Mega Code Archive
Gray scale image operation
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/*
* Copyright (c) 2000 David Flanagan. All rights reserved.
* This code is from the book Java Examples in a Nutshell, 2nd Edition.
* It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
* You may study, use, and modify it for any non-commercial purpose.
* You may distribute it non-commercially as long as you retain this notice.
* For a commercial use license, or to purchase the book (recommended),
* visit http://www.davidflanagan.com/javaexamples2.
*/
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.color.ColorSpace;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import java.awt.image.ByteLookupTable;
import java.awt.image.ColorConvertOp;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import java.awt.image.LookupOp;
import java.awt.image.RescaleOp;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.net.URL;
import javax.swing.JFrame;
import javax.swing.JPanel;
/** A demonstration of various image processing filters */
public class ImageOps extends JPanel {
static final int WIDTH = 600, HEIGHT = 675; // Size of our example
public String getName() {
return "Image Processing";
}
public int getWidth() {
return WIDTH;
}
public int getHeight() {
return HEIGHT;
}
Image image;
/** This constructor loads the image we will manipulate */
public ImageOps() {
image = Toolkit.getDefaultToolkit().getImage("a.jpg");
}
// These arrays of bytes are used by the LookupImageOp image filters below
static byte[] brightenTable = new byte[256];
static byte[] thresholdTable = new byte[256];
static { // Initialize the arrays
for (int i = 0; i < 256; i++) {
brightenTable[i] = (byte) (Math.sqrt(i / 255.0) * 255);
thresholdTable[i] = (byte) ((i < 225) ? 0 : i);
}
}
// This AffineTransform is used by one of the image filters below
static AffineTransform mirrorTransform;
static { // Create and initialize the AffineTransform
mirrorTransform = AffineTransform.getTranslateInstance(127, 0);
mirrorTransform.scale(-1.0, 1.0); // flip horizontally
}
// These are the labels we'll display for each of the filtered images
static String[] filterNames = new String[] { "Original", "Gray Scale", "Negative", "Brighten (linear)", "Brighten (sqrt)", "Threshold", "Blur", "Sharpen", "Edge Detect", "Mirror", "Rotate (center)", "Rotate (lower left)" };
// The following BufferedImageOp image filter objects perform
// different types of image processing operations.
static BufferedImageOp[] filters = new BufferedImageOp[] {
// 1) No filter here. We'll display the original image
null,
// 2) Convert to Grayscale color space
new ColorConvertOp(ColorSpace.getInstance(ColorSpace.CS_GRAY), null),
// 3) Image negative. Multiply each color value by -1.0 and add 255
new RescaleOp(-1.0f, 255f, null),
// 4) Brighten using a linear formula that increases all color
// values
new RescaleOp(1.25f, 0, null),
// 5) Brighten using the lookup table defined above
new LookupOp(new ByteLookupTable(0, brightenTable), null),
// 6) Threshold using the lookup table defined above
new LookupOp(new ByteLookupTable(0, thresholdTable), null),
// 7) Blur by "convolving" the image with a matrix
new ConvolveOp(new Kernel(3, 3, new float[] { .1111f, .1111f, .1111f, .1111f, .1111f, .1111f, .1111f, .1111f, .1111f, })),
// 8) Sharpen by using a different matrix
new ConvolveOp(new Kernel(3, 3, new float[] { 0.0f, -0.75f, 0.0f, -0.75f, 4.0f, -0.75f, 0.0f, -0.75f, 0.0f })),
// 9) Edge detect using yet another matrix
new ConvolveOp(new Kernel(3, 3, new float[] { 0.0f, -0.75f, 0.0f, -0.75f, 3.0f, -0.75f, 0.0f, -0.75f, 0.0f })),
// 10) Compute a mirror image using the transform defined above
new AffineTransformOp(mirrorTransform, AffineTransformOp.TYPE_BILINEAR),
// 11) Rotate the image 180 degrees about its center point
new AffineTransformOp(AffineTransform.getRotateInstance(Math.PI, 64, 95), AffineTransformOp.TYPE_NEAREST_NEIGHBOR),
// 12) Rotate the image 15 degrees about the bottom left
new AffineTransformOp(AffineTransform.getRotateInstance(Math.PI / 12, 0, 190), AffineTransformOp.TYPE_NEAREST_NEIGHBOR), };
/** Draw the example */
public void paint(Graphics g1) {
Graphics2D g = (Graphics2D) g1;
// Create a BufferedImage big enough to hold the Image loaded
// in the constructor. Then copy that image into the new
// BufferedImage object so that we can process it.
BufferedImage bimage = new BufferedImage(image.getWidth(this), image.getHeight(this), BufferedImage.TYPE_INT_RGB);
Graphics2D ig = bimage.createGraphics();
ig.drawImage(image, 0, 0, this); // copy the image
// Set some default graphics attributes
g.setFont(new Font("SansSerif", Font.BOLD, 12)); // 12pt bold text
g.setColor(Color.green); // Draw in green
g.translate(10, 10); // Set some margins
// Loop through the filters
for (int i = 0; i < filters.length; i++) {
// If the filter is null, draw the original image, otherwise,
// draw the image as processed by the filter
if (filters[i] == null)
g.drawImage(bimage, 0, 0, this);
else
g.drawImage(filters[i].filter(bimage, null), 0, 0, this);
g.drawString(filterNames[i], 0, 205); // Label the image
g.translate(137, 0); // Move over
if (i % 4 == 3)
g.translate(-137 * 4, 215); // Move down after 4
}
}
public static void main(String[] a) {
JFrame f = new JFrame();
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
f.setContentPane(new ImageOps());
f.pack();
f.setVisible(true);
}
}
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