Nicholas Ragosta

CSCI 1430 Project 1

Goal and Method:
To create a hybrid image by combining the low frequencies of one image with the high frequencies of another. Such a composite image is able to fool the eye into seeing the image sampled at low frequencies from afar and the image sampled at high frequencies when close.

    Sampling Frequencies and the Birth a Laplacian Pyramid
  1. A gaussian and laplacian pyramid must be created for each image to isolate frequency ranges.
  2. First, a gaussian blur is applied to the original image. The blurred image is then subracted from the original image to isolate a band of frequencies.
  3. This subtracted image is stored as the first layer of a laplacian pyramid, and the original image is stored as the first layer of the gaussian pyramid.
  4. Next, the blurred image is resized to be half of its lateral and vertical dimensions. This rescaled image is stored as the second layer of the gaussian pyramid.
  5. Steps 2 through 4 are repeated to the current highest level of the gaussian pyramid until gaussian and laplacian pyramids of the desired dimension (N) are created.
  6. Each level of the laplacian pyramid samples a lower frequency range than the previous level.

    Collapsing of the Pyramids: the Ending of the Egyptian Empire
  1. Once a pair of laplacian pyramids and a pair of gaussian pyramids are created the hybrid image can be made.
  2. A cutoff point (C) that determines the number of layers that are taken from each laplacian pyramid must be defined.
  3. The lowest level gaussian of the image that is to have its low frequencies preserved is scaled up to the dimensions of the original image.
  4. This rescaled image is then added layers 2 through C of the laplacian corresponding to the low frequency image.
    Each layer must be scaled to the dimensions of the original image before being added.
  5. Next the higher frequencies of the second image (layers C+1 through N of the second laplacian) are added to complete the hybrid image.

Results:
Below are some of the image pairs I used and the resulting hybrid images.