reduce 16 bits to 8 bits

[ps...@emmet.com]

for some reason one of my 16 bit tif pix cannot be reduced to 8 bits!
the 8 bit option is greyed out. i tried converting it to a psd but the
8 bit option was still greyed out. any suggestions how to get the 8
bit option back?

tia

steve

[ps...@emmet.com]

unfortunately saving to 8 bits is not an option for any file that is
16 bits in photoshop cs4

steve

On Sat, 06 Jun 2009 20:06:29 -0500, Joel <Jo...@NoSpam.com> wrote:

> I don't know what you are looking at, but if you want 8-bit then just save
>to JPG then you have no other option but 8-bit
>
>> steve

[Fred]

> unfortunately saving to 8 bits is not an option for any file that is
> 16 bits in photoshop cs4
>

Try File>Save for web & devices, select JPG and the compression you want
Strange though!

[botox]

Have you checked the mode: are you sure this is a 16 bit RGB image?

[ps...@emmet.com]

fabulous idea ... but ..."not enough scratch memory" ... and i have a
scratch memory only 160 gig hard drive! the image is only 350 megs or
so ... strange ...

but nice idea :-) ...

steve

[ps...@emmet.com]

yep ... one can see the /16 in the top of the image

steve

On Sun, 7 Jun 2009 05:12:58 -0700, "botox" <fac...@hotmail.com>
wrote:

[Mike Russell]

On Sun, 07 Jun 2009 21:24:39 -0700, ps...@emmet.com wrote:

> only 160 gig hard drive! the image is only 350 megs or
> so ... strange ...

350 megs is a very large image. So it's not surprising that you are
running out of memory and scratch space.

Make the image smaller. Unless you are using a view camera with a scanning
back, or a composite image made up of a dozen or so smaller images, your
image is larger than you need it to be.
--
Mike Russell - http://www.curvemeister.com

[Mike Russell]

This actually might be related to the color mode. I can recreate this
behavior if I convert a 16 bit image to multichannel mode. 8 bits is
greyed out, and it is not possible to select 8 bit mode until I convert to
another mode such as Lab, RGB, or CMYK.

[Kabuki]

"Mike Russell" <grou...@MOVEcurvemeister.com> wrote in message
news:esy825ljicl3$.dlg@mike.curvemeister.com...

well I was only guessing but
seems I was not far from the solution
of course the usuals chimed in to tell me I was wrong

[Mike Russell]

On Tue, 9 Jun 2009 18:01:38 -0400, Kabuki wrote:

> well I was only guessing but
> seems I was not far from the solution
> of course the usuals chimed in to tell me I was wrong

NO good deed goes unpunished, LOL.
OTOH, we may both be wrong...

[ps...@emmet.com]

according cs4 it is in rgb mode ...i can send a screen shot
documenting this ...

steve

[ps...@emmet.com]

shangara was kind enough to post a work around ...i created an 8 bit
blank image of the same dimensions ...copied the 16 bit into it, ok'ed
the conversion to 8 bits and it was a done deal ...

but ...i still wonder why the conversion of the original image was
greyed out ...oh well ...

steve

[Rob]

If that worked then try a "save as" of your tiff file close and reopen
it and see what happens.

In the past I have had problems with tiff files that were not correctly
recognised in PShop 7.0? They were scanned slide images from the Nikon
film scanner.

[Mike Russell]

On Tue, 09 Jun 2009 21:43:02 -0700, ps...@emmet.com wrote:

> according cs4 it is in rgb mode ...i can send a screen shot
> documenting this ...

Curiouser and curiouser. If you can get the size down to a few megs or so,
email me a copy - mike at curvemeister.com and I'll take a look.

[ps...@emmet.com]

the problem with that image is that it is about 400 megs :-) ... and
... as it is 16 bits i can't reduce it to a jpg :-) ...

but shangara's suggestion to copy it to a same size 8 bit image worked
... strange ...

steve

[Mike Russell]

On Wed, 10 Jun 2009 22:55:00 -0700, ps...@emmet.com wrote:

> the problem with that image is that it is about 400 megs :-) ... and
> ... as it is 16 bits i can't reduce it to a jpg :-) ...

Crop a section of the image and see if it has the same problem. If 8 bits
is still grayed out, you can email it to me. If it is not, that's a clue
that it's some sort of image size related issue, and that will also shed
some light on the problem.

> but shangara's suggestion to copy it to a same size 8 bit image worked
> ... strange ...

Definitely.