates with you on April 16, 2026.

Thank you for your patience and understanding.

Regards,
Venkada Subramanian D

[Venkada Subramanian Durai]

Hi Gilbert Dimaano,

Thank you for your patience. We have confirmed the issue "After exporting and importing the provided image as a custom stamp, the custom stamp appears as dark" and logged it as a defect from PDF Library team.

 

We will include the fix in our immediate weekly release after 2026, Vol1 SP release.

 

Disclaimer: "Inclusion of this solution in the weekly release may change due to other factors including but not limited to QA checks and works reprioritization."

Regards,

Venkada Subramanian D

[Gilbert Dimaano]

Thanks for the update

[Venkada Subramanian Durai]

Hi Gilbert Dimaano,
 

Thank you for your patience. We have fixed the reported issue "After exporting and importing the provided image as a custom stamp in PDF Viewer, the custom stamp appears as dark" and the fix for the reported issue was included in our latest weekly release v33.2.4. Kindly upgrade to that version to get the issue resolved.

 

Root cause: During export annotation colorspace entry encoded string not properly converted into hexa decimal string.

 

 

Solution: ColorSpace encoded string entry properly handled while export into json format.
 

For Core, MVC and JS Packages:

Service side package

ASP.NET Core :      https://www.nuget.org/packages/Syncfusion.EJ2.PdfViewer.AspNet.Core      ASP.NET MVC:      https://www.nuget.org/packages/Syncfusion.EJ2.PdfViewer.AspNet.Mvc5/    https://www.nuget.org/packages/Syncfusion.EJ2.PdfViewer.AspNet.Mvc4/

 

CDN Links:

https://cdn.syncfusion.com/ej2/33.2.4/dist/ej2.min.js

https://cdn.syncfusion.com/ej2/33.2.4/material3.css

https://cdn.syncfusion.com/ej2/33.2.4/dist/ej2-pdfviewer-lib/pdfium.js

https://cdn.syncfusion.com/ej2/33.2.4/dist/ej2-pdfviewer-lib/pdfium.wasm

Regards,
Venkada Subramanian D