基于Android手机的水稻剑叶角测量系统

为了快速、无损地测量水稻剑叶角,设计了基于Android智能手机的便携式水稻剑叶角无损测量系统。采用智能手机后置摄像头获取水稻剑叶基部图像,经过图像预处理、直线检测、K-means聚类和向量方法等处理过程,得到水稻剑叶角。基于Android编程技术对系统软件进行设计,实现了在Android平台下利用JNI和Android NDK调用基于Open CV库的剑叶角提取图像处理算法,实现了新建试验、材料信息输入、摄像头获取剑叶基部图像、计算输出剑叶角及保存数据等界面操作流程。利用该测量系统在田间对4个品种的80株水稻进行剑叶角测量试验,以验证系统性能。试验结果表明,和人工用量角器测量结果相比,该系统测量的平均绝对误差为1.34°,相对误差为2.7%,测量值和真实值相关系数为0.997,能有效测量剑叶角。

Measurement System of Rice Flag Leaf Angle Based on Android Smart Phone

In order to measure the rice flag leaf angle rapidly and nondestructively, a portable system for measuring rice flag leaf angle based on Android smart phone was developed. The rear camera of the smartphone was used for flag leaf images acquisition, and the flag leaf angle was obtained through image preprocessing, lines detection, K-means clustering and vector method. The interfaces and function modules of system software were designed by using the Android programming technology, which realized the extraction algorithm of rice flag leaf angle using JNI and Android NKD to call OpenCV database in the Android platform. It can complete the operational flows of new test establishing, material information inputting, flag leaf images obtaining, angle value outputting as well as interface saving. 80 plants of rices in four varieties were tested to verify the system performance. The test results demonstrated that, comparing with the measurement results of protractors, the average absolute error of this system was 1.34°, the relative error was 2.7%, and the correlation coefficient between the observed values and actual values was 0.997. It was indicated that the proposed system could effectively measure the rice flag leaf angles.