Block-based content-adaptive sharpness enhancement

Abstract

The contents of a video/TV sequence vary greatly not only across frames but also within the same frame. The existing peaking system like AutoTV where the peaking is made adaptive to the video contents and noise levels at a frame level is not sufficient for the high-end TV picture quality. This paper proposed a block-based content adaptive sharpness enhancement scheme that is able to adapt the peaking to the frame contents at a block level. In the proposed scheme, a frame is divided into a number of n × n blocks. Using some simple content-analysis techniques, each block is classified into categories with different characteristics to Human Visual System (HVS), such as the bright/dark block, the fine-details block, the strong-edge block, the smooth-area block, the skin/face block, etc. Appropriate processing is then applied to each block according to its category. The experimental results show that the proposed block-based content-adaptive peaking scheme achieves a better picture quality than the contentional peaking scheme.

Content dependent selection of image enhancement parameters for mobile displays

“…Effectiveness hue dependent colorfulness enhancement is illustrated in Figure ( 9). Figure 9 (a) represents original frame of T-DMB content.…”

“…Previous works on content dependent image enhancement can be found in [1][2][3][4][5][6][7][8][9]. They cover contrast enhancement [1][2][3][4][5][6][7], colorfulness control [3][4][5][6][7], sharpness enhancement [4,[8][9] and noise reduction [8].…”

“…They cover contrast enhancement [1][2][3][4][5][6][7], colorfulness control [3][4][5][6][7], sharpness enhancement [4,[8][9] and noise reduction [8]. In [4], genres of TV programs are classified.…”

“…Difference between original image and its filtered version is utilized as a measure of image details. In [9], a given frame is divided into non-overlapping blocks. Three types of blocks are identified based on strength of edges and luminance variations.…”