Image Processing Reference
Now, the problem converges to the solution of . The solution will be the estimation of
optical flow. As there are two unknowns in the equation, it cannot be solved; additional con-
straints and approaches are needed for solution. This problem is known as aperture problem .
Many algorithms according to different approaches have been proposed for optical flow es-
according to the theoretical approach while interpreting optical flow. These are differential tech-
niques, region-based matching, energy-based methods and phase-based techniques .
4.2.1 Differential Techniques
Differential techniques utilize a kind of velocity estimation from spatial and temporal deriv-
used for solving the problem generally represented by this equation. Horn-Shunck method