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unidoc / unipdf

Golang PDF library for creating and processing PDF files (pure go)
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[BUG] digital signature with image appearance is not transparent, cover that text behind even thoug image is transparent #441

Closed MrFengJian closed 3 years ago

MrFengJian commented 3 years ago

Description

RT, while test example https://github.com/unidoc/unipdf-examples/blob/master/signatures/pdf_image_sign_appearance.go, I use a png image with transparent background and sign to a pdf, the signed pdf contains digital signature and image apearance but the image's background is not transparent and cover text like test_sign_stamped. at the same time, insert a png image with transparent background will not cover behind text eg:test_stamped.

Expected Behavior

digital signature with image has transparent background and show the text behind it normally

Actual Behavior

Steps to reproduce the behavior:

  1. choose a png image with transparent background and a pdf file
  2. pdf_image_sign_appearance.go
  3. check generated new pdf
  4. See error

Attachments

example image and pdf stamp3 test.pdf test_sign_stamped.pdf test_stamped.pdf

github-actions[bot] commented 3 years ago

Welcome! Thanks for posting your first issue. The way things work here is that while customer issues are prioritized, other issues go into our backlog where they are assessed and fitted into the roadmap when suitable. If you need to get this done, consider buying a license which also enables you to use it in your commercial products. More information can be found on https://unidoc.io/