Serhad Doken

Joint edge-directed interpolation and adaptive sharpening filter

In this paper, we present a joint filter that upsamples and adaptively sharpens a video/image simultaneously. The joint filter has been designed by combining a low complexity edge-directed interpolator with an adaptive Laplacian of Gaussian (LoG) filter. The joint filter yields sharp upsampled images, and is demonstrated to have lower computational complexity and similar visual quality when compared to using separate upsampling and sharpening filters.

An Improved Parametric Bit Rate Model for Frame-Level Rate Control in Video Coding

In a wireless video communication system, the video encoder needs to dynamically control the coding parameters based on the instantaneous video statistics and channel condition to achieve the best video quality. An accurate bit rate model can help the encoder to achieve accurate bit rate control and good rate-distortion (R-D) performance. In this paper, we improve the bit rate model by modeling the component of run-level mapping plus entropy coding as the process of choosing different codebooks for different quantized transform coefficients. We also compensate the mismatch between the true histogram and the assumed Laplacian distribution in a parametric model by utilizing the deviation of the estimation in previous frames.