IMAGE-PROCESSING SOLUTION TO COTTON COLOR MEASUREMENT PROBLEMS: PART I. INSTRUMENT DESIGN AND CONSTRUCTION

Trash particles enmeshed in bulk cotton fiber samples interfere with conventional cotton color measurement accuracy. A new instrument was designed and constructed for reducing trash effects on cotton color measurement, while maintaining the traditional system of cotton color measurement. The instrument’s illumination system included four quartz-tungsten-halogen lamps in aluminum elliptical reflectors. The instrument’s sensor was a panchromatic video camera that acquired images through optical color filters on a rotating wheel. The sensitivities of the various measurements were rigorously considered to maximize the dynamic range over which each measurement was made. The system’s camera was connected to a computer through a frame grabber. Software was written to control the filter wheel, image acquisition, color/trash computations, and data recording. Image processing was employed to differentiate trash particles from cotton in the images. Color was calculated from the image portion judged by image analysis to be cotton. The system was tested on a large number of cotton samples and performed as designed and without any software or hardware failures.