【发布时间】：2013-12-14 22:26:17
【问题描述】：
经过深入搜索后，我无法理解为什么我的结果图像与来自维基百科的图像相比不是我所期望的 - sobel 运算符使用相同的内核作为 Sobel 运算符。
http://s29.postimg.org/kjex7dx6f/300px_Valve_original_1.png
http://s14.postimg.org/vxhvffm29/Untitled.png
所以，我有一个按钮监听器，可以加载 bmp 图像、应用 Sobel 并显示 ImageIcon 有代码：
javax.swing.JFileChooser choose = new javax.swing.JFileChooser();
choose.setFileFilter(new DoFileFilter(".bmp"));
int returnVal = choose.showOpenDialog(this);
if (returnVal == javax.swing.JFileChooser.APPROVE_OPTION) {
try {
java.io.FileInputStream imgis = null;
// System.out.println("Ai ales fisierul : " +
// choose.getSelectedFile());
String path = choose.getSelectedFile().toString();
Path.setText(path);
imgis = new java.io.FileInputStream(path);
java.awt.image.BufferedImage img = javax.imageio.ImageIO.read(imgis);
DirectImgToSobel ds = new DirectImgToSobel(img);
javax.swing.ImageIcon image;
image = new javax.swing.ImageIcon(ds.getBuffImg());
ImgPrev.setIcon(image);
javax.swing.JFrame frame = (javax.swing.JFrame) javax.swing.SwingUtilities.getWindowAncestor(jPanel1);
frame.pack();
frame.repaint();
} catch (FileNotFoundException ex) {
Logger.getLogger(Display.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(Display.class.getName()).log(Level.SEVERE, null, ex);
}
}
还有索贝尔课：
public class DirectImgToSobel {
private final java.awt.image.BufferedImage img;
private java.awt.image.BufferedImage buffimg;
private int[][]
sobel_x = { { -1, 0, 1 }, { -2, 0, 2 }, { -1, 0, 1 } },
sobel_y = { { -1, -2, -1 }, { 0, 0, 0 }, { 1, 2, 1 } };
public DirectImgToSobel() {
this.img = null;
}
public DirectImgToSobel(java.awt.image.BufferedImage img) {
this.img = img;
aplicaFiltru();
}
private void aplicaFiltru() {
this.buffimg = new java.awt.image.BufferedImage(this.img.getWidth(), this.img.getHeight(),
java.awt.image.BufferedImage.TYPE_BYTE_GRAY);
for (int x = 1; x < this.img.getWidth() - 1; x++) {
for (int y = 1; y < this.img.getHeight() - 1; y++) {
int pixel_x =
(sobel_x[0][0] * img.getRGB(x-1,y-1)) + (sobel_x[0][1] * img.getRGB(x,y-1)) + (sobel_x[0][2] * img.getRGB(x+1,y-1)) +
(sobel_x[1][0] * img.getRGB(x-1,y)) + (sobel_x[1][1] * img.getRGB(x,y)) + (sobel_x[1][2] * img.getRGB(x+1,y)) +
(sobel_x[2][0] * img.getRGB(x-1,y+1)) + (sobel_x[2][1] * img.getRGB(x,y+1)) + (sobel_x[2][2] * img.getRGB(x+1,y+1));
int pixel_y =
(sobel_y[0][0] * img.getRGB(x-1,y-1)) + (sobel_y[0][1] * img.getRGB(x,y-1)) + (sobel_y[0][2] * img.getRGB(x+1,y-1)) +
(sobel_y[1][0] * img.getRGB(x-1,y)) + (sobel_y[1][1] * img.getRGB(x,y)) + (sobel_y[1][2] * img.getRGB(x+1,y)) +
(sobel_y[2][0] * img.getRGB(x-1,y+1)) + (sobel_y[2][1] * img.getRGB(x,y+1)) + (sobel_y[2][2] * img.getRGB(x+1,y+1));
this.buffimg.setRGB(x, y, (int) Math.sqrt(pixel_x * pixel_x + pixel_y * pixel_y));
}
}
buffimg = thresholdImage(buffimg, 28);
java.awt.Graphics g = buffimg.getGraphics();
g.drawImage(buffimg, 0, 0, null);
g.dispose();
}
public java.awt.image.BufferedImage getBuffImg() {
return this.buffimg;
}
public static java.awt.image.BufferedImage thresholdImage(java.awt.image.BufferedImage image, int threshold) {
java.awt.image.BufferedImage result = new java.awt.image.BufferedImage(image.getWidth(), image.getHeight(),
java.awt.image.BufferedImage.TYPE_BYTE_GRAY);
result.getGraphics().drawImage(image, 0, 0, null);
java.awt.image.WritableRaster raster = result.getRaster();
int[] pixels = new int[image.getWidth()];
for (int y = 0; y < image.getHeight(); y++) {
raster.getPixels(0, y, image.getWidth(), 1, pixels);
for (int i = 0; i < pixels.length; i++) {
if (pixels[i] < threshold)
pixels[i] = 0;
else
pixels[i] = 255;
}
raster.setPixels(0, y, image.getWidth(), 1, pixels);
}
return result;
}
}
【问题讨论】：