Blob detection supports for non-integer sigmas

Hello,
I noticed that in all the blob detectors peaks are found like this:

    local_maxima = peak_local_max(image_cube, threshold_abs=threshold,
                                  footprint=np.ones((3, 3, 3)),
                                  threshold_rel=0.0,
                                  exclude_border=False)

    # Convert the last index to its corresponding scale value
    local_maxima[:, 2] = sigma_list[local_maxima[:, 2]]
    
My sigma list contains floats in it that a re converted to int64 when the sigma list is copied back into local_maxima.  I had to modify the code so local_maxima[:,2] still contained a list of integers but the results are now stored as a float32.

I've made a quick change to fix this issue:

    # Convert array to float32
    lm = local_maxima.astype('float32')
    lm[:,2] = sigma_list[local_maxima[:,2]]
    local_maxima = lm