mORMot Open Source

Genery

Member

Registered: 2016-11-14

Posts: 4

TPngImage on TPdfDocumentGDI.VCLCanvas

Hello,

Trying to draw partially transparent TPngImage on TPdfDocumentGDI.VCLCanvas using TPngImage.Draw. Transparent points are black in resulting PDF. What is the correct way to put partially transparent PNG to PDF?

-Dmitry

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,659

Website

Re: TPngImage on TPdfDocumentGDI.VCLCanvas

There is no transparency support for the bitmaps of the library, yet.
This is a hard-to-implement feature at PDF level.

The workaround is
- to make manual transparency (i.e. render the part of the page in a separated bitmap, then draw it on the pdf),
- or - even better - write the image as vectorial WMF/EMF instead of bitmap.

Genery

Member

Registered: 2016-11-14

Posts: 4

Re: TPngImage on TPdfDocumentGDI.VCLCanvas

I see. Thank you!