缩放矩阵变换图像以进行合成

Question

我正在设置一个相机视图，它的顶部有一个图像视图，并使用矩阵变换在屏幕上移动图像。当我拍照时，我希望能够以正确的位置和缩放比例将图像合成到照片上。照片只能是纵向照片，如果是横向照片则进行旋转。

public void onPictureTaken(byte[] data, Camera camera) {
    
    BitmapFactory.Options opt = new BitmapFactory.Options();
    this.newPhoto = BitmapFactory.decodeByteArray(data, 0, data.length, opt);
    
    int photoWidth = newPhoto.getWidth() > newPhoto.getHeight()?newPhoto.getHeight():newPhoto.getWidth();
    int photoHeight = newPhoto.getWidth() > newPhoto.getHeight()?newPhoto.getWidth():newPhoto.getHeight();

    //Preview is fullscreen
    Display display = getWindowManager().getDefaultDisplay(); 
    int previewWidth = display.getWidth();
    int previewHeight = display.getHeight();
    
    
    float scale = (float)photoHeight / (float)previewHeight;
    float scaleX = (float)photoWidth / (float)previewWidth;
    
    Bitmap finished = Bitmap.createBitmap(photoWidth, photoHeight, newPhoto.getConfig());
    
    //Create canvas and draw photo into it 
    //[snip]
    
    //Draw character onto canvas
    int imageResource = getResources().getIdentifier(character + "large", "drawable", getPackageName());
    if (imageResource != 0) {
        Bitmap character = BitmapFactory.decodeResource(this.getResources(), imageResource);
        RectF rect = new RectF();
        float[] values = new float[9];
        
        matrix.getValues(values);
        rect.left = values[Matrix.MTRANS_X] * scaleX;
        rect.top = values[Matrix.MTRANS_Y] * scale;
        //273x322 WidthxHeight of preview character image
        rect.right = rect.left + (273 * values[Matrix.MSCALE_X]) * scale;
        rect.bottom = rect.top + (322 * values[Matrix.MSCALE_Y]) * scale;
        
        //Logging here
        
        
        canvas.drawBitmap(character, null, rect, null);
        character.recycle();
    }

    
    System.gc();
    newPhoto = finished;
    showDialog(DIALOG_PHOTO_RESULT);
}

日志：

预览：480x854 照片：1536x2048

规模：2.3981264

矩阵：(112.45,375.85) 比例：(1.00,1.00)

矩形：(359.8342,901.34326) w:654.6885 h:772.1968

图像矩形似乎没有缩放足够大，因为生成的合成图像的字符离顶部/左侧太远并且太小。

Answer 1

问题是 android 正在预先缩放角色图像，这会抛出我所有的缩放计算

通过将角色图像移动到drawable-nodpi文件夹中，我能够停止 android 缩放设备的图像，以便图像可以缩放以匹配相机视图。