Image analysis to calibrate French Bean (Phaseolus vulgaris L.) pods

Abstract

Date du colloque&nbsp;: 08/2010International audienceIn order to control the characteristics of a variety, bean breeders have to calibrate pods. This calibration is manually realized, workers have to pass pods through a sieve with holes of different diameter in it, each hole corresponding to a caliber. Pods are weighted, and a repartition in the different calibers in weight is given. This calibration is very tedious, moreover, there is an inter and intra-variability between workers, and the number of characteristics measured is limited.&nbsp;A new automatic method based on image analysis has been performed, it permits in a limited time, to extract and calculate different pods’ characteristics such as the length, the diameter and the curvature, it offers the possibility to conserve images that is helpful for the traceability of products, and it requires less labor than the actual system (manual ones). Moreover, a relation between surface of pods and weight has been found, allowing the program to give directly the repartition in the different caliber in weight.&nbsp;An acquisition chain as been installed, composed of a mono CCD sensor camera, manually configured, with a backlight fluorescent system of 5000°K, a tripod and a computer. Images are taken in RAW format, which contrarily to the JPEG is not compressed and avoid edges effects.&nbsp;Images are pre-processed in order to eliminate the noise and converted in binary images. Then algorithms principally based on morphological mathematics, are applied in order to calculate the different characteristics.&nbsp;The validation of the program has been performed on more than 150 batches of different varieties of French and butter bean pods along 2008 and 2009.&nbsp;In this presentation, the image analysis system is described, results obtained with the image analysis system are explained and compared to the manual system.</p