影像的分形研究是图象分析中的一个新课题.该文通过对分形原理、传统的分形计算方法的研究,结合热图象特征给出了3种不同的分维计算方法—灰度曲面分形计算,剖面曲线分形计算,象元点分形计算.实践表明灰度曲面分形计算可以揭示热图象整体的分形特征;剖面曲线分形计算则可对比研究典型地域的热辐射特征;象元点分形计算可以给出热辐射变化梯度的定量描述.在讨论了有关分形性质后,给出了上述方法在上海市热图象场分形量测中的良好应用,并分析了分形计算结果的物理含义.

Image fractal dimension is a useful measure which can be used to characterize features of images. In this paper, three new methods—gray scale surface fractal, curse fractal, pixel fractal to estimate the fractal dimension of thermal image are proposed. The practices indicate that gray scale surface fractal can open out the unitary fractal character of thermal image, curse fractal can contrast and research the thermal radiation character of typical area and pixel fractal can give a quantitative description of variety grades of thermal radiation. After the researching of general fractal theory, the related characters of those methods are discussed. As an example, Shanghai City thermal image is given and the signification of experimental result is analyzed lastly.