/**
 * 根據圖片路徑，獲取該該圖片的每個像素點并保存到對應的二維數組中
 * @param path 圖片路徑
 * @return 保存像素點的二維數組
 */
 public int[][] getImgPixel(String path){
 File file = new File(path);
 BufferedImage buffImg = null; //緩沖圖片
 try {
  buffImg = ImageIO.read(file);
 } catch (IOException e) {
  e.printStackTrace();
 }
 int w = buffImg.getWidth();
 int h = buffImg.getHeight();
 //定義二維數組，保存像素點
 int[][] pixelArray = new int[w][h];
 //讀取每個位置的像素點
 for(int i=0;i<w;i++){
  for(int j=0;j<h;j++){
  int pixel = buffImg.getRGB(i, j); //獲取每個位置像素值
  pixelArray[i][j] = pixel;
  }
 }
 return pixelArray;
 }

 //原圖
 public void drawImg(String path, Graphics gr){
   //得到圖片路徑
 int[][] img = getImgPixel(path);
 for(int i=0;i<img.length;i++){
  for(int j=0;j<img[i].length;j++){
  int pixel = img[i][j];
  //原圖顏色不變
  Color c = new Color(pixel);
   gr.setColor(c);
   //使用rectangle填充每一個點
   gr.fillRect(i, j, 1,1);
  }
 }
 }

 //黑白
 public void drawBw(String path, Graphics gr){
 int [][] img = getImgPixel(path);
 // 此處buffG為存儲圖片做準備
 buffG = new BufferedImage(img.length, img[0].length, 1);
 Graphics buff=buffG.getGraphics();

 for(int i=0; i<img.length; i++){
  for(int j=0; j<img[i].length; j++){
  int pixel =img[i][j];
  Color c = new Color(pixel);
  int r=c.getRed(); int g=c.getGreen(); int b=c.getBlue();
  //將小于某一值的顏色作為界限區(qū)分黑白
  if(b<100){
   buff.setColor(Color.BLACK);
  }else {
   buff.setColor(Color.white);
  }
  buff.fillRect(i,j,3,3);
  }
 }
 gr.drawImage(buffG,0,0,null);
 }

 //馬賽克實現
 public void drawPixel(String path, Graphics gr){
 int[][] pixelArray = getImgPixel(path);
 buffG = new BufferedImage(pixelArray.length, pixelArray[0].length, 1);
 Graphics buff=buffG.getGraphics();
 //減少像素數量
 for(int i=0;i<pixelArray.length;i+=10){
  for(int j=0;j<pixelArray[0].length;j+=10){
  int pixel = pixelArray[i][j];
  Color color = new Color(pixel);
  buff.setColor(color);
  //放大像素點大小
  buff.fillRect(i, j, 10, 10);
  }
 }
 gr.drawImage(buffG,0,0,null);
 }

 //灰度圖實現
 public void drawGrayScale(String path, Graphics gr){
 int[][] img = getImgPixel(path);
 buffG = new BufferedImage(img.length, img[0].length, 1);
 Graphics buff=buffG.getGraphics();

 for(int i=0; i<img.length;i++){
  for(int j=0;j<img[i].length;j++) {
  int pixel =img[i][j];
  Color c = new Color (pixel);
  // 取rgp平均值
  int r = c.getRed();
  int g = c.getGreen();
  int b = c.getBlue();
  int sum = (r+g+b)/3;
  Color newc= new Color(sum,sum,sum);
  buff.setColor(newc);
  buff.fillRect(i,j,1,1);
  }
 }
 gr.drawImage(buffG,0,0,null);
 }

