RGB 值总是返回相同的像素，即使样本说它不是

Question

我这里有一个名为 blackWhite 的缓冲区图像，它完全是黑色或白色。我在这里尝试做的是我获取一个二维像素坐标数组（在本例中为tog）并找出它是黑色还是白色，将其分配为黑色的0，如果不是，则将其保存回来到二维数组的第三列。虽然它没有出现任何错误，但它并没有给我正确的颜色，并且当我知道它不是白色时说它都是白色的。在这种情况下，我使用 DDA 来选择 2 个点击点之间的每个像素的坐标，这就是这里的数组 tog 中的内容。即使我只选择黑到黑像素，它仍然说一切都是白色的。

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;

public class W3_Img_Process_Class_Only extends JPanel {
    //--------------variables
    int[][] tog;    int step;
    String inTitle="L1";
    int imageCount=0;
    int[] x= new int[2], y= new int[2];
    int[] black= new int[2]; //-------------if black is 0, then the pixel is black
    int clr;    int flag=0;
    
    private BufferedImage master;
    private BufferedImage blackWhite;        

    public W3_Img_Process_Class_Only() {
        //----------------------try/catch for (pure black || pure white)
        try {
            master = ImageIO.read(new File(Image_Path));
            blackWhite = new BufferedImage(master.getWidth(), master.getHeight(), BufferedImage.TYPE_BYTE_BINARY);
            Graphics2D g2d = blackWhite.createGraphics();
            g2d.drawImage(master, 0, 0, this);
            g2d.dispose();
        }catch (IOException ex) {ex.printStackTrace();}
        //--------------------------1st and 2nd click point data and color
            this.addMouseListener(new MouseListener() {
                int[] isFristEmpty;
                @Override
                public void mouseClicked(MouseEvent e1) {
                        int[] temp =new int[3];     //external container so i can get 1st and 2nd separately
                        temp[0] = (int) e1.getX();
                        temp[1] = (int) e1.getY();
                        clr = blackWhite.getRGB(temp[0], temp[1]);
                        temp[2] = (clr & 0x00ff0000) >> 16;//--------------------bit map to find if red is there or not.
                        //-------------------------------------------------------since its pure b/w, if red 0, its white.
                        if(isFristEmpty==null) {
                            isFristEmpty=temp;
                            x[0] = temp[0]; y[0] = temp[1]; black[0]=temp[2];//------1st click
                        }else {
                            x[1] = temp[0]; y[1] = temp[1]; black[1]=temp[2];//-----2nd click
                            isFristEmpty=null;  //so the 3rd click is considered 1st click again
                            flag=1;
                        }
                        if (flag==1) {
                            
                            System.out.print("X1: "+x[0]+" & "+"Y1: "+y[0]+" "+"(225 if white): "+black[0]+"\t");
                            System.out.println("X2: "+x[1]+" & "+"Y2: "+y[1]+" "+"(225 if white): "+black[1]);
                            counter();
                        }
                }
                @Override   public void mousePressed(MouseEvent e) {}
                @Override   public void mouseReleased(MouseEvent e) {}
                @Override   public void mouseEntered(MouseEvent e) {}
                @Override   public void mouseExited(MouseEvent e) {}
            });
    }
    
    //--------------------------------------------DDA block
    private void counter() {
        int dark;
        if(flag!=1) return;//-------------------to only go to counter method after it takes that 2nd click
        int dx = (x[1] - x[0]);
        int dy = (y[1] - y[0]);//---------makes it applicable for both inclinations (we do not have math.abs implies-> -ve goes as -ve)
        step = Math.abs(dx) > Math.abs(dy) ? Math.abs(dx) : Math.abs(dy);
        System.out.println("Steps: "+step);
        float Xinc = dx / (float) step;//----slope change with respect to x axis
        float Yinc = dy / (float) step;//----slope change with respect to y axis
        
        tog= new int[step][3];
        tog[0][0]=x[0]; tog[0][1]=y[0];
        tog[0][2]= (black[0]!=0) ? 1 : 0;//------------Tertiary operator where condition is true, then while is true
        //---------------------------------------------------------------send value of x1 and y1 to listOfCoordinates
        float xt=x[0],yt=y[0];  int i=0, j=1;
        //-------------to get all the coordinates between the 2 points1111
        System.out.println(tog[0][0]+" "+tog[0][1]+" "+tog[0][2]);
        while (j<step){
            if(i==2) i=0;
            xt += Xinc;
            yt += Yinc;
            tog[j][i] = (int)xt;
            tog[j][i+1] = (int)yt;
            j++;
        }
        for (i = 0; i < step; i++) {
            for (j = 0; j<= 1; j++) {
                System.out.print(tog[i][j]+" ");
            }//****************issue zone here till...

            clr = blackWhite.getRGB(tog[i][j-1], tog[i][j]);
            dark = clr & 0x000000ff;//----for blue but if it is 255, its white
            System.out.print(dark);
            tog[i][2]= (dark!=0) ? 1 : 0;
            //System.out.print(tog[i][2]);
            System.out.println();
        }
        //********issue zone till here..
    }
    //------------image size and such stuff. don't touch it
    @Override
    public Dimension getPreferredSize() {
        Dimension size = super.getPreferredSize();
        if (master != null) {
            size = new Dimension(master.getWidth(), master.getHeight());
        }
        return size;
    }
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        if (master != null) {
            int x = (getWidth() - (master.getWidth())) / 2;
            int y = (getHeight() - master.getHeight()) / 2;
            g.drawImage(blackWhite, x, y, this);
        }
    }
}

这是所有功能良好且功能齐全的代码。希望它足够好，能有所帮助。

如果它给出 255，则该像素为白色，如果为黑色，则为 0，如果您查看已经替换为 1 和 0 的部分，那么它是白色的 1。它应该给出像素的值，但它给出了所有的白色，这就是问题所在。 x1 y1 和 x2 y2 是第一次和第二次点击的坐标。您作为输出得到的列表是这些点及其颜色之间的像素坐标列表（白色的 1 和黑色的 0）

Answer 1

显然，问题在于循环而不是：

for (i = 0; i < step; i++) {
    for (j = 0; j<= 1; j++) {
        System.out.print(tog[i][j]+" ");
    }
}

我应该只使用一个循环并在循环开始时再次重置 y 坐标的值，如下所示：

for (i = 1; i < step; i++) {
   j=0;
   clr = blackWhite.getRGB(tog[i][j], tog[i][j+1]);
   System.out.print(tog[i][j]+" "+tog[i][j+1]+" ");
}

按预期工作。