Gradient domain color restoration of clipped highlights

Sensor clipping destroys the hue of colored highlight regions by misrepresenting the relative magnitude of the color channels. This becomes particularly noticeable in regions with brightly colored light sources or specularities. We present a simple yet effective gradient-space color restoration algorithm for recovering the hue in such image regions. First, we estimate a smooth distribution of the hue of the affected region from information at its boundary. We combine this hue estimate with gradient information from channels unaffected by clipping to restore clipped color channels.