warn us when converting 24 bit images to 8 bit

[dhillier]

If Office Picture Manager is used to rotate 24 bit TIFF images 90 degrees the
resulting rotated pictures are 8 bit and there is no warning about the
conversion that I could see. That can wipe out expensive images in a fairly
suble way. I only lost about 200 before discovering the problem.

A second consequence was that when the rotated images were opened in Adobe
Photoshop CS, a warning appeared about possibly incomplete or truncated
files. Not a problem except that it interrupts batch processing.

 

[Bob I]

Humm, couldn't replicate that here. 24 bit color tif file rotate 90
degrees and saved = a 90 degree rotation of the original file. Opened
and viewed in Kodak Imaging and verified. Something wrong with your
setup or some type of compression / file size reduction was attempted by
the operator.

 

[dhillier]

Sorry, I mislead you. The images I was rotating were 48 bit (16
bit/channel), and the rotation left me with 24 bit (8 bit/channel). Have now
confirmed the problem with 48 bit images from a second source.

 

[Bob I]

Suggest using a graphics program designed for that particular format. 48
bit ".tif" is one of the less "common" formats, and as such probably
only views as 24 bit in manager too.