由于视频图像的信息量巨大,只有通过压缩才能存储和传输,而传输过程中发生的误码又往往导致压缩后的图像数据或同步信息的丢失,为此提出了一种基于帧间匹配均值与方差的时域错误隐藏算法,该算法首先以与错误块上、下、左、右相邻的若干行或列像素进行帧间匹配,然后根据匹配结果的均值和方差判别错误块内图像的运动状况,最后针对不同的运动状况选择合适的隐藏方法对错误块进行隐藏处理。大量的模拟实验结果表明,利用该算法隐藏的图像在视觉效果和峰值信噪比(PSNR)两方面均优于同类算法。
Because of vast amounts of information, compression of video signals before saving and transmission is necessary. Communication channels are not error free and, consequently, the encoded bit streams are vulnerable to transmission errors-usually causing loss of data and/or loss of synchronization. Therefore, a temporal error concealment algorithm based on interframe matching mean and variance is presented. The algorithm searches the best match block by matching the pixels adjacent to the error block, and then calculates the matching mean and variance of difference between different neighborhoods. From the result, the motion characteristics are estimated and different candidate blocks are chosen for different motion characteristics. Experimental results show that both the visual quality and PSNR of the image processed using the proposed error concealment method are better than other temporal algorithms.