Re: Weird TIF won't import--16-bit greyscale

[Dov Isaacs <isaacs@xxxxxxxxx>]

16-bit grayscale or color files allow for 64k values for
each colorant as opposed to 256. Practically speaking, you
will not normally see any difference with the vast majority
of display and printing devices and techniques. 

The only file formats that support 16-bit per colorant images
are TIFF, PSD (native Photoshop), and RAW formats. The current
version of PDF (i.e., PDF 1.4) only supports a maximum of 
8-bit colorants. PostScript 3 supports a maximum of 12-bit 
colorants.

Although programs other than FrameMaker can indeed import or 
place such 16-bit per colorant images, in fact other than Photoshop,
they all convert such images to 8-bit per colorant images for both
preview and output.

I think you will see support for 12-bit and 16-bit per colorant
images increase as digital photography and the JPEG 2000 image
format becomes more pervasive since it conceivably preserves more
detail of the dynamic range of colorants of the "original" image
and may have some effect on output to CcMmYKk photo image printers.
For standard reproduction purposes today, you can readily get
away with converting to 8-bit per colorant images.

        - Dov


At 12/2/2002 07:00 AM, Sean Brierley wrote:
>I was given a TIF that will open in Photoshop but
>won't import into FrameMaker 5, 6, or 7. It's a 16-bit
>greyscale image, not an 8-bit one.
>
>Saving it as 8-bit, of course, works.
>
>But, I've never seen a 16-bit greyscale file. Is it
>really that many shades of grey? What makes these, how
>new are these, and why won't FrameMaker support it?
>
>Do formats other than TIF support 16-bit greyscale?
>Does PNG or BMP, par example?
>
>If you want a look-see, it's at
><http://www.pubsink.com/tif.zip>.
>
>I'd appreciate some info and thoughts on 16-bit
>greyscale images.
>
>Cheers,


** To unsubscribe, send a message to majordomo@omsys.com **
** with "unsubscribe framers" (no quotes) in the body.   **