【摘要】 从全息再现的三维图象出发,提出一个推算全息照相信息容量的方法。信息容量为 I=-sum fromj=1 to MlogP_j(K_j),或当P_j(u)=常量=1/K时,I=MlogK,其中M为总的立体象素数,K为每一象素可区分开的灰度阶数。M可从衍射算出,它仅由底片面积决定;K与底片上析出的黑粒密度的随机起伏有关。本文以振幅型“简化胶片”为模型,以等步长的“随机行走”为数学近似,对K进行了推算,并由此指出在一定要求下如何选取胶片的黑粒尺寸及密度。更多还原

【Abstract】 The holographic information capacity of film is analysed in terms of 3-dimensionsl reconstructed image. Information capacity I is defined by two factors M and K, being I=M log K in simple case, where M is the number of image elements and K the number of gray levels. In the case of holography the image elements are 3-diinensional. The number M of 3-d. image elements is deduced from diffraction, and it merely depends upon the film size. But the number K of gray levels depends upon the fluctuation of grain density in the film. The value of K is deduced with a model of "simplified film", using twice the "random walk" method. Then I is given as a function of a (the radius of film) and r (radius of grains in the film). The curve of I vs a and of I vs r are given. It is discussed about how to chose the size and density of the grains under certain conditions.更多还原