inconsistent swatch dithering problem

inconsistent swatch dithering problem

Post by Jeremy Pinkha » Sat, 15 Feb 1997 04:00:00

I have downloaded CLUT palettes of the 216 browser-safe colors from the
websites of David Siegel ( and Lynda Weinman
(, and Adobe itself, and none of these work
correctly in Photoshop -- the program they were designed for.  I am
using Photoshop 4.0 for Windows, and have set my monitor at 256 colors
to simplify designing web pages at this color depth.  I replace the
default Photoshop color palette with either of these downloaded color
tables, and all of the colors appear dithered.  The weirdest part is
that when I open the GIF file from which Siegel's color table was
created (via the IMAGE > MODE > COLOR TABLE command), almost all of the
colors in the swatch suddenly un-dither, except for the last 10 darkest
colors or so, which remain dithered.  This exact same palette appears
dithered each time I load Photoshop UNTIL I open the GIF.  Meanwhile,
the GIF itself is completely un-dithered.  Does anyone know what's going

-- Jeremy Pinkham


1. Inconsistent Print Quality: PSP problem maybe?

Problem: Duplicate copies of the same image, printed one immediately after
the other, are dissimilar.

Situation: PSP 7.04 under Windows 2000 Pro on a twin-processor PC with 512MB
ram and 65GB Hard disk space over three drives. No other applications
running. Canon S800 (not set as default printer) using oem inks and Canon
Photo Paper Pro, and using the latest driver v1.52

Description: I'm busy printing our wedding photos, and most of the time,
what I see on my monitor is almost exactly what I get in print, after
allowing for out-of-gamut colour shifts.

But having printed a single image (resized at 200ppi to A6 dimensions,
approx. 6" x 4") satisfactorily, and with the source image (but no other)
still on-screen, repeating the print command with no change to the printer
or any other settings produces a significantly darker image!

The only way around this, after several miss-prints, was to close down and
re-start PSP, re-open the image, and re-load the  printer profile I had
saved for this paper type and size.

For this familiar with the printer, having specified that I'm using Photo
Paper Pro, the only change to the standard Canon profile for this paper was
the definition of the A6 paper size.

The resulting print invariably matched the (excellent) first copy after this
process. However it is going to be tedious in the extreme to have to do this
repeatedly once I start receiving orders from family and other guests for
further copies of our wedding photos.


1. Has any one else come across this problem?
2. Do you think the problem might be with PSP, with Win2K, or with the Canon
printer driver? Instinctively I feel that it is a resources issue, hence the
effectiveness of closing down and re-starting PSP, but other views would
3 Do you have any ideas as to a solution or a work-around?

Regards & Thanks


2. RFI: Terrain/landform/world generation

3. Incredibly weird swatch problem!

4. Warning........Evidence Alert.............................................................................

5. To dither or not to dither


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9. jpeg dithering problem

10. Attn Porter re: problems with dithering

11. Browser-safe palette GIF dithering problem