Patent ID: 7443443
Filing Date: 2008-10-28
Classification: H04N

Abstract:
1. A method for generating an enhanced output image, comprising the steps of: acquiring an ambient image of a scene illuminated by ambient light; acquiring a flash image of the scene illuminated with a flash unit; determining a gradient flash image from the flash image; determining a gradient ambient image from the ambient image; combining the gradient flash image and the gradient ambient image to produce a combined gradient image; constructing an enhanced output image from the combined gradient image; in which the flash image is due to a flash radiance Φ scaled by a flash power P, and the ambient image is due to an ambient radiance α scaled by an exposure time E, and wherein flash gradients in the gradient flash image are ∇Φ and ambient gradients in the gradient ambient image are ∇α;and in which a coherence map for the gradient flash image and the gradient ambient image is