[gs-bugs] [Bug 698724] - Ghostscript - Color conversion issue while converting PDF to jpg

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698724

Bug ID: 698724
Summary: Color conversion issue while converting PDF to jpg
Product: Ghostscript
Version: 9.18
Hardware: PC
OS: Windows 7
Status: UNCONFIRMED
Severity: normal
Priority: P4
Component: Color
Assignee: ***@artifex.com
Reporter: ***@interfaceinfosoft.com
QA Contact: gs-***@ghostscript.com
Word Size: ---

Created attachment 14439
--> http://bugs.ghostscript.com/attachment.cgi?id=14439&action=edit
This is a original PDF file which is tried to convert in jpg image, but geting
color difference.

I am seeing colors change when uploading files. I have attached a original PDF
(actually there is only one file allowed to attach so jpg file not added.). If
you look at them side-by-side, they show different colors. This is especially
apparent in the purple/orange/red brushstrokes at the top and bottom. One looks
significantly different from the other. The customer has noticed this with
other files as well. To find out color difference ColorPick Eyedropper tool is
used, it is a chrome plugin.I found that hex color difference in pdf and jpg
file(output file of following command).

following is command used :

"C:/Program Files (x86)/gs/gs9.18/bin/gswin32c" -q -dUseCropBox -dBATCH
-dDOINTERPOLATE -dNOPAUSE -dSAFER -dTextAlphaBits=4 -dGraphicsAlphaBits=4
-dPrinted=false -r150 -sDEVICE=jpeg -dJPEGQ=100 -sOutputFile=D:/img.jpg
D:/Harlem_GO_Eblast_#3-6.pdf -c quit

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698724

--- Comment #1 from Ken Sharp <***@artifex.com> ---
(In reply to santoshj from comment #0)

Post by b***@artifex.com
I am seeing colors change when uploading files. I have attached a original
PDF (actually there is only one file allowed to attach so jpg file not
added.).

You can only add one file at a time, you can add multiple times.

Post by b***@artifex.com
If you look at them side-by-side, they show different colors. This
is especially apparent in the purple/orange/red brushstrokes at the top and
bottom. One looks significantly different from the other. The customer has
noticed this with other files as well. To find out color difference
ColorPick Eyedropper tool is used, it is a chrome plugin.I found that hex
color difference in pdf and jpg file(output file of following command).

Your original PDF file is using a 4 channel ICCbased colour space, actually
several of them in fact, but basically CMYK. Your JPEG output is RGB. I'll
leave it to our colour expert to investigate this further, but the differences
do look pretty much like what I'd expect for a default conversion from CMYK to
RGB.

I imagine that at least one colour profile is required to get properly colour
managed output though.

[b***@artifex.com]

http://bugs.ghostscript.com/show_bug.cgi?id=698724

Michael Vrhel <***@artifex.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |WORKSFORME

--- Comment #2 from Michael Vrhel <***@artifex.com> ---
Color output is as it should be when going to an RGB device. Compared to AR
with sRGB output preview and the match is unbelievable good. Closing.