java opencv 4.0.1安装配置no opencv_java401 in java.library.path
如果没有把dll扔到jdk会报错
Exception in thread "AWT-EventQueue-0" java.lang.UnsatisfiedLinkError: no opencv_java401 in java.library.path at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1867) at java.lang.Runtime.loadLibrary0(Runtime.java:870) at java.lang.System.loadLibrary(System.java:1122) at com.hs.jframe.Jframe.jButton5ActionPerformed(Jframe.java:225) at com.hs.jframe.Jframe.access$000(Jframe.java:25) at com.hs.jframe.Jframe$1.actionPerformed(Jframe.java:107) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402) at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252) at java.awt.Component.processMouseEvent(Component.java:6539) at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) at java.awt.Component.processEvent(Component.java:6304) at java.awt.Container.processEvent(Container.java:2239) at java.awt.Component.dispatchEventImpl(Component.java:4889) at java.awt.Container.dispatchEventImpl(Container.java:2297) at java.awt.Component.dispatchEvent(Component.java:4711) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4904) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4535) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4476) at java.awt.Container.dispatchEventImpl(Container.java:2283) at java.awt.Window.dispatchEventImpl(Window.java:2746) at java.awt.Component.dispatchEvent(Component.java:4711) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:84) at java.awt.EventQueue$4.run(EventQueue.java:733) at java.awt.EventQueue$4.run(EventQueue.java:731) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.awt.EventQueue.dispatchEvent(EventQueue.java:730) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
首先引入依赖
<!-- https://mvnrepository.com/artifact/org.bytedeco.javacpp-presets/opencv --> <dependency> <groupId>org.bytedeco.javacpp-presets</groupId> <artifactId>opencv</artifactId> <version>4.0.1-1.4.4</version> </dependency>
再去官网下载一些东东https://opencv.org/releases/
因为maven仓的版本 最高只有4.0.1所以，下载的时候，找到4.0.1下载
官网下载资源
然后运行，解压后会得到一些文件
然后把dll扔到jdk的bin文件夹下
这个路径具体看自己的实际情况
然后构建一下，看到有这个jar包就行了，
开始之前呢，需要先了解一下opencv的行列方向问题
一般图片都需要进行灰度化然后二值化，
参考下图
这样基本上也可以识别了，但是还是有一些噪点，最好还是去一下噪点
对于分辨率比较低的图片，噪点基本都是一两个像素
简单的办法就是计算黑色像素点周围的8个像素是不是全部白色，如果是那8个像素点的值加起来就是2040，就把这个点处理成白色，如果不是，那可能就不是噪点
效果还凑合
代码如下
//因为去了边框，所以，行列数，做减2处理，即不处理边框上的像素 for(int x=1;x<col-1;x++){ for(int y=1;y<row-1;y++){ double[] binDataList=target.get(y, x); double binData=binDataList[0]; if(binData==0){//黑色 double[] x1list=target.get(y-1, x-1); double[] x2list=target.get(y-1, x); double[] x3list=target.get(y-1, x+1); double[] x4list=target.get(y, x-1); double[] x6list=target.get(y, x+1); double[] x7list=target.get(y+1, x-1); double[] x8list=target.get(y+1, x); double[] x9list=target.get(y+1, x+1); double x1=x1list[0]; double x2=x2list[0]; double x3=x3list[0]; double x4=x4list[0]; double x6=x6list[0]; double x7=x7list[0]; double x8=x8list[0]; double x9=x9list[0]; if(x1+x2+x3+x4+x6+x7+x8+x9>=2040){ System.out.println("坐标xy："+x+","+y+"此点是噪点，抹除处理"); target.put(y, x, 255);//画一个白点 } } else{ } } }
稍微复杂一点的有连通域计算面积办法
https://blog.csdn.net/marooon/article/details/81332487
