基于熵掩蔽的DCT域恰可察觉失真模型  

Just noticeable distortion model based on entropy masking in DCT domain

作　　者：骆琼华 王鸿奎 殷海兵 邢亚芬 LUO Qionghua;WANG Hongkui;YIN Haibing;XING Yafen(College of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310018,China)

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310018

出　　处：《电信科学》2023年第2期59-70,共12页Telecommunications Science

基　　金：国家自然科学基金资助项目(No.62202134,No.61972123,No.61931008,No.62031009);浙江省“尖兵”“领雁”研发攻关计划项目(No.2023C01149,No.2022C01068)。

摘　　要：为提高离散余弦变换(discrete cosine transform,DCT)域恰可察觉失真(just noticeable distortion,JND)模型阈值精度并避免跨域操作,将熵掩蔽效应引入DCT域JND模型。首先,从自由能理论和贝叶斯推理出发,设计基于DCT域纹理能量相似性的自回归模型模拟视觉感知过程中的自发预测行为;其次,探索视觉感知与预测残差的映射关系得到块级无序度,并将熵掩蔽效应建模为关于无序度的JND阈值调节因子;最后,结合空间对比敏感度函数、亮度自适应掩蔽以及对比度掩蔽,提出基于熵掩蔽的DCT域JND模型。与现有DCT域JND模型相比,所提模型所有运算均在DCT域执行,更高效简洁。主观、客观实验结果表明,所提模型在感知质量相同或更好的情况下,噪声污染图的平均峰值信噪比(peak signal-to-noise ratio,PSNR)值比其他4个JND对比模型低2.04 dB,更符合人眼视觉系统的感知特性。In order to improve the threshold accuracy of JND(just noticeable distortion)model in DCT(discrete co-sine transform)domain and avoid cross-domain operation,entropy masking effect was introduced into DCT-based JND model.Firstly,starting from the free-energy theory and the Bayesian inference,an autoregressive model based on texture-energy similarity in DCT domain was designed to simulate the spontaneous prediction behavior of visual perception.Secondly,the mapping relationship between visual perception and prediction residuals were explored to obtain the disorder intensity in block level.Thirdly,the entropy masking effect was modeled as a JND threshold modulation factor of disorder intensity.Finally,the JND model in DCT domain for the entropy masking was proposed by fusing the contrast sensitivity function,the luminance adaptive masking,the contrast masking.Compared with the existing JND model in DCT domain,the proposed model performed all operations in DCT domain,which was more efficient and concise.The subjective and objective experimental results indicate that the proposed JND model shows greater tolerance to distortion with better perceptual quality.

关 键 词：恰可察觉失真 人眼视觉系统 熵掩蔽效应 自由能理论 贝叶斯推理 

分 类 号：TN91[电子电信—通信与信息系统]