The pdf file that transformed the image does not perform the watermark function properly.
I attached the pdf file. Please check the watermark function test.
test version : aspose-pdf 19.2
Would you please share the definitions of the methods used in your code snippet i.e. makeImageStamp(), makeHeaderStamp, etc? We will test the scenario in our environment and address it accordingly. Also, please make sure to use Aspose.PDF for Java 21.10 before sharing the requested information.
Please try to replace the imageStamp.setBackground(true); with imageStamp.setBackground(false); and add the stamp again. In case you still face any issues, please let us know.