Computer Vision Approach for Low Cost, High Precision Measurement of Grapevine Trunk Diameter in Outdoor Conditions

TL;DR

This paper introduces a low-cost, high-precision computer vision method for measuring grapevine trunk diameter, aiming to replace manual tools with an autonomous system suitable for widespread agricultural use.

Contribution

The work presents a semi-autonomous, cost-effective measurement technique that achieves precision comparable to manual calipers, with potential for full automation in vineyard management.

Findings

Method achieves accuracy similar to manual calipers.

Cost reduction enables large-scale adoption.

Potential for full automation in vineyard measurements.

Abstract

Trunk diameter is a variable of agricultural interest, used mainly in the prediction of fruit trees production. It is correlated with leaf area and biomass of trees, and consequently gives a good estimate of the potential production of the plants. This work presents a low cost, high precision method for the measurement of trunk diameter of grapevines based on Computer Vision techniques. Several methods based on Computer Vision and other techniques are introduced in the literature. These methods present different advantages for crop management: they are amenable to be operated by unknowledgeable personnel, with lower operational costs; they result in lower stress levels to knowledgeable personnel, avoiding the deterioration of the measurement quality over time; and they make the measurement process amenable to be embedded in larger autonomous systems, allowing more measurements to be taken with equivalent costs. To date, all existing autonomous methods are either of low precision, or have a prohibitive cost for massive agricultural adoption, leaving the manual Vernier caliper or tape measure as the only choice in most situations. In this work we present a semi-autonomous measurement method that is susceptible to be fully automated, cost effective for mass adoption, and its precision is competitive (with slight improvements) over the caliper manual method.