Guided Linear Upsampling
This work addresses efficiency and quality issues in image upsampling for applications like interactive editing and real-time video processing, representing an incremental improvement over existing guided upsampling techniques.
The paper tackles the problem of accelerating high-resolution image processing by proposing a guided linear upsampling method that represents each high-resolution pixel as an optimized linear interpolation of two low-resolution pixels, achieving better detail preservation and artifact suppression compared to previous methods.
Guided upsampling is an effective approach for accelerating high-resolution image processing. In this paper, we propose a simple yet effective guided upsampling method. Each pixel in the high-resolution image is represented as a linear interpolation of two low-resolution pixels, whose indices and weights are optimized to minimize the upsampling error. The downsampling can be jointly optimized in order to prevent missing small isolated regions. Our method can be derived from the color line model and local color transformations. Compared to previous methods, our method can better preserve detail effects while suppressing artifacts such as bleeding and blurring. It is efficient, easy to implement, and free of sensitive parameters. We evaluate the proposed method with a wide range of image operators, and show its advantages through quantitative and qualitative analysis. We demonstrate the advantages of our method for both interactive image editing and real-time high-resolution video processing. In particular, for interactive editing, the joint optimization can be precomputed, thus allowing for instant feedback without hardware acceleration.