Java图形与图像处理

第5章 Java图形与图像处理【1】用绘制线段的方法输出一个红色的“王”字。

[解答]：代码如下：import javax.swing.*;import java.awt.*;public class DrawWang extends JFrame {public DrawWang(){super("在窗体上绘制一个王字");}public void paint(Graphics g){g.setColor(Color.red);g.drawLine(10,50,100,50);g.drawLine(10,100,100,100);g.drawLine(10,150,100,150);g.drawLine(60,50,60,150);}public static void main(String[] args) {DrawWang dw = new DrawWang();dw.setSize(150,200);dw.setV isible(true);}}运行效果如下：【2】编写一个程序绘制8个同心圆，各园相差20个像素点。

[解答]：代码如下：import javax.swing.*;import java.awt.*;public class EightCircle extends JFrame {public EightCircle(){super("在窗体上绘制八个同心圆");public void paint(Graphics g){g.setColor(Color.red);g.drawOval(200,200,10,10);g.drawOval(180,180,50,50);g.drawOval(160,160,90,90);g.drawOval(140,140,130,130);g.drawOval(120,120,170,170);g.drawOval(100,100,210,210);g.drawOval(80,80,250,250);g.drawOval(60,60,290,290);}public static void main(String[] args) {EightCircle ec = new EightCircle();ec.setSize(500,400);ec.setVisible(true);}}运行效果如下：【3】编写一个程序绘制一把打开的折扇。

[解答]：代码如下：import javax.swing.*;import java.awt.*;public class T5 extends JFrame {public T5(){super("打开的折扇");public void paint(Graphics g){g.setColor(Color.red);g.fillArc(50,50,300,300,15,150);g.setColor(Color.BLUE);g.fillArc(140,140,120,120,15,150);g.setColor(Color.BLACK);g.fillArc(180,180,40,40,15,150);}public static void main(String[] args) {T5 ec = new T5();ec.setSize(500,400);ec.setVisible(true);}}运行效果如下：【4】改变一副彩色照片的颜色，使之成为黑白照片。

[解答]：代码如下：import javax.swing.*;import java.awt.*;import java.awt.image.PixelGrabber;import java.awt.image.ColorModel;import java.awt.image.ImageProducer;import java.awt.image.MemoryImageSource;public class ConvertToBlack extends JFrame{private Image imgOriginal,imgChanged;private int[] pixels;public ConvertToBlack(){//load original imageimgOriginal = new ImageIcon("src/images/swingo.jpg").getImage();int height = imgOriginal.getHeight(this);int width = imgOriginal.getWidth(this);pixels = new int[width * height];System.out.println(height);//grabber pixels from image to ArrayPixelGrabber grabber = new PixelGrabber(imgOriginal,0,0,width,height,pixels,0,width);try {grabber.grabPixels();} catch (InterruptedException e) {e.printStackTrace();}//change the pixelsColorModel model = ColorModel.getRGBdefault();for (int i = 0; i < pixels.length; i++) {int pixel = pixels[i];int alpha = model.getAlpha(pixel);int gray = (int)(model.getRed(pixel) * 0.3+ model.getGreen(pixel) * 0.59+ model.getBlue(pixel) * 0.11);int red = gray;int green = gray;int blue = gray;pixels[i] = (alpha << 24) | (red << 16) | (green << 8) | blue;}//create new imageImageProducer producer = new MemoryImageSource(width,height,pixels,0,width);imgChanged = createImage(producer);setSize(300,300);setVisible(true);}public static void main(String[] args) {new ConvertToBlack();}public void paint(Graphics g){g.drawImage(imgOriginal,20,20,this);g.drawImage(imgChanged,140,20,this);}}运行效果如下：【5】编写一段产生三维文字的程序。

[解答]：请先安装Java 3D类库，代码如下：import com.sun.j3d.utils.universe.SimpleUniverse;import com.sun.j3d.utils.universe.ViewingPlatform;import com.sun.j3d.utils.behaviors.vp.OrbitBehavior;import javax.media.j3d.*;import javax.vecmath.Point3f;import javax.vecmath.Point3d;import javax.vecmath.Color3f;import javax.vecmath.V ector3f;import java.awt.*;public class Text3DC {private String fontName = "default";private String textString = null;private SimpleUniverse u;private OrbitBehavior orbit;public BranchGroup createSceneGraph(){float sl = textString.length();BranchGroup objRoot = new BranchGroup();TransformGroup objScale = new TransformGroup();Transform3D t3d = new Transform3D();// 设置字体大小t3d.setScale(1.5/sl);objScale.setTransform(t3d);objRoot.addChild(objScale);TransformGroup objTrans = new TransformGroup();objScale.addChild(objTrans);//建立3D字Font3D f3d = new Font3D(new Font(fontName, Font.PLAIN, 2),new FontExtrusion());Text3D txt = new Text3D(f3d,textString,new Point3f(-sl/2.0f, -1.f, -1.f));Shape3D sh = new Shape3D();Appearance app = new Appearance();Material mm = new Material();mm.setLightingEnable(true);app.setMaterial(mm);sh.setGeometry(txt);sh.setAppearance(app);objTrans.addChild(sh);//设置场景的范围BoundingSphere bounds=new BoundingSphere(new Point3d(0.0,0.0,0.0),100.0);//使物体旋转if (false){Transform3D yAxis = new Transform3D();Alpha rotationAlpha = new Alpha(-1, Alpha.INCREASING_ENABLE,0, 0, 4000, 0, 0, 0, 0, 0);RotationInterpolator rotator =new RotationInterpolator(rotationAlpha, objTrans, yAxis,0.0f, (float) Math.PI*2.0f);rotator.setSchedulingBounds(bounds);objTrans.addChild(rotator);}// 设置背景Color3f bgColor = new Color3f(0.15f, 0.15f, 0.5f);Background bgNode = new Background(bgColor);bgNode.setApplicationBounds(bounds);objRoot.addChild(bgNode);// 设置环境光源Color3f ambientColor = new Color3f(0.9f, 0.9f, 0.9f);AmbientLight ambientLightNode = new AmbientLight(ambientColor);ambientLightNode.setInfluencingBounds(bounds);objRoot.addChild(ambientLightNode);// 设置光源方向Color3f light1Color = new Color3f(1.0f, 1.0f, 0.9f);V ector3f light1Direction = new V ector3f(1.0f, 1.0f, 1.0f);Color3f light2Color = new Color3f(1.0f, 1.0f, 0.9f);V ector3f light2Direction = new V ector3f(-1.0f, -1.0f, -1.0f);DirectionalLight light1= new DirectionalLight(light1Color, light1Direction);light1.setInfluencingBounds(bounds);objRoot.addChild(light1);DirectionalLight light2= new DirectionalLight(light2Color, light2Direction);light2.setInfluencingBounds(bounds);objRoot.addChild(light2);return objRoot;}public Text3DC(){textString = "Java3D";BranchGroup scene = createSceneGraph();u = new SimpleUniverse();//在虚拟空间中添加鼠标行为V iewingPlatform viewingPlatform = u.getViewingPlatform();viewingPlatform.setNominalViewingTransform();//设置鼠标控制orbit = new OrbitBehavior();BoundingSphere bounds =new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 100.0);orbit.setSchedulingBounds(bounds);viewingPlatform.setV iewPlatformBehavior(orbit);u.addBranchGraph(scene);}public static void main(String[] args) {new Text3DC();}}运行效果如下：。