Video enhancement based on saturation adjustment and contrast enhancement

We propose a new algorithm to improve the visual appearance of compressed videos, which are derived and reproduced from old films. The new technique is especially useful in handling the digitized old films of digital archives. Two main techniques, saturation adjustment and contrast enhancement, are implemented to improve the chrominance and luminance of video frames on HSL color space. For contrast enhancement, we use weighted histogram separation (WHS) to improve the luminance. Subsequently, the saturation ratio transfer function is proposed to adjust the saturation level of every frame. Furthermore, the new calculation method for the error of inter-frame is adopted to avoid the incorrectly enhanced result and the intensive computation consumed in motion estimation. The experimental results demonstrate that the proposed method outperforms the existing approaches in terms of video quality.