What is a stereo measurement? 

In this article:

• Stereo measurement explained: How traditional stereo uses dual images to calculate 3D coordinates for precise dimensional measurements during video borescope inspections.
• Limits vs. advances: Why classic stereo lacks a full 3D point cloud—and how Live 3D Stereo improves confidence by combining 2D views with real-time 3D data. 
• Measurement context: How stereo measurement compares to simpler 2D comparison methods and when each approach is most suitable in inspection workflows. 

What is a stereo measurement?

Traditional stereo measurement, which, like 3D Stereo, utilizes a prism to obtain left and right stereo images from slightly different perspectives. The matching of surface points in the left and right images at the cursor locations allows 3D coordinates and measurement results to be computed. This technology, available for more than two decades, is useful on systems with limited computing power, but does not provide a 3D point cloud and therefore limits the inspector’s ability to assess measurement quality.

Live 3D Stereo

To optimize the measurement process and maximize the quality of results, engage Live 3D Stereo to activate the split-screen view: 2D live image on left and live 3D point cloud on the right. Ensuring you have a quality point cloud containing the area of interest and showing little or low noise levels provides more confident measurement assignments on the first attempt.

Comparison Measurement

A more traditional 2D measurement technology that uses a physical reference target placed by the manufacturer or inspector at the same tip to target distance as the indication.