Imagine the following images are taken from a population of similar images (in probabilistic terms, the sample space Omega). For instance, image 3 (Mars surface) is one of many images taken during the recent Pathfinder mission. Each image is viewed as a realization of a random process. The question is:


Are these random processes stationary, ergodic, and/or isotropic?


Image 1: binary image (2 equiprobable levels 0 and 255), i.i.d pixels.



Image 2: binary image (2 equiprobable levels 0 and A), i.i.d pixels. A is a binary random variable with 2 equiprobable values, 127 and 255.



Image 3: section of Mars surface



Image 4: fingerprint



Image 5: MRI brain image



Image 6: soccer crowd



Image 7: building



Image 8: a happy fellow



Image 9: diffuse radar target