Bug 692311

Summary:	Characters misrendered
Product:	GhostPCL	Reporter:	Marcos H. Woehrmann <marcos.woehrmann>
Component:	PCL interpreter	Assignee:	Henry Stiles <henry.stiles>
Status:	NOTIFIED FIXED
Severity:	normal
Priority:	P2
Version:	unspecified
Hardware:	PC
OS:	All
Customer:	661	Word Size:	---
Attachments:	error.png Patch for Bug692311

Description Marcos H. Woehrmann 2011-06-28 20:08:07 UTC

The customer reports that when the attached PCL file is rendered with GhostPCL some of the characters are rendered badly (see the attached PNG file).

Testing on various HP printers shows that the HP 5L, P3005, 4250, and 9050 print the file correctly but the 4500 and the 4600 do not (so monochrome printers print correctly and color printers do no).

Comment 2 Marcos H. Woehrmann 2011-06-28 20:10:00 UTC

Created attachment 7623 [details]
error.png

Comment 3 Shailesh Mistry 2011-07-06 20:16:06 UTC

Created attachment 7645 [details]
Patch for Bug692311

The input file consists of 3 raster blocks using adaptive compression and the error is due to the seed row from the first raster block affecting the next raster block.

The PCL5 Printer Language Technical Reference Manual Part 1 (October 1992), in section 15-27 Adaptive Compression Operation Hints states that in Delta Row Compression the seed row is initialized at the completion of each raster block.

The attached patch looks for a raster block ending in Delta Row Compression and zeros out the seed row.

Comment 4 Henry Stiles 2011-07-07 00:21:09 UTC

Fixed with http://git.ghostscript.com/?p=ghostpdl.git;a=commit;h=7531d50c