【作者】 刘丹；

【导师】 孟丽艳；

【作者基本信息】 大连海事大学 ， 信息与通信工程， 2012， 硕士

【摘要】 水尺计重(Draft survey)是测定船舶装、卸货物前后的平均吃水数据所对应的排水量差值,扣除船舶中的其它载荷重量计算船舶载货量的方法。煤炭、矿石、化肥等大宗散货物品通常用此方法进行计量。本课题主要研究了利用图像处理技术确定人眼不易识别的吃水线位置。针对水尺图像采集环境的特点,本课题采用了基于爬壁机器人为载体的图像采集装置；针对水尺图像的特点,本课题采用了基于形态学、投影和图像分割的算法对水尺图像进行的检测处理。基于提高后续检测精度的目的,系统采用高分辨率的图像采集装置进行水尺图像的采集。为了降低后续处理的数据量,首先对图像进行二值化分割,获得高亮度的字符区域,并以此为基础在高度方向对图像进行投影统计,提取出离水线最近的“M”字符区域并进行倾斜校正,然后对”M”字符区域进行分割和对“M”字符前面的数字进行识别。对“M”下面的小字符进行分割和识别,并确定离水面最近的可识别字符。为了防止因船舶形状对字符大小的影响,可以根据数字的识别效果以“M”字符所占的像素个数或者离水线最近的可识别数字所占的像素个数为计量标准。再次以可识别数字的下边缘为界对彩色图像进行剪裁,然后对彩色图像进行分割以及提取最长边界并拟合水面位置,为了防止检测结果受海水波浪的影响,对检测结果进行均值运算确定水面所在的位置。本文针对船舶水尺字符的特点,对船舶水尺图像进行了充分的预处理,包括对字符的分割、倾斜校正和图像剪裁,获得了较好的检测和识别效果；通过彩色图像分割确定吃水线位置,按照水尺计重的规则,利用“M”前面的字符识别结果、计量标准和水面位置计算水尺数据。通过对实地采集的图像进行处理检测,表明此方法是有效的,实现船舶的自动水尺计量系统是可行的。更多还原

【Abstract】 Draft survey is a method of through the determination of ship’s average draft corresponding to the difference in value of displacement before and after unloading,deduct other load weight and calculate the amount of dead weight.The method is usually as the measurement of the major bulks,such as coal,ore,fertilizer and so on.The paper mainly does the research on how to get the position of the waterline using image processing technology,which is not easy for human eye. According to the characteristics of draft image acquisition,the paper adopts climbing robot as the carrier of image acquisition device.The paper adopts algorithm processing draft image based on morphological,projection and image segmentation.In order to improve the measurement precision,using the high resolution image acquisition device.For reducing the volume of the following-up processing,the paper firstly take the binary segmentation to get the characters area of high brightness,and projection statistics in the height of image direction,then extract the recent "M"character area from waterline and tilt correction,next segment the "M"regional and identify the digital before the "M"Segmentation and recognition the small character below the "M"and determined the character which is nearest from the waterline.In order to prevent the shape of ship influence the size of characters,we could use the number of pixels for measure standers,the "M"characters or the digital which is nearest from the waterline and recognition.Clipping the color image with a boundary that is the bottom edge of identified digital.And then segmenting the color image and extracting the longest boundary and fitting the waterline position.According to the characteristics of the draft character,we carried out a full image pretreatment process, including the character segmentation,tilt correction and image clipping,whichhas good processing and recognition effect.Then using the color image segmentation determine the position of the waterline. Finally, calculating draft data according to the recognition results of the digital before the "M" area, measurement standard and the position of waterline using the draft survey regulations.After the multiple experiments on many images, it is proved that this method is effective and realizing the ship’s automatic draft survey system is feasible.更多还原