Android Bitmap图片压缩，图片倒影

/**
* 图片倒影
*
* @param originalBitmap 原始图片
* @return 带倒影图片
*/
public static Bitmap createReflectedImage(Bitmap originalBitmap, boolean isAppStart) {
int refectionGap;
if (isAppStart) {
refectionGap = 0;
} else {
refectionGap = 4;
}
int width = originalBitmap.getWidth();
int height = originalBitmap.getHeight();
Matrix matrix = new Matrix();
matrix.preScale(1, -1);//x轴变为原来的1倍,y轴变为原来的-1倍
Bitmap reflectionBitmap = Bitmap.createBitmap(originalBitmap, 0, height >> 1, width, height >> 1, matrix, false);
Bitmap withReflectionBitmap = Bitmap.createBitmap(width, (height + (height >> 1) + refectionGap), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(withReflectionBitmap);
//画原始图片
canvas.drawBitmap(originalBitmap, 0, 0, null);
//画间隔
Paint defaultPaint = new Paint();
canvas.drawRect(0, height, width, height + refectionGap, defaultPaint);
//画倒影
canvas.drawBitmap(reflectionBitmap, 0, height + refectionGap, null);
//实现倒影
Paint paint = new Paint();
LinearGradient shader = new LinearGradient(0, originalBitmap.getHeight(), 0, withReflectionBitmap.getHeight() + 4, 0x70ffffff, 0x00ffffff, Shader.TileMode.MIRROR);
paint.setShader(shader);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
canvas.drawRect(0, height, width, withReflectionBitmap.getHeight(), paint);
reflectionBitmap.recycle();
originalBitmap.recycle();
return withReflectionBitmap;
}

/**
* 获取压缩比率
*
* @param options
* @param reqWidth  目标宽度
* @param reqHeight 目标高度
* @return 压缩比率
*/
private static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
int height = options.outHeight;
int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
int heightRatio = Math.round((float) height / (float) reqHeight);
int widthRatio = Math.round((float) width / (float) reqWidth);
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}

/**
* 对图片进行压缩
*
* @param mResources Resources
* @param imageId    图片资源ID
* @param reqWidth   目标宽度
* @param reqHeight  目标高度
* @return bitmap
*/
public static Bitmap decodeSampleBitmapFromResource(Resources mResources, int imageId, int reqWidth, int reqHeight) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(mResources, imageId, options);
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
options.inJustDecodeBounds = false;
return BitmapFactory.decodeResource(mResources, imageId, options);
}