Dense nonrigid motion tracking from a sequence of velocity fields

Abstract

We have addressed the problem of tracking the nonrigid motion of the heart using a sequence of velocity fields and a sequence of contours.

A region and gradient based active contour model and its application in boundary tracking on anal canal ultrasound images

“…Another kind of method is to extract the motion by pixel intensity analysis of the apparent motion over the region [17,18]. Usually spatio-temporal gradients are estimated as motion information [19][20][21]. The advantages of these models are that they are robust and do not need a specific required initial step, because they make use of the information from the whole region.…”

“…Hence, it has been gaining popularity in clinical examination in the past decade. Anal EUS, which owns a high frequency transducer (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) for detailed resolution, near field focusing, is the one to examine the anorectal tract [1].…”