DUAL-CAMERA NIR/MIR IMAGING FOR STEM-END/CALYX IDENTIFICATION IN APPLE DEFECT SORTING

摘要

One of the persistent problems involved in the technology of automated machine vision apple defect sorting lies in the discrimination between true defects and the stem-end/calyx of fruit. To solve this problem, a novel method was developed which incorporates a near-infrared (NIR) camera and a mid-infrared (MIR) camera for simultaneous imaging of the fruit being inspected. The NIR camera is sensitive to both the stem-end/calyx and true defects; whereas the MIR camera is only sensitive to the stem-end and calyx. True defects can be quickly and reliably extracted by logical comparison between the processed NIR and MIR images. A 98.86% recognition rate for stem-ends and a 99.34% recognition rate for calyxes were achieved using a dual-camera NIR/MIR machine vision defect sorting system.