CAJ | 학술논문

针对目前指针式仪表读数识别算法易受光照影响，并且对较粗指针的仪表识别率不高的问题，本文提出一种基于指针区域的仪表读数识别算法。本文方法可分为两个阶段：第一阶段设计高斯型同态高通滤波器，增强仪表图像对光照变化的适应性；并通过减影法、二值化、中值滤波、图像形态学处理等预处理方法减缓噪声、仪表非指针区域的干扰，突出仪表图像指针区域。第二阶段本文通过计算指针图像旋转不同角度后在纵轴投影，计算指针旋转至平行于横轴时旋转的角度；然后结合指针平行于横轴时在横轴上的投影得到指针夹角，最后通过指针夹角与仪表刻度对应关系识别仪表读数。本文算法简单稳定，得到的仪表读数与人工读数误差较小，同时能够较好适应光照变化。
침대목전지침식의표독수식별산법역수광조영향，병차대교조지침적의표식별솔불고적문제，본문제출일충기우지침구역적의표독수식별산법。본문방법가분위량개계단：제일계단설계고사형동태고통려파기，증강의표도상대광조변화적괄응성；병통과감영법、이치화、중치려파、도상형태학처리등예처리방법감완조성、의표비지침구역적간우，돌출의표도상지침구역。제이계단본문통과계산지침도상선전불동각도후재종축투영，계산지침선전지평행우횡축시선전적각도；연후결합지침평행우횡축시재횡축상적투영득도지침협각，최후통과지침협각여의표각도대응관계식별의표독수。본문산법간단은정，득도적의표독수여인공독수오차교소，동시능구교호괄응광조변화。
Reading recognition algorithms for pointer type meter are vulnerable to illumination, and recognition rate for thicker pointer is not high. In this paper, we propose a reading recognition method based on pointer region. In detail, this approach can be divided into two phases: in the first phase, the proposed method designs Gaussian homomorphic high-pass filter to enhance the adaptability to the illumination change for instrument image, and utilizes image preprocessing methods (including image subtraction, binarization, median filter, image morphology processing et al.) to reduce noise interference, suppress of background region, outstand pointer region. In the second phase, the presented method firstly rotates the meter image, and computes projection of the rotated image on the vertical axis in each rotation angle, then calculates the rotated angle which rotate the pointer of meter image to parallel to the horizontal axis. Whereafter, the deflection angle of pointer can be derived for combining the projection of rotated image on the horizontal axis which the pointer of rotated image parallels to the horizontal axis. Finally, reading recognition is identified by the relation between the pointer angle and the corresponding instruments scale. This approach is simple and stable, the error between the reading of the proposed approach and artificial reading is small, and it can better adapt to illumination changes.