国产欧美精品一区二区,中文字幕专区在线亚洲,国产精品美女网站在线观看,艾秋果冻传媒2021精品,在线免费一区二区,久久久久久青草大香综合精品,日韩美aaa特级毛片,欧美成人精品午夜免费影视

The measurement of carbonization area in combustion test is a necessary item for the evaluation of flammability of live working shielding clothing. Aiming at the problems of traditional area measurement methods, such as many human error factors, large measurement error and low efficiency, a new sub-pixel area measurement method based on machine vision is proposed. Firstly, the pixel level contour extraction and area measurement are carried out. Then, on the premise of obtaining the pixel level contour, a gradient direction determination method is proposed. The sub-pixel contour is obtained by the arc tangent function fitting method based on the gray value. Finally, the area is calculated by Green's formula. The area measurement experiment was carried out with standard figure block and actual carbonization sample. The results show that the error of sub-pixel area meas-urement method can reach less than2%, which is 4 times higher than that of pixel level method; the standard deviation of sub-pixel level repeated measurement is 5.02 mm2, which is 1/4 of the traditional method; the machine vision measurement method takes 3.6 s for one measurement, which is more than 20 times higher than the traditional method. It provides a simple, accurate and efficient new method for carbonation area measure-ment.