Making masks with photoshop then importing into photoscan

[JeffNielson]

I am using a green screen to take JPG images with a fixed camera and a turntable.  For whatever reason I can't get photoscan to use a standard JPG photo as a mask with good results.  So, I turned to Photoshop where I can create a macro that quickly masks out the background and creates an alpha channel.  The problem is this... I'm not sure what is the best way to incorporate the photoshop mask.  I can't embed it in the jpg without altering the exif data, right?  I also don't want photoshop to re compress my JPG introducing more artifact.  I could use the RAW data but that would be new to me, and I still don't know what format Photoscan would want the file in.  I tried importing the PSD file but PhotoScan didn't want to do that. 

So, the question is, what works and what works well?

I know this is a simple question, but I couldn't find anything in the manual about good ways to do this and I couldn't find anything by searching.

Thanks a lot.

[bigben]

Save as TIFF (LZW compress to save space)   If you're coming from RAW images you'll avoid JPEG artefacts

Tools > Import Masks > From alpha.

[driftertravel]

There are programs to re-inject exif data into images processed in photoshop, but I find that just exporting masks from photoshop and keepnig the originals as is works fine and is faster.

[bigben]

Be careful: if you save as TIFF from photoshop, you will loose position information stored in the EXIF (if any)

Which position information?  Saving as TIFF shouldn't lose any metadata. I've never lost any GPS info changing file formats. e.g. attached metadata in TIFF saved from an iPhone JPEG