Image quality assessment via colour information fluctuation

Image quality is an important metric for measuring multimedia services; thus, analysing image quality accurately has high practicability. The existing image quality assessment (IQA) methods mainly focus on grey information, which underutilize the colour information. In this paper, a new IQA method is proposed to make full use of colour information. The method calculates the colour information fluctuation (CF) around each pixel in different detection directions, and obtain CF maps (CFMs). Meanwhile, the greyscale fluctuations (GFs) are analysed to extract GF maps (GFMs). Based on CFMs and GFMS, the direction information is calculated to form CF direction map (CFD) and GF direction map (GFD). After that, the histogram-based features are extracted from CFMs, GFMs, CFDs and GFDs. Finally, different features are combined to measure quality variations comprehensively. The performance comparisons demonstrate the proposed method is competitive with prevalent methods, and is suitable for both natural image and screen content image.