It would be wasteful of processing time, but quick to implement: up-sample interpolate your Z-axis so that you have a cubic voxel size. I would probably also down-sample interpolate the XY-axes by a factor of 2 or 4 to make the data volume more manageable. 512 x 512 x 512 is a pretty easily manageable size for tomography.

On Mon, May 13, 2019 at 10:35 AM Francesco Alemanno <francescoalemanno710@gmail.com> wrote:
Hello everyone, recently (and for the first time) i had to deal with image processing,
my problem is detecting sferical blobs in a 3D grayscale image shaped like this (20,1000,1000).
So i looked inside scikit, and i found the function blob_dog&log&doh (the three main algorithms),

the procedure is working perfectly for the X and Y coordinates (x,y in [0,1000]x[0,1000])
but failing miserably at identifying the correct Z coord (Z in [0,20]).

I think this has to do with:

the blobs occupy rougly 30x30 pixels in X,Y, but only 3/4 pixels in Z (since my 3D images have to be taken with a lower resolution in Z).
Moreover the algorithms apparently use isotropic gaussian filtering so the variance is the same in all directions (at a given sigma scale) according to the algorithm (Unfortunately not according to my data).

Is there any reasonable/sane way to fix for this? What do you guys suggest?
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