Stitching Grayscale Mode files in CS3

[sanking]

I do a lot of stitching of grayscale 16 bit files with Photoshop CS3, using the Automate>Photomerge command. This works great for me, with one exception, and that is the fact that during the merging Photoshop converts the Mode from Grayscale to RGB. The files are fairly large as grayscale (350 mb) and the conversion makes them well over a gig in size, which takes up a lot of unnecessary time in processing.

Is there a preference in CS3 that I can change to keep Photomerge from converting from Grayscale to RGB in merging the files?

Sandy King

[Brian_A]

I do a lot of stitching of grayscale 16 bit files with Photoshop CS3, using the Automate>Photomerge command. This works great for me, with one exception, and that is the fact that during the merging Photoshop converts the Mode from Grayscale to RGB. The files are fairly large as grayscale (350 mb) and the conversion makes them well over a gig in size, which takes up a lot of unnecessary time in processing.

Is there a preference in CS3 that I can change to keep Photomerge from converting from Grayscale to RGB in merging the files?

Sandy King

I'm not a fan of photomerge, but I couldn't find any options to change it. Have you tried PTGui or PTAssembler? 100% of the time I get better quality stitches and better quality blending with the other two programs. Just a thought.

[Jeremy Moore]

Is there a preference in CS3 that I can change to keep Photomerge from converting from Grayscale to RGB in merging the files?

Sandy King

Never found one either

[sanking]

I'm not a fan of photomerge, but I couldn't find any options to change it. Have you tried PTGui or PTAssembler? 100% of the time I get better quality stitches and better quality blending with the other two programs. Just a thought.

No, I have not tried PTGui or PTAssembler. Photomerge works perfectly for me with the exception of this problem so I have not seen the need to learn a new program.

One would think there would be some preference to change the default setting? Indeed, why would the default be to convert Mode Grayscale to RGB anyway?

Sandy King

[Brian_A]

No, I have not tried PTGui or PTAssembler. Photomerge works perfectly for me with the exception of this problem so I have not seen the need to learn a new program.

One would think there would be some preference to change the default setting? Indeed, why would the default be to convert Mode Grayscale to RGB anyway?

Sandy King

Sandy,

Can't say that I blame ya. If it ain't broke, don't fix it. That said, they probably convert it to RGB to help find stitching points and to blend it more accurately. "True" colors with "true" colors maybe. Something to do with the algorithm. I'm sure matching the same color edges to each other has something to do with it. That's my best guess, anyway.

-Brian

[Francisco Disilvestro]

Two ways of doing this,

A) Instead of photomerge, use auto-align and auto-blend. There is a short tutorial here

B) Modify the photomerge script (if you feel confortable with programming).

NOTE: I did do it and it worked stiching two grayscale 16 bit .psd files and it did not change to RGB. Anyway I have not tested it thorougly and I cannot guarantee it

Photoshop comes with a tool ExtendScriptToolkit2.exe found in (windows) \Program Files\Adobe\Adobe Utilities\ExtendScript Toolkit 2

Execute it and open the file Photomerge.jsx in (windows) \Program Files\Adobe\Adobe CS3\Presets\Scripts

Find (using edit->find & replace) RGB. You should get to a comment that says that some function works only in RGB, I think that it was left there from an older version of PS.

Press F3 (find next) untill you get a line of code that looks like:

stackDoc.changeMode(ChangeMode.RGB);

Put two slashes (//) at the begginig of the line (it will comment it)
//stackDoc.changeMode(ChangeMode.RGB);

Repeat the procedure because there are like three ocurrences of this command

Save the file & exit

Try photomerge

Important note: I recommend to backup the original photomerge.jsx file before modifying it, just in case something goes wrong

[sanking]

Thanks. I will try to modify the script.

Sandy King

Two ways of doing this,

A) Instead of photomerge, use auto-align and auto-blend. There is a short tutorial here

B) Modify the photomerge script (if you feel confortable with programming).