The barrier coverage problem is very important and challenging in Wireless Visual Sensor Networks (WVSNs). However, previous research of WVSNs did not consider breadth of coverage and thus could not ensure high Quality of Monitor (QoM). Two segments of an image are captured at time point t=0 and t=1 respectively. Because both of these two image segments have a small width, it is not easy to identify the intruder. If there is a requirement of breadth for each barrier, the authors may be able to identify the intruder more easily and quickly.