如何在Java中显示像素值数组中的图像？

Question

我打算在窗口内显示28x28像素的图像。像素的值为“
0”，因此我希望它显示一个带有28x28黑色正方形的窗口。但是没有图像显示。也许数组的数据（我不确定像素值是否必须为0到255之间的整数）必须是其他数据才能显示图像。谢谢！

公共课程ASD {

public static Image getImageFromArray(int[] pixels, int width, int height) {
    BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
    WritableRaster raster = (WritableRaster) image.getData();
    System.out.println(pixels.length + " " + width + " " + height);
    raster.setPixels(0,0,width,height,pixels);
    return image;
}

public static void main(String[] args) throws IOException {
    JFrame jf = new JFrame();
    JLabel jl = new JLabel();

    int[] arrayimage = new int[784];
    for (int i = 0; i < 28; i++)
    {   for (int j = 0; j < 28; j++)
            arrayimage[i*28+j] = 0;
    }
    ImageIcon ii = new ImageIcon(getImageFromArray(arrayimage,28,28));
    jl.setIcon(ii);
    jf.add(jl);
    jf.pack();
    jf.setVisible(true);
}

Answer 1

image.getData()返回栅格的 副本 。也许如果image.setData(raster)在修改栅格后调用，您将看到结果。

同样，应该给setPixels一个足够大的数组，以填充栅格的所有波段（A，R，G，B）。在将像素大小增加为28 * 28 * 4之前，我已经获得了数组索引超出范围的异常。

对于TYPE_INT_RGB，以下内容应产生白色图像：

public class ASD
{
  public static Image getImageFromArray(int[] pixels, int width, int height)
  {
    BufferedImage image =
        new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    WritableRaster raster = (WritableRaster) image.getData();
    raster.setPixels(0, 0, width, height, pixels);
    image.setData(raster);
    return image;
  }

  public static void main(String[] args) throws IOException
  {
    JFrame jf = new JFrame();
    JLabel jl = new JLabel();

    //3 bands in TYPE_INT_RGB
    int NUM_BANDS = 3;
    int[] arrayimage = new int[28 * 28 * NUM_BANDS];

    for (int i = 0; i < 28; i++)
    {
      for (int j = 0; j < 28; j++) {
        for (int band = 0; band < NUM_BANDS; band++)
          arrayimage[((i * 28) + j)*NUM_BANDS + band] = 255;
      }
    }
    ImageIcon ii = new ImageIcon(getImageFromArray(arrayimage, 28, 28));
    jl.setIcon(ii);
    jf.add(jl);
    jf.pack();
    jf.setVisible(true);
  }
}