Bug 27297 - Transparency for indexed PNGs
Summary: Transparency for indexed PNGs
Status: NEW
Alias: None
Product: Batik - Now in Jira
Classification: Unclassified
Component: SVG Rasterizer (show other bugs)
Version: 1.5
Hardware: All All
: P3 minor
Target Milestone: ---
Assignee: Batik Developer's Mailing list
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2004-02-27 17:31 UTC by Venkatesh Narayanan
Modified: 2006-07-31 07:18 UTC (History)
2 users (show)


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Description Venkatesh Narayanan 2004-02-27 17:31:14 UTC 
In 1.5 svgrasterizer, when outputting PNG images, transparent PNGs are created
only for 24-bit PNGs.For cases where size of output image is a concern, it would
be nice if transparent images were created for indexed (8-, 4-, 2-, 1- bit) PNGs
as well.
I believe Thomas DeWeese is the person who wrote PNG encoding code.
Comment 1 Thomas Deweese 2005-03-22 12:16:18 UTC 
Reassigning all open bugs to the development list.
Sorry for the mass mailing.
Comment 2 Thoralf Rickert 2006-07-31 14:18:31 UTC 
The problem is that the call to 
org.apache.batik.ext.awt.image.rendered.IndexImage.getIndexedImage
(BufferedImage,nColors) returns an indexed image without transparency. The 
method ignores the alpha channel during calculation of indexed colors.

I think this isn't an enhancement - this is a bug.