//去背景實現
 public void drawRemoveBg(String path, Graphics gr){
 int[][] img = getImgPixel(path);
 buffG = new BufferedImage(img.length, img[0].length, 1);
 Graphics buff=buffG.getGraphics();
 for(int i=0;i<img.length;i++){
  for(int j=0;j<img[i].length;j++){
  int pixel = img[i][j];
  Color c = new Color(pixel);
  //去背景，只畫大于某一值的顏色去背景效果
  int r=c.getRed();int g=c.getGreen();int b=c.getBlue();
  if(g>150){
   Color nc=new Color(r,g,b);
   buff.setColor(nc);
   buff.fillRect(i, j, 1,1);
  }
  }
 }
 gr.drawImage(buffG,0,0,null);
 }

 //網格化實現
 public void drawGrid(String path, Graphics gr){
 int [][] img = getImgPixel(path);
 buffG = new BufferedImage(img.length, img[0].length, 1);
 Graphics buff=buffG.getGraphics();

 //減少像素數量
 for(int i=0;i<img.length;i+=10){
  for(int j=0;j<img[i].length;j+=10){
  int pixel = img[i][j];
  Color c = new Color(pixel);
  int r=c.getRed(); int g=c.getGreen(); int b=c.getBlue();
  Color nc = new Color(r,g,b);
  buff.setColor(nc);
  //放大像素數量
  buff.fillOval(i, j, 8,8 );
  }
 }
 gr.drawImage(buffG,0,0,null);
 }

//油畫效果
 public void drawPainting(String path, Graphics gr){
 int[][] img =getImgPixel(path);
 buffG = new BufferedImage(img.length, img[0].length, 1);
 Graphics buff=buffG.getGraphics();
 for(int i=0; i<img.length; i++){
  for(int j=0; j<img[i].length; j++){
  int pixel = img[i][j];
  Color c = new Color(pixel);
  buff.setColor(c);
  ///填充隨機大小癿色塊
  Random random =new Random();
  int r = random.nextInt(20)+5;
  buff.fillOval(i,j,r,r);
  }
 }
 gr.drawImage(buffG,0,0,null);
 }

 //雙圖
 public void drawDouble(String path1, String path2, Graphics gr ){

 //選取a,b兩張照片, 給顏色不同權值
 int[][] img1=getImgPixel(path1);
 int[][] img2=getImgPixel(path2);
 // 取其寬高癿最小值，防數組越界
 int w =Math.min(img1.length,img2.length);
 int h =Math.min(img1[0].length, img2.length);
 buffG = new BufferedImage(w,h, 1);
 Graphics buff=buffG.getGraphics();
 //更大的圖片在前循環(huán)
 for(int i=0; i<w; i+=1){
  for(int j=0;j<h;j+=1){
  Color c1 = new Color(img1[i][j]);
  Color c2 = new Color(img2[i][j]);
  //透明處理
  int r=(int)(c1.getRed()*0.7+c2.getRed()*0.3);
  int g=(int)(c1.getGreen()*0.3+c2.getGreen()*0.7);
  int b=(int)(c1.getBlue()*0.3+c2.getBlue()*0.7);
  Color cn = new Color(r,g,b);
  buff.setColor(cn);
  buff.drawLine(i,j,i,j);
  }
 }
 gr.drawImage(buffG,0,0,null);
 }

 //卷積核癿二維數組：邊緣化
 float[][] kArray= {{-1,-1,-1,-1,-1},
   {-1,-1,-1,-1,-1},{-1,-1,25,-1,-1},
   {-1,-1,-1,-1,-1},{-1,-1,-1,-1,-1}};
 /**
 * 卷積計算
 * @param src :圖片數組
 * @param filter :卷積核數組
 * @return 計算后癿數組
 */
 public static int[][] valide(int[][] src,float[][] filter){
 int[][]tem = new int[filter.length][filter[0].length];
 int valideWidth = src[0].length - filter[0].length+1;
 int valideheight = src.length - filter.length+1;
 int[][] valide = new int[valideheight][valideWidth];
 for(int i=0;i<valideheight;i+=1){
  for(int j=0;j<valideWidth;j+=1){
  for(int y=0;y<filter.length;y++){
   for(int z=0;z<filter[0].length;z++){
   tem[y][z] =(int)((src[i+y][j+z])*(filter[y][z]));
   }
  }
  int kk=0;
  for(int y=0;y<filter.length;y++){
   for(int z=0;z<filter[0].length;z++){
   kk += tem[y][z];
   }
  }
  if(kk<0)kk=0; if(kk>255)kk=255;
  valide[i][j]=(byte)kk;
  }
 }
 return valide;
 }

