noise

• Makes it difficult to find edge for Edge Detection
  • Larger the noise, larger the gradient

fix

• smooth the image by making pixels look more like their neighbors, then take the gradient of that
• smooths but blurs edges
• Examples
  • mean smoothing
  • gaussian smoothing
  • size of filter is a hyperparameter
    • blurrier when we increase size, i.e. from 3x3 to 7x7