Puppy Linux Discussion Forum Forum Index Puppy Linux Discussion Forum
Puppy HOME page : puppylinux.com
"THE" alternative forum : puppylinux.info
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

The time now is Fri 29 Jul 2016, 13:53
All times are UTC - 4
 Forum index » Advanced Topics » Hardware » Printers
Print quality variation between Slacko 5.3 and 5.6 [Solved]
Post new topic   Reply to topic View previous topic :: View next topic
Page 1 of 1 [3 Posts]  
Author Message
greengeek

Joined: 20 Jul 2010
Posts: 3963
Location: New Zealand

PostPosted: Mon 07 Sep 2015, 00:57    Post subject:  Print quality variation between Slacko 5.3 and 5.6 [Solved]
Subject description: Colour quality varies even using same driver
 

I use both Slacko 5.3 and Slacko 5.6 for printing colour documents to my Konica Minolta Magicolor 2300W printer but I get different quality results from each Slacko - even though I use the same driver and method of installation on both systems. I have made my tests using a live CD (no savefile) in each case.

I am hopeful someone can suggest what troubleshooting steps I can take to identify what is causing this different behaviour.

Here is the situation:
- I have no problems with the driver. It is a pet made available by rcrsn51 here and works perfectly on Slacko 5.3. I simply install the pet, use Cups admin page to discover the printer and it installs itself. Print quality is excellent for my needs.
- When I install this same pet on Slacko 5.6 I can install the printer (same method as above) and print quite happily but the text and images seem dark and "heavy". It looks as if way too much toner is being put on the page. It is so dark that images look as if they were taken without lighting.
- I tried using mtpaint to change the gamma value of an image and make it much much lighter before adding it to my document and printing it and was able to get reasonable results. The printed image looked much closer to how it should even though the onscreen image looked so washed out on screen that it appeared to have been taken in a snowstorm.

The pictures below offer comparisons to show what i am talking about:

The cups test page prints nicely from Slacko 5.3, but looks dark and lacking in halftones when printed from Slacko 5.6 (I have also included an image of a Brother 7820 black and white test page printed from Slacko 5.6 - it looks perfectly ok when printed on either system).

The dark image of my neice is showing how it printed from Slacko 5.6, even though it appeared normal onscreen. The lighter version of that image is showing how it printed out after I used mtpaint to lighten it so much that it was totally washed out on screen - but not so bad on the printer.

My interpretation of this is that there may be some sort of colour profile difference between the two systems affecting halftone printing - but I have no idea where to look. Unfortunately halftones are critical when printing most pictures.

There is a difference in Cups version - Slacko 5.3 is using cups 1.4.6 and Slacko 5.6 is using cups 1.4.8

Thanks in advance for any troubleshooting suggestions.
Slacko5.6_.jpg
 Description   Cups test page from Slacko 5.6 looks dull and heavy - almost as if it is smudged. Note the dark colour wheel.
 Filesize   32.62 KB
 Viewed   88 Time(s)

Slacko5.6_.jpg

Slacko5.3_.jpg
 Description   Cups test page looks great when printed from Slacko 5.3 - Note the gentle halftones in the colour wheel
 Filesize   33.57 KB
 Viewed   86 Time(s)

Slacko5.3_.jpg

Image_as_originally_printed_.jpg
 Description   This image was clear and perfect on screen but dark like this after printing
 Filesize   14.88 KB
 Viewed   82 Time(s)

Image_as_originally_printed_.jpg

Image_after_major_gamma_lightening.jpg
 Description   I used mtpaint to change the gamma, and made the image so light onscreen you could hardly see what it was.
 Filesize   29.35 KB
 Viewed   88 Time(s)

Image_after_major_gamma_lightening.jpg

Slacko56_7820comparison_.jpg
 Description   Halftones good on MFC7820 from Slacko 5.6 or Slacko 5.3. No variation
 Filesize   32.6 KB
 Viewed   93 Time(s)

Slacko56_7820comparison_.jpg


Last edited by greengeek on Tue 08 Sep 2015, 02:24; edited 1 time in total
Back to top
View user's profile Send private message 
greengeek

Joined: 20 Jul 2010
Posts: 3963
Location: New Zealand

PostPosted: Tue 08 Sep 2015, 02:20    Post subject:  

rcrsn51 offered the suggestion that Slacko 5.6 may have a newer Ghostscript than Slacko 5.3 and now be incompatible with the older Magicolor driver.
His suggestion of using
#gs -v
shows that:

Slacko 53 uses Ghostscript 8.15.4
Slacko 56 uses Ghostscript 9.05

First of all I decided to "upgrade" the old ghostscript on Slacko 5.3 by using a Ghostscript 9.05 pet referred to by rcrsn51 third of the way down this post and sure enough once that was loaded to slacko 5.3 it gave the same darkened colour wheel as I was getting on Slacko 5.6

Next I decided to try a "dirty" downgrade from version 9 to version 8 simply by grabbing some of the Ghostscript files from Slacko 5.3 and grafting them over part of the ghostscript files in Slacko 5.6

This worked and the colourwheel returns to normal and printing of my colour document is excellent. I don't recommend such an incomplete method of changing ghostscript - especially if you run a savefile which would retain the changes (which i don't) but anyway it has worked for me to get my printing done so I have made a pet which can be applied to Slacko 5.6 to overcome the dark gamma.

I have found some web info regarding how to change ghostscript gamma but it is more complex than I can understand at present. I am hopeful that I may eventually be able to return to Ghostscript 9.05 (or higher) and coach it to set it's gamma correctly.

The "Ghostscript_dirtydowngrade" pet is available here

*** WARNING *** it would probably be a bad idea to use my hackpet on a normal Puppy setup (with savefile) as it will render your ghostscript abnormal and hybrid. Only use this if you know how you can return your system to normal afterwards
.

Last edited by greengeek on Tue 08 Sep 2015, 15:48; edited 1 time in total
Back to top
View user's profile Send private message 
greengeek

Joined: 20 Jul 2010
Posts: 3963
Location: New Zealand

PostPosted: Tue 08 Sep 2015, 15:47    Post subject:  

rcrsn51 has highlighted this link as a possible source for a proper GS_8.15.4 package:
http://distro.ibiblio.org/quirky/pet_packages-wary5/ghostscript-8.15.4-w5c.pet
Back to top
View user's profile Send private message 
Display posts from previous:   Sort by:   
Page 1 of 1 [3 Posts]  
Post new topic   Reply to topic View previous topic :: View next topic
 Forum index » Advanced Topics » Hardware » Printers
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group
[ Time: 0.0322s ][ Queries: 12 (0.0029s) ][ GZIP on ]