change depth from 32bit to 8bit

[fatysekDesign]

Hey.

is there a simple way to change depth of image. I'm makking TMO filter plugin, and operate on 32bit image, laast operation i need to convert to 8 bit.

Is there any function fot that?

thanks.

[Tom Ruark]

Not from a filter plug-in. You would have to do an automation plug-in that "listens" for your filter event to complete and then the automation plug-in can 'post process' your filter results and change the document to 8 bit. See the Listener automation example in the SDK.

[Chris Cox]

Just create a filter to do the TMO in 32 bit - outputting your result in gamma 1.0, 32 bit values ranged 0 ... 1.0.

Then afterwards convert the document to 8 bit with a NULL tone mapping (Exposure/Gamma at 0/1).

[fatysekDesign]

when I do conversion from 32 to 8, Photoshop running the HDR Tonning, what is wrong. How do I make it will not turn on?

[Chris Cox]

Yes, Photoshop has to do some toning, so set it to do a NULL conversion: exposure & gamma with settings of 0 exposure, and a gamma of 1.0.

[fatysekDesign]

"Just create a filter to do the TMO in 32 bit - outputting your result in gamma 1.0, 32 bit values ranged 0 ... 1.0."

Hiw to output result with gamma 1.0  and exposure with 0.0? is there any function for that?

[Chris Cox]

Sigh.  32 bit/channel data is always gamma 1.0. YOUR TMO code needs to output the data still as gamma 1.0, with a range of 0 to 1.0.

Then you use a script or an automation plugin to convert the 32 bit toned document to 8 bits/channel, using the option for exposure & Gamma.

[fatysekDesign]

Right, now I understand, but how to output data wich hamma 1.0? is there ny function for that?

[Chris Cox]

Again, there is no function for that -- it's something you have to do in your TMO.

You are starting with gamma 1.0 data, and should output gamma 1.0 data from the TMO.

[fatysekDesign]

and when I output data with gamma 1.0, and after this i convert to 8bit in photoshop, then HDR Tune dont start?