RE: Display device does not display 4-bit CMYK

Russell,

Things looked good until I tried the 1_2001.pdf test file.

The first problem is that the image is distorted and mostly missing.
When I look at the color_info structure, the depth is 32 (instead of 4).
The cause seems to be related to the changes that were made for the
'separation' mode'.  The routine display_put_params() calls
devn_put_params() which is setting the depth to 32.  This based upon
a calculation using the devn_params.bitspercomponent value.  This is
set to 8.  So I added the following line to display_put_params().

    }
    maxvalue = (1 << bpc) - 1;
+   ddev->devn_params.bitspercomponent = bpc;

    switch (ddev->nFormat & DISPLAY_ALPHA_MASK) {

Now the image is much better.  However the black text is missing.
I do not know why.  It is present in the 16#20101 mode.  It is present
with the pkmraw device (which is also a 4 bit CMYK device.)


Dan


-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Russell Lang
Sent: Wednesday, September 01, 2004 2:31 AM
To: [email protected]
Subject: [gs-code-review] Display device does not display 4-bit CMYK


Dan,

Log message:
Add support for 4-bit/pixel CMYK to the display device clients for 
Windows and gtk+.


Russell Lang                   [email protected]
Ghostgum Software Pty Ltd      http://www.ghostgum.com.au/