Gazo shori ni yoru okugai denryoku setsubi no kanshi. Teishodoji no densen tsuiseki arugorizumu no kaihatsu. (Development of image processing technique for outdoor monitoring image. Tracking method of swinging power transmission line under low brightness)

摘要

An algorithm for tracking power transmission line has been developed by means of image processing technique which can track the moving line even under low brightness like early morning. Its performance was verified using test images and recorded images of power lines. A non-linear brightness conversion technique is proposed, by which the image of power line can be made clear by enhancing the contrast of the low brightness part for images under low brightness like early morning and the high brightness part for images under excess brightness due to counterlight. To track moving line body, modeling of chaining of rectangular regions and a tracking method are proposed. Through the simulation, the tracking limit was determined by adding noise to the test image of moving line body. In the case of 256 gradation, when a brightness difference of 30 gradation was secured between the power line and background, the power line could be stably tracked even at the S/N ratio of 10 dB. For the recorded images of power lines in strong wind or snowy weather, the power lines were stably tracked even when they were swinging with moving shading. 8 refs., 23 figs., 3 tabs.