There are many ways to perform edge detection. However, the most may be grouped into two categories, gradient and Laplacian. The gradient method detects the edges by looking for the maximum and minimum in the first derivative of the image. The Laplacian method searches for zerocrossings in the second derivative of the image to find edges. This first figure shows the edges of an image detected using the gradient method (Roberts, Prewitt, Sobel) and the Laplacian method (Marrs-Hildreth).

Various Edge Detection Filters |

Vertical and Horizontal Edges |

Vertical Sobel Filter Horizonatal Sobel Filter |

Sobel Filtered Common Edges: Jim Sobel Filtered Common Edges: Roger |

Haar Wavelet Transformed Image Edge Images Generated from the Haar Wavelet Transform |

Haar Filtered Common Edges: Jim Haar Filtered Common Edges: Roger |

Extended Haar Wavelet Transform |

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Click here to go to the automatic morphing page

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