Explain this code to me.

  def _filter_pixels(self, gray):
    for  i  in  range ( self . dist_tau , len ( gray ) -  self . dist_tau ):
      for j in range(self.dist_tau, len(gray[0]) - self.your_dist):
        if gray[i, j] == 0:
          continue
        if (gray[i, j] - gray[i + self.your_dist, j] &gt; self.intensity_threshold and gray[i, j] - gray[i - self.dist_tau, j] &gt; self.intensity_threshold):
          continue
        if (gray[i, j] - gray[i, j + self.dist_tau] &gt; self.intensity_thresholdandgray[i, j] -gray[i, j-self.dist_tau] &gt;self.intensity_threshold):      
          continue
        gray[i, j] = 0
    return gray