A researcher from the Valencian Institute of Agrarian Research (IVIA; Moncada, Spain) has developed a system that uses a medical magnetic resonance imaging (MRI) scanner to detect seeds in mandarins.
By correctly choosing a suitable repetition rate and echo time of pulses from the MRI scanner, Dr. José Blasco was able to obtain a sequence of images with enough contrast so that he could then use an image thresholding technique to separate the seeds from the background. From the resulting image, the contour of each object could be analyzed and its area calculated.
In doing so, the MRI system was capable of detecting all of the seeds in the mandarins with no false detections. Hence Blasco believes that the technique could be used to separate seeded and seedless mandarins noninvasively and nondestructively.
The next step is to reduce the cost of the equipment and the time needed to acquire and process the images. To convert the IVIA laboratory demonstration into a practical, cost-effective system, Blasco says that MRI technology needs to be developed that is optimized for in-line inspection of fruits and vegetables in a factory environment.
More information is available at http://spie.org/x84974.xml?ArticleID=x84974.
-- By Dave Wilson, Senior Editor, Vision Systems Design
