/**
     * 根據給定的寬和高進行拉伸
     *
     * @param origin    原圖
     * @param newWidth  新圖的寬
     * @param newHeight 新圖的高
     * @return new Bitmap
     */
    private Bitmap scaleBitmap(Bitmap origin, int newWidth, int newHeight) {
        if (origin == null) {
            return null;
        }
        int
 
 height = origin.getHeight();
        int width = origin.getWidth();
        float scaleWidth = ((float) newWidth) / width;
        float scaleHeight = ((float) newHeight) / height;
        Matrix matrix = new Matrix();
        matrix.postScale(scaleWidth, scaleHeight);// 使用後乘
        Bitmap newBM = Bitmap.createBitmap(origin, 0, 0, width, height, matrix, false
 
);
        if (!origin.isRecycled()) {
            origin.recycle();
        }
        return newBM;
    }

    /**
     * 按比例縮放圖片
     *
     * @param origin 原圖
     * @param ratio  比例
     * @return 新的bitmap
     */
    private Bitmap scaleBitmap(Bitmap origin, float ratio) {
        if (origin == null
 
) {
            return null;
        }
        int width = origin.getWidth();
        int height = origin.getHeight();
        Matrix matrix = new Matrix();
        matrix.preScale(ratio, ratio);
        Bitmap newBM = Bitmap.createBitmap(origin, 0, 0, width, height, matrix, false);
        if (newBM.equals(origin)) {
            return newBM;
        }
        origin.recycle();
        return newBM;
    }

    /**
     * 裁剪
     *
     * @param bitmap 原圖
     * @return 裁剪後的影象
     */
    private Bitmap cropBitmap(Bitmap bitmap) {
        int w = bitmap.getWidth(); // 得到圖片的寬，高
        int h = bitmap.getHeight();
        int cropWidth = w >= h ? h : w;// 裁切後所取的正方形區域邊長
        cropWidth /= 2;
        int cropHeight = (int) (cropWidth / 1.2);
        return Bitmap.createBitmap(bitmap, w / 3, 0, cropWidth, cropHeight, null, false);
    }

    /**
     * 選擇變換
     *
     * @param origin 原圖
     * @param alpha  旋轉角度，可正可負
     * @return 旋轉後的圖片
     */
    private Bitmap rotateBitmap(Bitmap origin, float alpha) {
        if (origin == null) {
            return null;
        }
        int width = origin.getWidth();
        int height = origin.getHeight();
        Matrix matrix = new Matrix();
        matrix.setRotate(alpha);
        // 圍繞原地進行旋轉
        Bitmap newBM = Bitmap.createBitmap(origin, 0, 0, width, height, matrix, false);
        if (newBM.equals(origin)) {
            return newBM;
        }
        origin.recycle();
        return newBM;
    }

    /**
     * 偏移效果
     * @param origin 原圖
     * @return 偏移後的bitmap
     */
    private Bitmap skewBitmap(Bitmap origin) {
        if (origin == null) {
            return null;
        }
        int width = origin.getWidth();
        int height = origin.getHeight();
        Matrix matrix = new Matrix();
        matrix.postSkew(-0.6f, -0.3f);
        Bitmap newBM = Bitmap.createBitmap(origin, 0, 0, width, height, matrix, false);
        if (newBM.equals(origin)) {
            return newBM;
        }
        origin.recycle();
        return newBM;
    }