Foundations
Phase congruency reflects the behaviour of the image in the frequency domain. It has been noted that edgelike features have many of their frequency components in the same phase. The concept is similar to coherence, except that it applies to functions of different wavelength.
For example, the Fourier decomposition of a square wave consists of sine functions, whose frequencies are odd multiples of the fundamental frequency. At the rising edges of the square wave, each sinusoidal component has a rising phase; the phases have maximal congruency at the edges. This corresponds to the human-perceived edges in an image where there are sharp changes between light and dark.
Read more about this topic: Phase Congruency
Famous quotes containing the word foundations:
“If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them.”
—Henry David Thoreau (1817–1862)
“and the oxen near
The worn foundations of their resting-place,
The holy manger where their bed is corn
And holly torn for Christmas. If they die,
As Jesus, in the harness, who will mourn?
Lamb of the shepherds, Child, how still you lie.”
—Robert Lowell (1917–1977)
“As men’s habits of mind differ, so that some more readily embrace one form of faith, some another, for what moves one to pray may move another to scoff, I conclude ... that everyone should be free to choose for himself the foundations of his creed, and that faith should be judged only by its fruits.”
—Baruch (Benedict)