Question

java图像旋转顺时针90度的问题

void xuanzhuan90_actionPerformed(ActionEvent e){
try {
Image ia=ic.getImage();
int width = ia.getWidth(this);
int height = ia.getHeight(this);
int pixels[] = new int [width * height];
PixelGrabber pg = new PixelGrabber(ia, 0, 0, width, height, pixels, 0, width);
if (pg.grabPixels() && ((pg.status()& ImageObserver.ALLBITS) !=0)) {
k = createImage(new MemoryImageSource(height,width, colFlipPixels(pixels, width, height), 0, width));
}
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
ImageIcon ica=new ImageIcon(k);
jLabel1.setIcon(ica);
repaint();
}
private int[] colFlipPixels(int pixels[], int width, int height) {
int newPixels[] = null;
if ((width * height) == pixels.length) {
newPixels = new int[width * height];
int newIndex = 0;
for (int y = 0; y < height; y++)
for (int x = width - 1; x >= 0; x--)
newPixels[newIndex++] = pixels[y * width + x];
}

return newPixels;
}
以上是旋转90度的代码，还有180度的和270度的，和以上基本一样，就是在循环嵌套那里有明显区别，但180度和270度是可以实现的，90度的实现不了，求高手指点！提前谢过了啊！

Answer 1

import javax.swing.*;

import javax.imageio.*;

import java.awt.*;

import java.awt.image.*;

import java.awt.geom.*;

import java.io.*;

/**

 * @author Hardneedl

 */

class ImageTransform extends JFrame {

    private static final Dimension minSize = new Dimension(900, 800);

    private static final Dimension maxSize = new Dimension(900, 800);

    private static final Dimension preferredSize = new Dimension(900, 800);

    public Dimension getMaximumSize() {return maxSize;}

    public Dimension getMinimumSize() {return minSize;}

    public Dimension getPreferredSize() {return preferredSize;}

    public String getTitle() {return "Frame Title";}

    private class Canvas extends JComponent{

        private BufferedImage img;

        private AffineTransform trans=new AffineTransform();

        private void setImage(BufferedImage img){

            if(img!=null) this.img = img;

            if(isVisible())  paintImmediately(0,0,getWidth(),getHeight());

        }

        private void setRota(double rota){

            trans.setToRotation(rota, (getWidth())>>1, ( getHeight()  )>>1 );

            if(isVisible())  paintImmediately(0,0,getWidth(),getHeight());

        }

        protected void paintComponent(Graphics g) {

            super.paintComponent(g);

            g.setColor(Color.BLUE);

            g.fillRect(0,0,getWidth(),getHeight());

            if (img==null)return;

            Graphics2D gg= (Graphics2D)g.create();

            int iw = img.getWidth(), ih = img.getHeight();

            int anchorX = (getWidth()- iw)>>1, anchorY = (getHeight() - ih)>>1;

            AffineTransform af = gg.getTransform();

            af.translate(anchorX, anchorY);

            af.concatenate(trans);

            gg.drawImage(img,af,this);

            gg.dispose();

        }

    }

    private Canvas canvas = new Canvas();

    ImageTransform() throws HeadlessException {

        init();

        doLay();

        attachListeners();

    }

    private void init() {

        try {

            canvas.setImage(ImageIO.read(new File("1.png")));

            canvas.setRota(Math.PI/3);

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

    private void doLay() {

        Container container = getContentPane();

        container.add(canvas,BorderLayout.CENTER);

        pack();

    }

    private void attachListeners() {

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }

    public static void main(String[] args) throws IOException {

        new ImageTransform().setVisible(true);

    }

}

Answer 2

这个问题我以前遇到过，我是模仿windows中的图片查看器写的，具体怎么样我也不清楚了，你要的话给我留言，并注明要什么，我是开源的，呵呵