i want to make a layer mask in photoshop. after that i want to save the layer mask as a black and white JPEG. i want to use this black and white JPEG as a mask in photoscan. how do i do that?
After you have made your layer mask, CTRL/CMD + Left Click the layer mask to create a selection of the layer mask. Fill the selection with black (See Layer 2).
Then hide all layers with the graphic and then save as a jpeg (In my example hide Layer 1).
If-need-be you can reverse the selection by Select -> Inverse.
Here are the steps:
Now you can save it any way you like. Here are some screen captures for clues.