{'fraction_non_alphanumeric': 0.030632411067193676, 'fraction_numerical': 0.017786561264822136, 'mean_word_length': 4.72316384180791, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Intra prediction method based on the linear relationship between the channels for YUV 4∶2∶0 intra coding

In general, the transformation from RGB to YUV color space reduces the correlation between the channels. But some sources in the YUV space still have strong inter-channel correlation, which can be modeled as a linear function. Based on this linear model, we propose a new intra chrominance prediction method for color image compression in YUV 4∶2∶0 color space. A block of chrominance pixels to be encoded is predicted from the reconstructed luminance signal using the proposed prediction scheme and the residual is encoded based on the H.264/AVC. Also, an implicit prediction method that can obviate the transmission of side information is proposed. The experimental results show that there are about 0.35∼1.0dB gains for the luminance (Y) channel, and 0.5∼3.0dB gains for the chrominance (Cb or Cr) channels at the medium to high bit-rates. The proposed method also shows some gains at the low bit-rates.