android中图片压缩以及图片旋转的方法

/**
* 计算图片的缩放值
*
* @param options
* @param reqWidth
* @param reqHeight
* @return
*/
public static int calculateInSampleSize(BitmapFactory.Options options,
int reqWidth, int reqHeight) {
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int heightRatio = Math.round((float) height
/ (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}

/**
* 根据路径获得图片并压缩返回bitmap
*
* @param filePath
* @return
*/
public static Bitmap getSmallBitmap(String filePath, int reqWidth,
int reqHeight) {
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, options);
options.inSampleSize = calculateInSampleSize(options, reqWidth,
reqHeight);
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(filePath, options);
}

/**
* 获取图片文件的信息，是否旋转了90度，如果是则反转
* @param bitmap 需要旋转的图片
* @param path   图片的路径
*/
public static Bitmap reviewPicRotate(Bitmap bitmap,String path){
int degree = getPicRotate(path);
if(degree!=0){
Matrix m = new Matrix();
int width = bitmap.getWidth();
int height = bitmap.getHeight();
m.setRotate(degree); // 旋转angle度
bitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height,m, true);// 从新生成图片
}
return bitmap;
}

/**
* 读取图片文件旋转的角度
* @param path 图片绝对路径
* @return 图片旋转的角度
*/
public static int getPicRotate(String path) {
int degree  = 0;
try {
ExifInterface exifInterface = new ExifInterface(path);
int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
switch (orientation) {
case ExifInterface.ORIENTATION_ROTATE_90:
degree = 90;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
degree = 180;
break;
case ExifInterface.ORIENTATION_ROTATE_270:
degree = 270;
break;
}
} catch (IOException e) {
e.printStackTrace();
}
return degree;
}