如何使用Java將影象轉換為灰度?

2019-10-16 22:26:12

在Java語言程式設計中,如何使用Java將圖片轉換為灰度?

注意:需要存取網址:http://book2s.com/java/jar/o/opencv/download-opencv-3.2.0-0.html , 下載一個OpenCV軟體包。這裡下載最新版本:opencv-3.2.0-vc14.exe並解壓此檔案到D:\software\opencv目錄中。

專案結構如下圖所示 -

新增一個使用者自定義庫:OpenCV3.2,並指組態構建路徑為:D:\software\opencv\opencv\build\java\x64,如下圖所示 -

註:可參考: http://blog.csdn.net/shawncheer/article/details/51098456

以下是使用Java將影象轉換為灰度的程式 -

package com.yiibai;

import org.opencv.core.Core;
import org.opencv.core.Mat;

import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

public class ConvertingImageToGrayScale {
   public static void main(String args[]) throws Exception {

      //Loading the OpenCV core library
      System.loadLibrary(Core.NATIVE_LIBRARY_NAME );
      String input = "images/zhonglou.jpg";

      //Reading the image
      Mat src = Imgcodecs.imread(input);

      //Creating the empty destination matrix
      Mat dst = new Mat();

      //Converting the image to gray scale and saving it in the dst matrix
      Imgproc.cvtColor(src, dst, Imgproc.COLOR_RGB2GRAY);

      //Writing the image
      Imgcodecs.imwrite("images/zhonglouToGrayScale.jpg", dst);
      System.out.println("Converted to Grayscale");
   }
}

執行上面範例程式碼,得到以下結果 -

Converted to Grayscale

原圖 -

海口鐘樓

在執行上面範例程式碼成功後,應該會在 F:\worksp\javaexamples\java_opencv\images 目錄中有看到生成一個檔案:zhonglouToGrayScale.jpg

問題

F:\worksp\javaexamples\java_opencv
Exception in thread "main" java.lang.UnsatisfiedLinkError: no opencv_java320 in java.library.path
    at java.lang.ClassLoader.loadLibrary(Unknown Source)
    at java.lang.Runtime.loadLibrary0(Unknown Source)
    at java.lang.System.loadLibrary(Unknown Source)
    at com.yiibai.CopyAndPasteAnImage.main(CopyAndPasteAnImage.java:13)

解決上述問題可通過參考: http://blog.csdn.net/shawncheer/article/details/51098456