I’m trying to apply two-point correlation function in Fiji on a stack of images that are actually micro-CT scans of a natural rock. I found Two_Point_Correlation plugin that can calculate this function versus distance in pixel for one single image but not the whole stack. My concern is considering distance in 3D space (like radius of a sphere). I also found a kind of similar function in 3D that can be applied on the whole stack which is Radially Averaged Autocorrelation macro but I’m more interested in two-point correlation function since it is more common in REV study of natural rocks and porous media. I appreciate if anyone knows a proper plugin or macro in ImageJ or Fiji. Thanks.