Remote Measurement Method for Three-dimensional Shapes, Especially Volumes, of Attached Fruits Using Stereo Photogrammetry

Abstract

The remote measurement of the three-dimensional shapes and volumes of attached fruits was examined using software for stereo photogrammetry. It read the three-dimensional coordinates of many surface points on viewing fruit from two sides, the front and back, those of fruit boundary lines, and, if necessary, those of the cavity surfaces and ridge lines surrounding the fruit cavities. The volume of each square pole, composed of four adjacent surface points, was calculated by a computer program within area on each fruit side, and totaled as the fruit volume. If necessary, a similar volume was calculated within the cavity area, and totaled as the cavity volume. The latter was used to deduce the net fruit volume from the former. The relations between the measured volumes and remotely measured volumes of detached fruits were satisfactory. A field photography device was devised, which consisted of a tripod, a ground control-point set and a board on which the camera slid from left to right. Remote measurements of the volume of attached fruits were carried out successfully using this device. Other fruit shapes excluding the volume could be measured easily using the software.