The same technological trends that have improved the capabilities and reduced the price of video surveillance systems have reduced the drudgery and expense of 24/7 monitoring of the images these systems capture.

Software to streamline recording of key events while simultaneously alerting you to unusual activity is widely available and often is included with more sophisticated surveillance systems. Still other software is available to automatically scan hours of recordings to identify activity that may merit your attention after the fact.

Here’s a brief look at three software products to build or supplement automated monitoring software that may be included with a turn-key surveillance system.

Blue Iris video management software (blueirissoftware.com) turns your personal computer into a video recording system that uses motion or audio sensing to trigger recording. It can send alerts via email, instant message, voice phone call or loudspeaker. A version for multiple cameras retails for $49.95.

XProtect Go, from Milestone Systems (milestonesys.com) offers similar support for up to eight cameras for free. Versions supporting more cameras, and with additional features, are available for a fee.

Vitamin D software (vitamindinc.com), which is free for a single camera, provides a people-detection option that reduces false alerts triggered by swaying branches, pets and light changes from clouds. Plus it saves time by compiling a daily highlight “reel” of significant events. Versions for multiple cameras are available for a fee.