Fall 2008

Greg Eden

To speed up the process of aligning large images, I implemented the image pyramid search procedure, in which I recursively halved the dimensions of a given image using bicubic scaling until the image width was below a certain size. This allowed me to to search a much narrower range of displacements for each image size, since at each level of the pyramid I was able to recursively use the estimated alignment from the half sized image as a central offset for the displacement window. The images you see in the next sections have been aligned using this coarse-to-fine image pyramid method. Also, I have added tweaks involving edge detection and cropping, which were used as well for generating these images. I'll explain these additional features in detail further down the page.

Green displacement: x = 2 and y = 6 Red displacement: x = 1 and y = 10 |
Green displacement: x = 2 and y = 4 Red displacement: x = 2 and y = 9 |

Green displacement: x = 3 and y = 7 Red displacement: x = 4 and y = 14 |
Green displacement: x = 0 and y = 5 Red displacement: x = -2 and y = 11 |

Green displacement: x = 1 and y = -3 Red displacement: x = 1 and y = -4 |
Green displacement: x = 1 and y = 3 Red displacement: x = 1 and y = 12 |

Green displacement: x = 3 and y = 5 Red displacement: x = 4 and y = 11 |
Green displacement: x = 0 and y = 5 Red displacement: x = 0 and y = 11 |

Green displacement: x = -1 and y = 6 Red displacement: x = -3 and y = 12 |
Green displacement: x = 0 and y = 8 Red displacement: x = 0 and y = 13 |

Green displacement: x = 2 and y = 6 Red displacement: x = 4 and y = 13 |
Green displacement: x = 0 and y = 4 Red displacement: x = 0 and y = 10 |

Green displacement: x = 2 and y = 2 Red displacement: x = 3 and y = 6 |
Green displacement: x = 3 and y = 0 Red displacement: x = 3 and y = 2 |

Green displacement: x = 3 and y = 6 Red displacement: x = 3 and y = 13 |
Green displacement: x = 4 and y = 11 Red displacement: x = 5 and y = 23 |

Green displacement: x = 2 and y = 4 Red displacement: x = 1 and y = 10 |
Green displacement: x = 0 and y = 4 Red displacement: x = 0 and y = 11 |

Without Edge Detection |
With Edge Detection |

Without Cropping |
With Cropping |