A technique for producing a foreground mask from a digital image is based on receiving two digital images, wherein a first digital image is derived from a first original scene image including a foreground photographed against a background having arbitrary and unknown content matter, and a second digital image is derived from a second original scene image including substantially the same background but without the foreground. The second digital image is automatically aligned to the first digital image without user intervention to generate an aligned digital image including the background without the foreground. Then, using the first digital image and the aligned digital image, a foreground mask is produced relating to the spatial regions in the first digital image pertaining to the foreground, whereby the foreground mask is subsequently used to generate a composite digital image.