Hybrid Pixel-Based Method for Cardiac Ultrasound Fusion Based on Integration of PCA and DWT

Table 3

Experimental variables of ventricles’ segmentation technique.

Border indicator				Level set			Postprocessing procedures
Gaussian smoothing standard deviation			1.6 or 2^a	Balloon force weight		1	radius of circle, Apex point selection	3
Edge contrast parameter			0.06 or 0.1^a	Regularization weight		0.64	Surface smoothness (Gaussian), standard deviation	0.3
Edge exponent parameter			2	Advection weight		3	—

 ^aBecause of dissimilarities in quality throughout the database, a small subset of echocardiograms was prepared with unique variables intended for smoothing and also border indicator calculation. Typically, this is performed as a result of varying image quality in input echocardiography and less often for fused ones.