Question

我正在创建一个代码桶阅读器，我已经拍摄了RGB图片并使用onPictureTaken（byte [] _data，Camera _camera）将其存储在一个数组中，现在我需要将其转换为二进制矩阵（灰度）这就是我到目前为止所做的事情

public class cam extends Activity implements Callback {
Camera camera = null;
@SuppressWarnings("deprecation")
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    SurfaceView view = new SurfaceView(this);
    view.getHolder().addCallback(this);
    view.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    setContentView(view);
}




@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    Camera.Parameters parameters = camera.getParameters();
    parameters.setPreviewSize(width, height);
    parameters.getSupportedPictureFormats();
     List<Integer> formats = parameters.getSupportedPictureFormats();
        if (formats.contains(PixelFormat.RGB_888))
            parameters.setPictureFormat(PixelFormat.RGB_888);
    camera.setParameters(parameters);
    camera.startPreview();  

}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    try {
        camera = Camera.open();
        camera.setPreviewDisplay(holder);
    } catch (Exception e) {
        e.printStackTrace();
    }       
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    camera.stopPreview();
    camera.release();
    camera = null;
}

@SuppressLint("ShowToast")
@Override
public boolean onTouchEvent(MotionEvent event) {
    switch(event.getAction()){
    case MotionEvent.ACTION_DOWN:

        PictureCallback jpegCallback = new PictureCallback() {
            public void onPictureTaken(byte[] _data, Camera _camera) {                  
                try {
                    File fs = new File(cam.this.getFilesDir()+"/image.jpeg");                                               
                    FileOutputStream fos = new FileOutputStream(fs);
                    fos.write(_data);
                    fos.flush();
                    fos.close();
                    Toast.makeText(cam.this,fs.getAbsolutePath(),0).show();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                camera.startPreview();

            }
        };
        camera.takePicture(null, null, jpegCallback);           
        break;
    }
    return super.onTouchEvent(event);
}

}

Answer 1

从中取出Bitmap，然后执行

private byte[] convertToGray(Bitmap bmp) {
    int width = bmp.getWidth();
    int height = bmp.getHeight();
    byte[] grayscale = new byte[width*height];
    int val, R, G, B;
    for (int i = 0; i < height; i++) {
        for (int j = 0; j < width; j++) {
            val = bmp.getPixel(j, i);
            R = (val >> 16) & 0xff ;     
            G = (val >> 8) & 0xff ; 
            B = val & 0xff ;
            grayscale[i*width + j] = (byte)(0.21*R + 0.71*G + 0.07*B);
        }
    }

    return grayscale;

干杯！

在Android中使用数组矩阵RGB将图像转换为灰度

1 个答案: