Frequency transforms are new

What are they? If you have dozens of frequencies and apply direct color to frequency conversion, you add a new dimension, frequency, to a defect signal. The defect signal is then viewed in the frequency domain.

If you don't use frequency transforms and analyze looking at just the lissajous signals that result from defects, it is easy to confuse the signal from a through wall hole (or a very deep pit) with a signal from a magnetic inclusion or a roll stop. With frequency transforms, the difference is as clear as black and white.

Inclusion                Hole               Roll Stop