Tiff orthophoto property

[lidaky]

Hi,

I recently started using agisoft to process some aerial pictures. My input images are in the JPEG format, made up of three layers: RGB. When I come to export my orthophoto to a GeoTiff, the resulting file has 4 layers. Why it added a layer and how do I control that?
I want to do some image classification based on the RGB values of the orthophoto, therefore it is important to me to understand what these 4 layers means in respect to the 3 originals.
Thanks for the help.

[Wishgranter]

mostly is it the TRANSPARENCY layer - ALPHA channel, can open it in Photoshop ??

[lidaky]

YEs, got it.

the first 3 layers are RGB, the one I need.
So what id the transparency layer for?
Thanks for your answer
Simon

[Wishgranter]

Transparency international :-)

Sometimes it a very usefull feature for masking, but it could be deleted if not used = smaller file size..