Calculation of Optical Flow

(Horn-Schunck Algorithm)

COMPSCI 775ST Assignment 3
From: 21/08/2002
Due: 18/09/2002 2:00pm

• Aim

• Resource

• Goal

• Details

• Questions to be answered

• Example of results

• Understand Optical Flow
• Understand Horn-Schunck Algorithm

For your input images, you may select two pairs or more from the following images.

• mysine1.bmp and mysine2.bmp
• rubic1.bmp and rubic2.bmp
• square1.bmp and square2.bmp
• taxi1.bmp and taxi2.bmp
• trees1.bmp and trees2.bmp

You need to use the total error functional (on page 80 of handout) and Horn-Schunck algorithm to calculate the optical flow for pair(s) of sequential images.

• Choose pair(s) of sequential images.
• Describe the procedures involved in the calculation of optical flow.
• Perform Optical Flow Calculation using Horn-Schunck Algorithm.
• Represent the optical field (some examples are given below).
• Verify your results and discuss the errors.
• Compare and discuss results obtained by different numbers of iterations.
• Compare and discuss results obtained by different values of lambda.
• Compare and discuss results obtained by different initial values.
• Compare and discuss results obtained by different approximation rules of Ex, Ey and Et.

• What assumptions have you made?
• What is the Horn-Schunck constraint?
• What do Fs and Fh represent?
• What is the aperture problem?

Here are some example results to provide a rough idea of what to expect in the result.  Please note that the other representations of results are also possible.