Width and pitch within a plane parallel to the calibration plate is measured.
Following video shows measurements of rod diameter and pitch.

Even with one view, object height can be calculated.  In the video, top and bottom profiles are extracted as circle and then height is calculated from the two circles.

Measurements of hole diameter and distance between hole centers.  With using 12M pixel camera, results were as good as CMM (difference was only 25μ).

Calculation of futsal-court area.

Example of Ortho-rectification.

Even very faint crack can be traced and extracted as DXF.  Measure is calculated in real size.

With the use of laser rangefinder, measurements of far distance or large structures are possible.

Take two pictures at different angle to calculate 3D position.

Hole position calculation from two angled photographs.

3D position calculation from image(s) is also applicable to robot teaching.

Like Single View, far distance objects and large structures are measurable with the use of laser rangefinder.  3D positions and dimensions are calculated.