mORMot Open Source

fkaynakli

Member

Registered: 2011-06-14

Posts: 12

Transparent PNG demo

Hi;
I worked on adding transparent PNG to PDF for couple of days and I found that php library fpdf can do this. So I translated the php code to Delphi. You can download first demo application from here. I just worked on 32bits PNG images. The code uses a grayscale image for defining pixel transparency. But I have two problems:

• I can't extract Alpha channel from PNG directly. First load PNG image than I need to reload for extracting alpha. So it is not very effective.

• If I use a grayscale BMP as a mask image, it is ok. But if I use a grayscale PNG as a mask image, the are some problematic pixels. I think grayscale PNG loading function has a problem..

If someone can help I will be very pleased...

Last edited by fkaynakli (2011-09-03 10:01:56)

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,660

Website

Re: Transparent PNG demo

I'll take a look and check your code.

Thanks for your feedback!