Java DIP-Sobel操作员

📌 相关文章

📜 Java DIP-Sobel操作员

📅 最后修改于: 2020-12-14 05:42:03 🧑 作者: Mango

Sobel运算符与Prewitt运算符非常相似。它也是派生掩码，用于边缘检测。 Sobel运算符用于检测图像中的两种边缘：垂直方向边缘和水平方向边缘。

我们将使用OpenCV函数filter2D将Sobel运算符应用于图像。可以在Imgproc软件包下找到。其语法如下-

filter2D(src, dst, depth , kernel, anchor, delta, BORDER_DEFAULT );

函数参数描述如下-

Sr.No.	Argument
1	src It is source image.
2	dst It is destination image.
3	depth It is the depth of dst. A negative value (such as -1) indicates that the depth is the same as the source.
4	kernel It is the kernel to be scanned through the image.
5	anchor It is the position of the anchor relative to its kernel. The location Point (-1, -1) indicates the center by default.
6	delta It is a value to be added to each pixel during the convolution. By default it is 0.
7	BORDER_DEFAULT We let this value by default.

除了filter2D方法之外，Imgproc类还提供其他方法。他们简要描述-

Sr.No.	Method & Description
1	cvtColor(Mat src, Mat dst, int code, int dstCn) It converts an image from one color space to another.
2	dilate(Mat src, Mat dst, Mat kernel) It dilates an image by using a specific structuring element.
3	equalizeHist(Mat src, Mat dst) It equalizes the histogram of a grayscale image.
4	filter2D(Mat src, Mat dst, int depth, Mat kernel, Point anchor, double delta) It convolves an image with the kernel.
5	GaussianBlur(Mat src, Mat dst, Size ksize, double sigmaX) It blurs an image using a Gaussian filter.
6	integral(Mat src, Mat sum) It calculates the integral of an image.

例

下面的示例演示如何使用Imgproc类将Sobel运算符应用于灰度图像。

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

import org.opencv.highgui.Highgui;
import org.opencv.imgproc.Imgproc;

public class convolution {
   public static void main( String[] args ) {
   
      try {
         int kernelSize = 9;
         System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
         
         Mat source = Highgui.imread("grayscale.jpg",  Highgui.CV_LOAD_IMAGE_GRAYSCALE);
         Mat destination = new Mat(source.rows(),source.cols(),source.type());
         
         Mat kernel = new Mat(kernelSize,kernelSize, CvType.CV_32F) {
            {
               put(0,0,-1);
               put(0,1,0);
               put(0,2,1);

               put(1,0-2);
               put(1,1,0);
               put(1,2,2);

               put(2,0,-1);
               put(2,1,0);
               put(2,2,1);
            }
         };          
         
         Imgproc.filter2D(source, destination, -1, kernel);
         Highgui.imwrite("output.jpg", destination);
         
      } catch (Exception e) {
         System.out.println("Error: " + e.getMessage());
      }
   }
}