Java读取并修改图片的像素值

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Java程序读取图片像素的值类，

package work;import java.awt.AWTException;import java.awt.Dimension;import java.awt.Rectangle;import java.awt.Robot;import java.awt.Toolkit;import java.awt.image.BufferedImage;import java.io.File;import javax.imageio.ImageIO;public class Image {    /**     * 读取一张图片的RGB值     *      * @throws Exception     */    public void getImagePixel(String image) throws Exception {        int[] rgb = new int[3];        File file = new File(image);        BufferedImage bi = null;        try {            bi = ImageIO.read(file);        } catch (Exception e) {            e.printStackTrace();        }        int width = bi.getWidth();        int height = bi.getHeight();        int minx = bi.getMinX();        int miny = bi.getMinY();        System.out.println("width=" + width + ",height=" + height + ".");        System.out.println("minx=" + minx + ",miniy=" + miny + ".");        for (int i = minx; i < width; i++) {            for (int j = miny; j < height; j++) {                int pixel = bi.getRGB(i, j); // 下面三行代码将一个数字转换为RGB数字                rgb[0] = (pixel & 0xff0000) >> 16;                rgb[1] = (pixel & 0xff00) >> 8;                rgb[2] = (pixel & 0xff);                System.out.println("i=" + i + ",j=" + j + ":(" + rgb[0] + ","                        + rgb[1] + "," + rgb[2] + ")");                bi.setRGB(123, 123, 123);            }        }    }    /**     * 返回屏幕色彩值     *      * @param x     * @param y     * @return     * @throws AWTException     */    public int getScreenPixel(int x, int y) throws AWTException { // 函数返回值为颜色的RGB值。        Robot rb = null; // java.awt.image包中的类，可以用来抓取屏幕，即截屏。        rb = new Robot();        Toolkit tk = Toolkit.getDefaultToolkit(); // 获取缺省工具包        Dimension di = tk.getScreenSize(); // 屏幕尺寸规格        System.out.println(di.width);        System.out.println(di.height);        Rectangle rec = new Rectangle(0, 0, di.width, di.height);        BufferedImage bi = rb.createScreenCapture(rec);        int pixelColor = bi.getRGB(x, y);        return 16777216 + pixelColor; // pixelColor的值为负，经过实践得出：加上颜色最大值就是实际颜色值。    }    /**     * @param args     */    public static void main(String[] args) throws Exception {        int x = 0;        Image rc = new Image();        x = rc.getScreenPixel(100, 345);        System.out.println(x + " - ");        rc.getImagePixel("D:\\xiao.jpg");    }}

Java读取并修改像素的值。

package work;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.ByteArrayOutputStream;import java.io.File;import javax.imageio.ImageIO;import javax.swing.ImageIcon;public class Image1 {     private void setAlpha(String os) {            /**             * 增加测试项             * 读取图片，绘制成半透明,修改像素             */            try {              ImageIcon imageIcon = new ImageIcon(os);              BufferedImage bufferedImage = new BufferedImage(imageIcon.getIconWidth(),imageIcon.getIconHeight()                  , BufferedImage.TYPE_4BYTE_ABGR);              Graphics2D g2D = (Graphics2D) bufferedImage.getGraphics();              g2D.drawImage(imageIcon.getImage(), 0, 0,                                   imageIcon.getImageObserver());              //循环每一个像素点，改变像素点的Alpha值              int alpha = 100;              for (int j1 = bufferedImage.getMinY(); j1 < bufferedImage.getHeight(); j1++) {                for (int j2 = bufferedImage.getMinX(); j2 < bufferedImage.getWidth(); j2++) {                  int pixel = bufferedImage.getRGB(j2, j1);                  int[]   rgb = new int[3];                  rgb[0] = (pixel & 0xff0000) >> 16;                  rgb[1] = (pixel & 0xff00) >> 8;                  rgb[2] = (pixel & 0xff);                  System.out.println("i=" + j1 + ",j=" + j2 + ":(" + rgb[0] + ","                            + rgb[1] + "," + rgb[2] + ")");                  pixel = ( (alpha + 1) << 24) | (pixel & 0x00ffffff);                  bufferedImage.setRGB(j2, j1, pixel);                }              }              g2D.drawImage(bufferedImage, 0, 0, imageIcon.getImageObserver());              //生成图片为PNG              ImageIO.write(bufferedImage, "jpg",  new File("D:\\xiao.jpg"));            }            catch (Exception e) {              e.printStackTrace();            }          }     public static void main(String[] args) throws Exception {        int x = 0;        Image1 rc = new Image1();        rc.setAlpha("D:\\xiao.jpg");        rc.setAlpha("D:\\xiao.jpg");    }}

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