Despeckle Filtering for Multiscale Amplitude-Modulation Frequency-Modulation (AM-FM) Texture Analysis of Ultrasound Images of the Intima-Media Complex

Table 1

Despeckle filtering demonstrating its advantages applied to a synthetic AM-FM example (see text for details). Note significant noise estimation improvements for the narrow strips.

Frequency component	x-component of low instantaneous frequency; (LIFx)			y-component of low instantaneous frequency; (LIFy)
	Backgrounds	Strips	Combined	Backgrounds	Strips	Combined
Noise-free, low-scale AM-FM (upper bound of what can be achieved)	3.9𝐸−06	7.6𝐸−02	2.7𝐸−03	2.9𝐸−02	5.5𝐸−01	4.8𝐸−02
Speckled image, low-scale AM-FM estimation (no despeckling)	5.5𝐸−04	1.2𝐸−01	4.9𝐸−03	3.3𝐸−02	4.9𝐸−01	4.9𝐸−02
Despeckling using DsFlsmv	7.3𝐸−04	5.1𝐸−02	2.5𝐸−03	6.8𝐸−02	2.6𝐸−01	7.5𝐸−02
Despeckling using DsFhybridmedian	1.6𝐸−03	4.6𝐸−02	3.1𝐸−03	6.2𝐸−02	4.1𝐸−01	7.4𝐸−02
Despeckling using DsFKuhawara	6.9𝐸−03	7.3𝐸−02	9.3𝐸−03	6.4𝐸−02	4.8𝐸−01	7.9𝐸−02