Simple filter for noise for CSPAD data. Good for finding the center.

find_edges.py

import numpy as np
from scipy.ndimage import filters    

def find_edges(image, threshold=0.01, minf_size=3, medf_size=10):
    """
    Applies an edge filter followed by a noise reduction filter. Very good
    at locating powder rings and filtering everything else out.
    
    Parameters
    ----------
    image : ndarray
        An image to find the edges of
            
    Returns
    -------
    binary_image : ndarray, np.bool
        A binary image, with "1" where there are powder rings/strong edges
    """
    
    image = np.abs(filters.sobel(image, 0)) + np.abs(filters.sobel(image, 1))
    image -= image.min()
    
    assert image.min() == 0
    assert image.max() > 0
    
    # print 'threshold value: %d' % (image.max() * self.threshold)
    image = (image > (image.max() * threshold)).astype(np.bool)
    
    image = filters.minimum_filter(image, size=minf_size)
    image = filters.median_filter(image, size=medf_size)
        
    return image.astype(np.bool)