Measurement

R2026b

Measure distances and geometric features for metrology and dimensional inspection
Since R2026b

Transform image data from pixel coordinates into calibrated world units and perform precise geometric measurements. The Visual Inspection Toolbox™ supports these measurement processes:

World-plane mapping — Map images and individual points to a planar measurement surface using camera intrinsics and extrinsics, correcting lens and perspective distortion.
Caliper tools — Measure distances along straight-line profiles, programmatically or interactively.
Geometric fitting — Fit angles, circles, and perpendicular distances to edge features for dimensional measurements, with automatic edge snapping for repeatable placement.

These capabilities support dimensional inspection, part verification, and metrology applications where pass or fail decisions depend on calibrated world unit measurements.

Functions

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World Unit Measurement with Calibrated Cameras

`imageToWorldPlane`	Rectify and align image with reference plane in world coordinate system
`imageToWorldPlaneMapping`	Compute displacement field to map image plane with reference plane in world coordinate system
`imagePointsToWorldPlane`	Project image points onto reference plane in world coordinate system

Measure Distance Using Straight-Line Caliper

`caliper`	Measure distance in image data using caliper tool
`uicaliper`	Interactively measure distances in images using caliper tool

Measure Distances Using Geometric Tools

`fitangle`	Measure angle in image using angle tool
`fitcircle`	Measure circle in image using circle tool
`uitsquare`	Interactively measure distance perpendicular to edge using point-to-line measurement tool
`uifitangle`	Interactively measure angle in image using angle tool
`uifitcircle`	Interactively measure circles in image using circle tool
`snap`	Snap measurement tool line or points to edge in image

Featured Examples

Perform Metrology Edge Measurements and Alignment

Perform distance measurements of fill lines in soda bottles using a caliper tool, and develop a classification model for normal and anomalous fill line images.

Open Live Script

New

Create an App to Measure Images Using Edge‑Snapping Metrology

Build an app to interactively measure images with edge snapping measurement functions using App Designer.

Open Live Script

New

Automate Calibrated Image Measurement Using Shape Matching

Measure objects at subpixel accuracy in calibrated camera images using shape-based matching and caliper tools.

Open Live Script

Inspect Bottle Fill Level During Live Image Acquisition

Detect an anomaly in a bottle fill level during live image acquisition using the caliper tool.

(Image Acquisition Toolbox)