Patent ID: 8139824
Filing Date: 2012-03-20
Classification: A01D,G01N

Abstract:
1. A method of discriminating between kernel and chaff particles, in crop, using a crop viewing apparatus that includes: a) an image-capturing device that is capable of capturing one or more images, each comprising a plurality of pixels, of crop in the crop viewing apparatus, the image capturing device being operatively connected to an image processing device for processing one or more resulting images; b) one or more lamps for illuminating crop in the crop viewing apparatus, the or each said one lamp being capable of illuminating the crop in a range of illumination levels up to a maximal level equal to or above a reflectivity saturation level; and c) one or more control devices for controlling the level of illumination provided by each said lamp, the method comprising the steps of d) operating at least one said control device to cause illumination of crop in the crop viewing apparatus at one or more level less than the said reflectivity saturation level so as to enhance differences in reflectivity between kernels and chaff in the crop viewing apparatus, and before operating at least one said control device, establishing the or each said one illumination level less than the saturation level, wherein the step of establishing the or each illumination level less than the saturation level includes: determining for a plurality of images of crop or for a plurality of combinations of images of crop a signal-to-noise (SNR) ratio calculated as the absolute value of the difference between the mean reflectivity of chaff and the mean reflectivity of kernels, divided by the sum of the standard deviations of the reflectivities of chaff and kernels; and selecting as the illumination level less than the saturation level the illumination level used in the image or in the combination of images that exhibits the highest SNR value; e) operating the image-capturing device while the crop is so illuminated to capture one or more crop images; and f) operating one or more said image processing devices in order to discriminate in the image between kernel and chaff particles based on their reflectivity characteristics at a said illumination level less than the saturation level.