一种用于高动态图像的自适应编码方法的改进研究

A Kind of Adaptive Coding Method for High Dynamic Image Improvement Research

高动态图像亮度变化范围较大,当前编码方法采用DCT技术描述高动态图像信号的变换,无法准确描述图像细节、频率突变的高动态图像信号,导致编码后图像的极亮和极暗区域可视性低、细节不丰富。提出一种新的用于高动态图像的自适应编码方法,分析了高动态图像编码过程,通过小波变换实现高动态图像信号描述形式的自适应变换,对高动态图像进行多尺度分解,获取不同尺度的高动态图像信息,得到子带图像;对各子带图像的小波系数进行量化,以达到提高图像码率的目的。在此基础上,选用Log Luv(TIFF)编码方法,对高动态图像信息数据间的统计相关性进行滤除,完成高动态图像的自适应编码。实验结果表明,采用所提方法对高动态图像进行编码后,得到的图像质量较高;且在编码效率较低的情况下,仍能保持较高的图像质量,编码性能明显优于预测编码方法。

High dynamic image brightness range is larger,the current coding method using DCT high technical description of dynamic image signal transformation,unable to accurately describe the image details,high frequency mutation of dynamic image signal,cause the encoded image is very bright and very dark area of low visibility,do not have much details. Presents a new adaptive coding method for high dynamic image,analyzes the dynamic image coding process,highly dynamic image signal by wavelet transform is described in the form of adaptive transform,multi-scale decomposition of high dynamic image,obtain the different scales of high dynamic image information,get subband images,the wavelet coefficients of each subband image quantification,to achieve the purpose of improving image bit rate. On this basis,choose Log Luv（ TIFF） coding method for high dynamic statistical correlation between the image information data filtering,high dynamic image adaptive coding. Experimental results show that the proposed method for high dynamic image coding,the image quality is higher,and in the case of low coding efficiency,still can keep high image quality and coding performance is superior to predictive coding method.