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基于@ben75 提出的这个问题：Android : save a Bitmap to bmp file format

我现在的问题是：如何获得每像素 1 位深度的 BMP 图像（黑白）？

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2 回答 2

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回答我自己的问题...

在整个网络上进行了一番艰难的搜索后，我意识到我必须创建两件事：一个黑白位图 - 并使用将所有 0 用于低于 128 的颜色和 255 用于其余颜色的方法来做到这一点，就像这样（这是 C# 代码，因为我使用 Xamarin 来编写我的应用程序）：

private void ConvertArgbToOneColor (Bitmap bmpOriginal, int width, int height){
        int pixel;
        int k = 0;
        int B=0,G=0,R=0;
        try{
            for(int x = 0; x < height; x++) {
                for(int y = 0; y < width; y++, k++) {
                    pixel = bmpOriginal.GetPixel(y, x);

                    R = Color.GetRedComponent(pixel);
                    G = Color.GetGreenComponent(pixel);
                    B = Color.GetBlueComponent(pixel);

                    R = G = B = (int)(0.299 * R + 0.587 * G + 0.114 * B);
                    if (R < 128) {
                        m_imageArray[k] = 0;
                    } else {
                        m_imageArray[k] = 1;
                    }
                }
                if(m_dataWidth>width){
                    for(int p=width;p<m_dataWidth;p++,k++){
                        m_imageArray[k]=1;
                    }
                }
            }
        }catch (Exception e) {
            System.Console.WriteLine ("Converting to grayscale ex: " + e.Message);
        }
    }

然后获取 Monochrome 图像的 byteArray：

int length = 0;
for (int i = 0; i < m_imageArray.Length; i = i + 8) {
    byte first = m_imageArray[i];
    for (int j = 0; j < 7; j++) {
        byte second = (byte) ((first << 1) | m_imageArray[i + j]);
        first = second;
    }
    m_rawImage[length] = first;
    length++;
}

最后使用以下变量“手动”创建位图并将它们放入 FileOutputStream 以保存文件：

    private static int FILE_HEADER_SIZE = 14;
    private static int INFO_HEADER_SIZE = 40;

    // Bitmap file header
    private byte[] bfType = { (byte) 'B', (byte) 'M' };
    private int bfSize = 0;
    private int bfReserved1 = 0;
    private int bfReserved2 = 0;
    private int bfOffBits = FILE_HEADER_SIZE + INFO_HEADER_SIZE + 8;

    // Bitmap info header
    private int biSize = INFO_HEADER_SIZE;
    private int biWidth = 0;
    private int biHeight = 0;
    private int biPlanes = 1;
    private int biBitCount = 1;
    private int biCompression = 0;
    private int biSizeImage = 0;
    private int biXPelsPerMeter = 0x0;
    private int biYPelsPerMeter = 0x0;
    private int biClrUsed = 2;
    private int biClrImportant = 2;

    // Bitmap raw data
    private byte[] bitmap;

    // Scanlinsize;
    int scanLineSize = 0;

    // Color Pallette to be used for pixels.
    private byte[] colorPalette = { 0, 0, 0, (byte) 255, (byte) 255,
        (byte) 255, (byte) 255, (byte) 255 };
于 2014-09-10T13:45:18.543 回答
0 
Bitmap bmpMonochrome = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); 
Canvas canvas = new Canvas(bmpMonochrome); 
ColorMatrix ma = new ColorMatrix(); 
ma.setSaturation(0); 
Paint paint = new Paint(); 
paint.setColorFilter(new ColorMatrixColorFilter(ma)); 
canvas.drawBitmap(bmpSrc, 0, 0, paint);

像这样！ 资源

于 2014-08-22T13:14:48.953 回答