Question

我编写了以下代码，将灰度图像的像素读取到1 d数组。运行代码时怎么会出错？

 public class LoadImage {
   BufferedImage image;
   void load()throws Exception { 
     File input = new File("lena.png");
     image = ImageIO.read(input);
   }
   public Dimension getImageSize() {
     return new Dimension(image.getWidth(), image.getHeight());
   }

   public int[] getImagePixels() {
     int [] dummy = null;
     int wid, hgt;

     // compute size of the array
     wid = image.getWidth();
     hgt = image.getHeight();

     // start getting the pixels
     Raster pixelData;
     pixelData = image.getData();
     return pixelData.getPixels(0, 0, wid, hgt, dummy);
   }
 }

主要班级

 public static void main(String[] args) throws IOException, Exception {
   LoadImage l = new LoadImage();
   l.load();
   int pixel[];
   pixel= l.getImagePixels();
 }

Answer 1

好的问题来自于传递File对象时ImageIO.read中的格式代码。试试这个：

import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.awt.image.Raster;
import java.io.IOException;
import javax.imageio.ImageIO;

public class LoadImage {
  BufferedImage image;
  void load() throws Exception { 
    image = ImageIO.read(getClass().getResourceAsStream("lena.png"));
  }

  public Dimension getImageSize() {
    return new Dimension(image.getWidth(), image.getHeight());
  }

  public int[] getImagePixels() {
    int [] dummy = null;
    int wid, hgt;

    // compute size of the array
    wid = image.getWidth();
    hgt = image.getHeight();

    // start getting the pixels
    Raster pixelData;
    pixelData = image.getData();

    System.out.println("wid:"+ wid);
    System.out.println("hgt:"+ hgt);
    System.out.println("Channels:"+pixelData.getNumDataElements());
    return pixelData.getPixels(0, 0, wid, hgt, dummy);
  }

  public static void main(String[] args) throws IOException, Exception {
    LoadImage l = new LoadImage();
    l.load();
    int[] pixel;
    pixel= l.getImagePixels();
    System.out.println("length:"+pixel.length);

    int height = 482;
    int width = 372;
    int channels = 3;
    int color = 0;

    BufferedImage red = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);
    BufferedImage green = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);
    BufferedImage blue = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR);

    for (int y = 0; y < height; y++) {
      for (int x = 0; x < width; x++) {
        blue.setRGB(x, y, pixel[color * channels]);
        green.setRGB(x, y, pixel[color * channels + 1] << 8);
        red.setRGB(x, y, pixel[color * channels + 2] << 16);
        color++;
      }
    }
    ImageIO.write(red, "png", new File("red.png"));
    ImageIO.write(green, "png", new File("green.png"));
    ImageIO.write(blue, "png", new File("blue.png"));
  }
}

当我传递一个372x482的PNG（24位（3通道）颜色）时，我得到了

wid:372
hgt:482
Channels:3
length:537912

使用更新后的代码这就是如何获取它返回的数组并将每个通道保存回文件。

将灰度图像读入1-d数组

1 个答案: