Abstract:

Video conferences,  a new type of conference in the internet age, have been widely used. Due to the influence of the external factors such as light, video acquisition device quality and network bandwidth, the quality of images of video conferences may deteriorate. Based on the multiple scale Retinex (MSR) algorithm, we divide the original images into illumination images of low frequency and high frequency reflection images by the bilateral filtering technique. And then the color constraints method and the gain compensation method are adopted to enhance the high frequency reflection images. Subjective experience and objective evaluation show that the improved algorithm enhances video images and preserves edge details when applied to soft video conferences, thus providing a better visual effect.

Key words: video conference;image enhancement;MSR;bilateral filtering;color constraints;gain compensation