Filtering noise in progressive stochastic ray tracing - Four optimizations to improve speed and robustness

We present an improved version of a state-of-the-art noise reduction technique for progressive stochastic rendering. Our additions make the method significantly faster at the cost of an acceptable loss in quality. Additionally, we improve the robustness of the method in the presence of difficult features like glossy reflection, caustics, and antialiased edges. We show with visual and numerical comparisons that our extensions improve the overall performance of the original approach and make it more broadly applicable.