Bug 692224

Summary:	Issues with transparency at high resolutions
Product:	Ghostscript	Reporter:	Marcos H. Woehrmann <marcos.woehrmann>
Component:	Graphics Library	Assignee:	Ray Johnston <ray.johnston>
Status:	NOTIFIED FIXED
Severity:	normal	CC:	JohnsonE, mike
Priority:	P2
Version:	master
Hardware:	PC
OS:	All
Customer:	536	Word Size:	---

Description Marcos H. Woehrmann 2011-05-23 09:37:20 UTC

The customer reports and I've verified that Ghostscript 9.02 and head (b7d52f725a7c4ef939469f757687a86252fade9c) produce a PNG file with a correct transparent background at 150 dpi but not at 300 dpi.

The command lines I'm using for testing:

  bin/gs -r150 -sDEVICE=pngalpha -o test150.png line_demo.pdf

and

  bin/gs -r300 -sDEVICE=pngalpha -o test300.png line_demo.pdf

Comment 2 Michael Vrhel 2011-09-10 16:11:55 UTC

This has actually nothing to do with transparency but is a clist issue (the file contains no transparency and the pdf14 device is not installed).  The pngalpha devices alpha channel appears is not being handled properly during clist writing.
Assigning to Ray to look at.

Comment 3 Michael Vrhel 2011-10-05 07:19:09 UTC

*** Bug 691372 has been marked as a duplicate of this bug. ***

Comment 4 Ray Johnston 2011-10-11 16:21:43 UTC

Fixed with commit 5ce12e8

Handle transparent background with custom fillpage in pngalpha