ISP bias-compensating noise reduction systems and methods

Systems and methods are provided for compensating bias introduced from various image signal processors (ISP) or ISP components while effectively reducing noise. An ISP stage such as spatial noise filtering, high dynamic range (HDR) interpolation, and demosaicking among others, often results in various types of biases and artifacts being introduced in the output frame. The methods and systems of this disclosure employ a convex combination of multiple input frames or blocks of pixels, to effectively reduce bias from a spatial noise filter, a debayer unit, or other ISP components, thereby providing improved spatiotemporal noise reduction solutions.