Measuring crops in 3D: using geometry for plant phenotyping

Table 1 Technical overview of 3D measuring methods

Name	Abbr.	Resolution	Active illumination	Direct point cloud access	Output values	Price	Literature
Laser triangulation	LT	< mm	Yes	Yes	XYZ (I)	€€€	[10, 26]
Structured light approaches	SL	< mm	Yes	No	XYZI (RGB)	€€	[18, 27]
Structure from motion	SfM	mm	No	No	XYZRGB	€	[17, 28]
Time of flight	ToF	mm	Yes	Yes	XYZ (I)	€€	[29, 30]
Light field measuring	LF	mm	No	No	XYZRGB	€€€	[31, 32]
Terrestrial laserscanning	TLS	cm	Yes	Yes	XYZ (I/RGB)	€€€	[33, 34]

The differences in illumination, direct or needed postprocessing, pricing and resulting values is given. Pricing is encoded by € < 1000 Euro, €€ < 10,000 Euro and €€€ > 10,000 Euro. The output values show XYZ coordinates and a possible enrichment with I for intensity/reflectance or RGB for a Red-Green-Blue image combination

ISSN: 1746-4811