分类: 物理学 >> 交叉学科物理及相关领域的科学与技术 提交时间: 2024-03-23
摘要: To predict the fractal decoded image quality more efficiently, an accumulated collage error coefficient (ACEC) based method was proposed in this study. Firstly, the definition of ACEC was introduced to describe the relationship among the upper bound, lower bound, and actual value of theaccumulated collage error of all range blocks. Moreover, the definition and monotonicity of the relative error of ACEC were also defined and discussed. While the relative error of ACEC reaches a relatively small value, the average collage error (ACER) can be estimated approximately, and then the encoding process can be terminated to directly predict the peak signal-to-noise ratio (PSNR) quality of decoded images. Experimental results show that compared with the previous method, the proposed method can predict the decoded image quality more accurately with fewer computations.
分类: 物理学 >> 交叉学科物理及相关领域的科学与技术 提交时间: 2023-09-19
摘要: To accelerate the fractal decoding process, a minimum iterated function system based fast fractal decoding method was proposed in this study. In fractal encoding process, we found that there exists a minimum domain block set (MDBS) which can provide the best-matched domain blocks for all range blocks, and then the domain blocks of MDBS, the range blocks within MDBS, and the associated mapping operations between them constitute the minimum iteration function system (MIFS). In decoding process, MIFS was first recovered in the first iteration. Then, in each of the second to penultimate iterations, only the range blocks within MDBS are reconstructed, and the computations of reconstructing the remaining range blocks can be saved. Finally, all range blocks are reconstructed to obtain the decoded image in the last iteration. Four fractal encoding methods were adopted to assess the performance of the proposed method. Experimental results show that the proposed method can complete the decoding process with fewer computations.