将2D二进制矩阵在Java黑/白图像 [英] Convert 2D binary matrix to black/white image in java

问题描述

我是新的Java。我只用1和0，现在2D二进制矩阵。我想将其保存为JPG格式（黑色和白色）与相同的宽度和高度。我怎么能知道呢？我试过code以下，但失败了，说：java.lang.IllegalArgumentException异常：图像== NULL请帮我与，或给我你的更好的解决方案。非常感谢你。

 公共静态无效的主要（字串[] args）抛出IOException    //结果是双[25] [33]只用1和0的二进制矩阵;
    INT高度= result.length;
    INT宽度=结果[0]。长度;;
    字节[]数据=新的字节[高*宽]
    INT K = 0;
    的for（int i = 0; I＆LT;高度;我++）{
        对于（INT J = 0; J＆LT;宽度; J ++）{
            数据[K] =（字节）结果[I] [J]。
            ķ++;
        }
        System.out.print（\\ n）;
    }
    输入的InputStream =新ByteArrayInputStream的（数据）;
    BufferedImage的输出= ImageIO.read（输入）;
    ImageIO.write（输出中，JPG，新的文件（C：/result.jpg））;}
 

解决方案

这是创建一个30×30方格盒一个简单的例子：

 公共静态无效的主要（字符串参数... args）抛出IOException
    INT W = 30，H = 30;    //创建的二进制映射
    字节BLACK =（字节）0，白色=（字节）255;
    字节[] =地图{黑，白};
    IndexColorModel的ICM =新IndexColorModel的（1，map.length，地图，地图，地图）;    //创建格仔数据
    INT []数据=新的INT [W * H]。
    的for（int i = 0; I＆LT;瓦;我++）
        对于（INT J = 0; J＆LT; 1H; J ++）
            数据[I * H + J] =则i％4 2＆放大器;＆放大器; Ĵ％4 2 ||则i％4是H. = 2和;＆放大器; Ĵ％4是H. = 2？黑，白;    //创建颜色模型和数据图像
    的WritableRaster光栅= icm.createCompatibleWritableRaster（W，H）;
    raster.setPixels（0，0，W，H，数据）;
    BufferedImage的双向=新的BufferedImage（ICM，光栅，假，空）;    //输出到文件
    ImageIO.write（BI，JPG，新的文件（C：\\\\ \\\\用户\\\\用户\\\\桌面test.jpg放在））;
}
 

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编辑：

有关你在做什么，你其实并不需要创建自己的ImageColorModel，您可以使用内置的类型：BufferedImage.TYPE_BYTE_GRAY或TYPE_BYTE_BINARY。以下是一个更好的例子，并展示了如何使用灰度来获得一个方格框：

 公共静态无效的主要（字符串参数... args）抛出IOException
    INT W = 40，H = 40的div = 5;    BufferedImage的双向=新的BufferedImage（W，H，BufferedImage.TYPE_BYTE_GRAY）;
    的WritableRaster光栅= bi.getRaster（）;    的for（int i = 0; I＆LT;瓦;我++）
        对于（INT J = 0; J＆LT; 1H; J ++）
            raster.setSample（I，J，0.128 +（INT）（127 * Math.sin（Math.PI * I / W *的div）* Math.sin（Math.PI *焦耳/ H *的div）））;    ImageIO.write（BI，JPG，新的文件（C：\\\\ \\\\用户\\\\用户\\\\桌面test.jpg放在））;
}
 

I am new for java. I have 2D binary matrix with only 1s and 0s now. I want to save it as jpg image(black and white) with same width and height. How could I realize that? I tried the code below but failed, saying "java.lang.IllegalArgumentException: image == null!" Please help me with that or give me your better solution. Thank you very much.

public static void main(String[] args) throws IOException {

    //result is double[25][33] binary matrix with only 1s and 0s;
    int height=result.length;
    int width=result[0].length;;
    byte[] data = new byte[height*width];
    int k=0;
    for(int i = 0;i < height;i++){
        for(int j = 0; j < width; j++){
            data[k]=(byte)result[i][j];
            k++;
        }
        System.out.print("\n");
    }
    InputStream input = new ByteArrayInputStream(data);
    BufferedImage output = ImageIO.read(input);
    ImageIO.write(ouput, "jpg", new File("c:/result.jpg"));

}

解决方案

This is a simple example that creates a 30x30 checkered box:

public static void main(String... args) throws IOException {
    int w = 30, h = 30;

    // create the binary mapping
    byte BLACK = (byte)0, WHITE = (byte)255;
    byte[] map = {BLACK, WHITE};
    IndexColorModel icm = new IndexColorModel(1, map.length, map, map, map);

    // create checkered data
    int[] data = new int[w*h];
    for(int i=0; i<w; i++)
        for(int j=0; j<h; j++)
            data[i*h + j] = i%4<2 && j%4<2 || i%4>=2 && j%4>=2 ? BLACK:WHITE;

    // create image from color model and data
    WritableRaster raster = icm.createCompatibleWritableRaster(w, h);
    raster.setPixels(0, 0, w, h, data);
    BufferedImage bi = new BufferedImage(icm, raster, false, null);

    // output to a file
    ImageIO.write(bi, "jpg", new File("C:\\Users\\user\\Desktop\\test.jpg"));
}

---

EDIT:

For what you are doing you actually don't need to create your own ImageColorModel, you can use a built in type: BufferedImage.TYPE_BYTE_GRAY or TYPE_BYTE_BINARY. Here is a better example and shows how to use grayscale to get a checkered box:

public static void main(String... args) throws IOException {
    int w = 40, h = 40, divs = 5;

    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY);
    WritableRaster raster = bi.getRaster();

    for(int i=0; i<w; i++)
        for(int j=0; j<h; j++)
            raster.setSample(i,j,0,128+(int)(127*Math.sin(Math.PI*i/w*divs)*Math.sin(Math.PI*j/h*divs)));

    ImageIO.write(bi, "jpg", new File("C:\\Users\\user\\Desktop\\test.jpg"));
}

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