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Conference hydra::amiga_v1

Title:AMIGA NOTES
Notice:Join us in the *NEW* conference - HYDRA::AMIGA_V2
Moderator:HYDRA::MOORE
Created:Sat Apr 26 1986
Last Modified:Wed Feb 05 1992
Last Successful Update:Fri Jun 06 1997
Number of topics:5378
Total number of notes:38326

5311.0. "ProWrite Graphics Printing" by LOSPED::MCGHIE (Thank Heaven for small Murphys !) Tue Dec 31 1991 06:56

    Hi,
    
    has anyone out there sucessfully printed something like a 16 grey scale
    graphic from within Prowrite ?
    
    I do get a picture printed, but the results are somewhat disappointing.
    
    I am using an LA75 in 'Other' mode, with the CBM1000 (whatever) printer
    driver and selecting the highest-density print mode available. I'm
    using Prowrite 3.2 (with the patches to take it to 3.2.2, thanks to
    however posted the patches !).
    
    Generally on screen it looks like Prowrite is reducing the display
    colours of the picture down to about 4. I am starting Prowrite with 16
    colours specified.
    
    Tonight I changed pallette before loading the picture and it didn't
    seem to colour reduce the picture as much on screen. Still the printed
    results were still not what I'd hoped.
    
    Any suggestions, comments etc. ?
    
    thanks
    	Mike
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5311.1ULTRA::KINDELBill Kindel @ LTN1Tue Dec 31 1991 09:1355
    Re .0:
    
>   Has anyone out there sucessfully printed something like a 16 grey scale
>   graphic from within Prowrite ?
>   
>   I do get a picture printed, but the results are somewhat disappointing.
    
    I haven't tried anything beyond simple line drawings, but I think there
    may be some mis-understanding of how ProWrite handles graphics.  The
    visual quality of the graphic is related to two factors, either of
    which can make for bad results.
    
    1.	When ProWrite imports bit-mapped graphics, there is often loss of
    	information as the LOWER resolution (ProWrite screen and graphic)
    	applies.  Printers usually have higher resolutions than the ProWrite
    	screen, so "jaggies" appear.  It COULD be that ProWrite 3.2's "High
    	Quality" mode can reclaim the lost information from the original
    	graphic data, if it's still around, but I don't know that it does.
    	I also don't know if ProWrite will properly render STRUCTURED
    	graphics (al� outline fonts) to retain maximum resolution.
    
    2.	ProWrite uses a dithering scheme to render color graphics.  It
    	knows that color printers have a VERY limited palette, so it does
    	color mixing to achieve colors that match the imported palette. 
    	Again, the limitations of the printer will cause information loss,
    	especially in the dynamics (brightness & saturation) of the image.

>   I am using an LA75 in 'Other' mode, with the CBM1000 (whatever) printer
>   driver and selecting the highest-density print mode available. I'm
>   using Prowrite 3.2 (with the patches to take it to 3.2.2, thanks to
>   however posted the patches !).

    I'm also grateful for the 3.2.2 patches.
    
>   Generally on screen it looks like Prowrite is reducing the display
>   colours of the picture down to about 4. I am starting Prowrite with 16
>   colours specified.

    ProWrite does its most serious dithering at print time.  Since ProWrite
    uses a non-HAM screen, it needs to map the image into its palette
    without stomping on the colors used for text and its own display.  It's
    quite likely that ProWrite reserves a handful of colors for included
    graphics and does the best it can within that constraint.
    
>   Tonight I changed pallette before loading the picture and it didn't
>   seem to colour reduce the picture as much on screen. Still the printed
>   results were still not what I'd hoped.
    
    If you load the same image into Deluxe Paint (or whatever) and set its
    palette for the 16 shades of grey.  When you print, what do you get? 
    That's the upper limit of what you can expect from ProWrite.  You're
    constrained by a number of PHYSICAL limitations as much as anything. 
    Consider how many printer pixels will be available to represent each
    screen pixel.  Then consider how 16 shades of grey could be represented
    within that small number of dots.  You're asking a LOT.
5311.2NOTIBM::MCGHIEThank Heaven for small Murphys !Wed Jan 01 1992 07:007
    Thanks for the in depth reply Bill.
    
    I'll try printing the same graphic using some other mechanism and see
    what the results are like.
    
    thanks
    	Mike
5311.3Are you specifying 4096 color printing?TFH::KIRKa simple songFri Jan 03 1992 13:3923
re: Note 5311.0 by Mike "Thank Heaven for small Murphys !" 

>                        -< ProWrite Graphics Printing >-

>    Generally on screen it looks like Prowrite is reducing the display
>    colours of the picture down to about 4. I am starting Prowrite with 16
>    colours specified.
    
>    Any suggestions, comments etc. ?
    
The screen setup is for display only and usually bears little resemblance to 
graphics that get printed.  8 or 16 color screen shouldn't affect what gets 
printed.

When the new ProWrite prints, you can specify 8, 64, or 4096 color printing.

Only 4096 color printing will generate 16 grey levels.
(64 color will generate 4 grey levels, 8 color reduces you to black, white, 
plus the primary additive and subtractive colors.)

Cheers,

Jim
5311.4LOSPED::MCGHIEThank Heaven for small Murphys !Fri Jan 03 1992 21:1611
>>>Only 4096 color printing will generate 16 grey levels.
>>>(64 color will generate 4 grey levels, 8 color reduces you to black, white, 
>>>plus the primary additive and subtractive colors.)

    Thanks for that, I'll try printing the graphic again and set what
    results I get. I did try printing another picture from within Prowrite
    last night and as it was 256/ham colours I selected 4096 in the print
    requestor. The output was quite reasonable.
    
    Thanks
    	Mike