 //卷積效果
 public void drawJJ(String path){
 DrawMouse mouse= new DrawMouse();
 int[][] ia= mouse.getImgPixel(path);
 ia=valide(ia, kArray);
 buffG = new BufferedImage(ia.length, ia[0].length, 1);
 Graphics buff=buffG.getGraphics();
 for(int i=0;i<ia.length;i++){
  for(int j=0;j<ia[0].length;j++){
  int pixel = ia[i][j];
  Color color = new Color(pixel);
  buff.setColor(color);
  //放大像素點大小 保證減少的倍數與放大倍數相同，否則是網格化
  buff.fillRect(i, j, 10, 10);
  }
 }
 //在界面上畫出ia數組圖像，即卷積結果：
 gr.drawImage(buffG,0,0,null);
 }

public void openFile(){
 JFileChooser jfc = new JFileChooser();
 jfc.setAcceptAllFileFilterUsed(false);//取消顯示所有文件過濾選項
 //后綴名過濾器
 FileNameExtensionFilter filter = new FileNameExtensionFilter("(*.jpg)", "jpg");
 jfc.setFileFilter(filter);
 jfc.setDialogTitle("打開文件");
 jfc.showOpenDialog(null);
 File file = jfc.getSelectedFile();
 if(file!=null){
  fPath=file.getPath();
  System.out.print(fPath);
  drawImg(fPath, gr);
 }else {
  System.out.println("未選擇文件");
 }
 }

 public void saveFile(){
 JFileChooser jfc = new JFileChooser();
 //后綴名過濾器
 FileNameExtensionFilter filter = new FileNameExtensionFilter(
   "(*.jpg)", "jpg");
 jfc.setFileFilter(filter);
 jfc.setDialogTitle("保存文件");
 jfc.showSaveDialog(null);
 File file = jfc.getSelectedFile();
 try {
  ImageIO.write(buffG,"jpg", file);
  System.out.print("保存成功" );
 } catch (IOException ex) {
  ex.printStackTrace();
 }
 }

// 聲明List類型集合變量list，使用ArrayList類實例化list，List接口不能實例化
List list = new ArrayList();
String b = "B";

list.add("A");
list.add(b);

list.clear(); // [] 清空集合，變量list所引用的對象還在，不是null，只是集合中沒有了元素
list.add(1); // 發(fā)生自動裝箱
int item = (Integer)list.get(0); // 發(fā)生自動拆箱

for (int i = 0; i < list.size(); i++) {
  System.out.println(i, list.gei(i));
}

for (Object item : list) {
  String s = (String) item;
  System.out.println(s);
}

Iterator it = list.iterator(); // 迭代器對象
while (it.hasNext()) { // 判斷集合中是否還有元素可以迭代，有true，沒有false
  Object item = it.next(); // 返回迭代的下一元素
  String s = (String) item;
  System.out.println(s);
}

Map map = new HashMap();

map.put(102, "張三")；
map.put(105, "李四")；
map.put(102, "王五")； // 102鍵已存在，替換原來值

map.get(102); // 王五
map.clear(); // {}

Set keys = map.keySet();
for (Object key : keys) {
  int ikey = (Integer) key; // 自動拆箱
  String value = (String) map.get(ikey); // 自動拆箱
}

Collection values = map.values(); // 獲得值集合
Iterator it = values.iterator(); // 遍歷值集合
while (it.hasNext()) {
  Object item = it.next();
  String s = (String) item;
}