Real-time Defect Detection in Fruit — Part I: Design Concepts and Development of Prototype Hardware

Three cameras sensing reflectance in the visible region and narrow bands in the near infrared (NIR) region were proposed for simultaneous color evaluation and defect detection. Information from the visible region was intended for use in color grading. A narrow band centered at 780 nm allowed concavity identification with structured illumination, and a second band centered at 750 nm was used for detection of dark spots under diffuse illumination.