Image processing based package volume detection with Kinect

In this study, an image processing based package volume detection scheme that utilizes Kinect depth sensor was developed in Matlab environment. Background subtraction method was used to obtain the foreground image that contains the package to be measured from the Kinect depth image. Connected components labeling method was used to segment the foreground image. Out of the components determined by connected components labeling, the one that has the maximum pixel area overlapping with the measuring plate was assumed to be the package of interest. Package orientation angle and center point were then determined. Hough transform was applied to the package image to obtain the lines that passes through package edges. The package corners were obtained by finding the four intersection points of the detected lines. Real world coordinates of the package corners were calculated using the Kinect's intrinsic matrix. Package width and length were determined by finding the distance between the corners in the real world coordinate system. Finally, the package height was determined by differencing plate depth and average depth value of points on the package surface. It was observed that the algorithm performed successfully and the measurement error was within 1cm under presence of various disturbance effects.