Monocular 2 ½ D – Depth from Focus & Sheet of Light
Several images of the object are taken with different distances.
The change in focus is used to calculate distance information.
The 3D shape of an object is determined by measuring the profile
of the object along a projected line of light.
Introduction of the technology
There are various so-called active technologies for the extraction of height information with one camera. The resulting 3D information is very similar to binocular stereo. The most often used methods are:- Depth from focus (DFF) extracts distance information by calculating the focus of all pixels of the image. A small depth of focus is used to calculate the distance of the object’s surface to the camera.
- Sheet of light means measuring an elevation profile of an object by reconstructing the projected line of light on this object.
Particularly suitable for ...
3D reconstruction – in case of DFF especially suitable for small objects, in case of sheet of light for objects without texture. Typical application examples include quality inspection of 3D objects as well as position recognition of 3D objects.Supported by HALCON
For dense height maps, HALCON offers various methods that can be used to process 2 ½ D images, e.g., to determine object edges or angles between 3D planes. In the case of sheet of light, also highly accurate line- or point-oriented 3D measurements can be applied.Application example
- Depth from focus with HALCON
- Sheet of light with HALCON
PCB trace inspection with DFF using HALCON.
Measuring the object with sheet of light using HALCON.
3D Vision Technologies
- 3D Calibration
- 3D Matching
- Perspective Matching, Circle Pose & Rectangle Pose
- Binocular Stereo
- Monocular 2 ½ D – Depth from Focus & Sheet of Light
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vision brochure
