Question

当我在android中制作照片时，我从相机收到一个字节数组。我想将此array（image）转换为2种颜色-白色和黑色。有任何想法吗？将相机模式更改为单/负不是我的解决方案。

问候。

EDIT1：代码在Java中

Answer 1

首先，您需要从数组中创建位图：

BitmapFactory.Options options = new BitmapFactory.Options();
options.inMutable = true;
// data is your byte array
Bitmap bmpOriginal = BitmapFactory.decodeByteArray(data, 0, data.length, options); 
Canvas canvas = new Canvas(bmpOriginal);
Bitmap bmpGrayscale = toGrayscale(bmpOriginal);
bmpOriginal.recycle(); // free memory immediately, as your bitmap is not garbage collected by now.

然后，您可以将彩色图像bmpOriginal传递给转换方法

public Bitmap toGrayscale(Bitmap bmpOriginal) {        
    int width, height;
    height = bmpOriginal.getHeight();
    width = bmpOriginal.getWidth();    

    Bitmap bmpGrayscale = Bitmap.createBitmap(width, height,    Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(bmpGrayscale);
    Paint paint = new Paint();
    ColorMatrix cm = new ColorMatrix();
    cm.setSaturation(0);
    ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
    paint.setColorFilter(f);
    c.drawBitmap(bmpOriginal, 0, 0, paint);
    return bmpGrayscale;
}

以上代码将为您提供灰度位图。它只是将零饱和度滤镜应用于图像。由于饱和度是颜色的纯度，因此纯度越低-色差就越小。应用上述滤镜后，您获得的唯一区别就是亮度。最亮的是白色，最暗的是黑色。如果要将其转换回字节数组，可以尝试如下操作：

Bitmap bmpGrayscale = intent.getExtras().get("data");
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bmpGrayscale.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
bmpGrayscale.recycle(); // free memory immediately, as your bitmap is not garbage collected by now.

字节数组转换为灰度。 Android拍照

1 个答案: