A Brightness Adjustment Method for MPEG-2 Compressed
Jun Jie Sun · 2006
A brightness adjustment special effects editing method in MPEG-2 compressed domain is proposed. The method is realized in the DCT domain of YUV color space without full frame decompression. Experimental results show that the visual quality of the edited video in the compressed domain is identical to the one edited in the uncompressed domain. I. INTRODUCTION Video special effects are needed to enhance the quality of the video production (1). Brightness adjustment has been focused on the producing of higher quality color reproduction. The object of brightness adjustment is to make the image lighter or darker overall (2)-(4). With the expansion of digital media, digital images or video frames are becoming widely available in MPEG-2 compressed formats. Therefore, for the conventional brightness adjusting method, the MPEG-2 compressed bitstreams are first decompressed into YUV sequences, and then transformed them to RGB representations. In the RGB space, brightness is adjusted by modifying the R , and G B channel components. In the nonlinear editing system, there is a special effect hardware processor, the input is the MPEG-2 bitstreams, so, if using spatial domain method, after the brightness adjusting, the representation are transformed into YUV presentation and recompressed using MPEG-2 standard. This process needs high computation complexity and large memory requirements. In order to overcome these disadvantages, a brightness adjustment method in DCT domain of its space for video editing is proposed in this paper. It is realized in the DCT domain of YUV space without full frame decompression. RGB