基于MATLAB图像处理的潮位数字化方法及应用

Method and Application of Tide Level Digitizing By MATLAB Image Processing

采用MATLAB图像数值分析和专业位图图像软件相结合的方法,对以图像形式保存的潮位过程进行处理和分析,提取其潮位数据。首先利用位图图像软件对图像进行前期处理,包括图像旋转扭正、增设像素点、色阶处理、点绘关键点及位图化;然后利用MATLAB读取处理后位图图像,通过程序判断关键点所在矩阵位置,通过潮位关键点、横纵坐标关键点对应的矩阵点位位置信息,进行计算分析从而确定潮位值,针对点线型图和连续曲线图提出了不同处理手段。将本方法应用到某潮位站潮位图像的数据提取中,与实测值对比表明,数字化值与实测值吻合度较好,平均误差小于1.0%。本方法可扩展应用于其它类似图件的数值化处理。

MATLAB image processing together with professional photo software is employed to extract tidal level data by analyzing tidal level images. Firstly,tide level image was pre-processed by PHOTOSHOP such as image rotation,pixel increment,levels operation,key-point plotting and bitmapping. Then the image was read by MATLAB and the location of key-points could be obtained by program. The tide level data number was obtained by the relative location of tide level key-points and horizontal and vertical coordinates key-points. In addition,different approaches were specified for point-curve image and continue curve image. This method was applied to the acquirement of tidal level data at a tide-gauge station. Application results indicate that the digitized value was very close to the measured value and the mean error was less than 1. 0% 。This method could be extended to image data acquirement in similar fields.