class_docstr: Apply LightSource filter
class_docstr_tok: ["Apply","LightSource","filter"]
code: def process_image(self, padded_src, dpi):
      t1 = self.gauss_filter.process_image(padded_src, dpi)
      elevation = t1[:, :, 3]
      rgb = padded_src[:, :, :3]
      alpha = padded_src[:, :, 3:]
      rgb2 = self.light_source.shade_rgb(
          rgb, elevation, fraction=self.fraction, blend_mode="overlay"
      )
      return np.concatenate([rgb2, alpha], -1)
  
imports: import matplotlib.pyplot
  import numpy
  from matplotlib.artist import Artist
  import matplotlib.cm
  from matplotlib.colors import LightSource
  import matplotlib.transforms
label_desc: Use image node_id 3 for calling the LightFilter obj's underlying member method code with example usage: obj.process_image(padded_src, dpi) and returns: np