Adaptive guided image filtering for screen content coding

The capabilities of off-the-shelf consumer electronics are continuously increasing, making them interesting candidates to integrate into industrial visualization systems for reducing the cost of these systems or speed up development. However, in the context of video compression, hardware acceleration on consumer electronics is typically only provided for more common, consumer oriented YUV 4:2:0 profiles. Meanwhile, industrial applications often require YUV 4:4:4 formats due to synthetic visual data. Upscaling YUV 4:2:0 to YUV 4:4:4 using conventional filters results in visual artifacts, specifically for synthetic content. To improve the quality of the chroma components, this paper proposes to extend the well-known guided image filter through content-adaptive selection of the filter radius, and analyze different strategies for limiting complexity. This results in a 3.5 dB improvement of the chroma PSNR compared to conventional filters.