Java tutorial
/* * 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); } }