CMYK TIFFs with Alpha channel masks

I'm trying to read some CMYK TIFF images with alpha channel masks.  As
I understand it:

1) Since the CMYK data occupies the entire PixelPacket, the alpha
   channel data is stored out of band.

2) I call GetIndexes() to get back a pointer to the alpha channel
   data.

3) The alpha data is stored one quantum/pixel, regardless of the bit
   depth of the image, etc.

Are these correct?  Because the data I'm seeing from GetIndexes()
doesn't look right, and I'm getting "Bad Pointer" errors in trying to
access all of it.


Thanks very much,


-pd


-- 
--------
    Peter Davis                               Pageflex Inc
    617-520-8345                          215 First Street
    617-868-0784 (FAX)                 Cambridge, MA 02142
    [email protected]      http://www.pageflexinc.com


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