在调用系统相机，拍照并保存在sdcard上后，有些图片是旋转过的，如何将他们再转回来了，我做了如下操作：
1.首先看图片的属性到底是旋转了多少度
/**
* 读取图片属性：旋转的角度
*
* @param path
*图片绝对路径
* @return degree旋转的角度
*/
public static int readPictureDegree(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();
}
System.out.println("图片旋转了：" + degree + " 度");
return degree;
}2.其次读取sdcard上的图片文件，然后动态设置缩放比例，再将旋转了的图片再转回来，最后输出图片覆盖原来的图片
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
// 为true的情况下decodeFile并不分配空间，但可计算出原始图片的长度和宽度
// 获取这个图片的宽和高
bitmap = BitmapFactory.decodeFile(imagePath, options);
// 此时返回bm为空
options.inSampleSize = calculateInSampleSize(options, 150, 150);
// 重新读入图片，注意这次要把options.inJustDecodeBounds 设为 false
options.inJustDecodeBounds = false;
bitmap = BitmapFactory.decodeFile(imagePath, options);
//如果图片旋转了，就给他转回来
if(degree!=0){
bitmap = UtilTool.rotaingImageView(degree,bitmap);
}
FileOutputStream out;
try {
out = new FileOutputStream(new File(Constant.SDCARD_ROOT_PATH
+ Constant.SAVE_PATH_IN_SDCARD + IMAGE_CAPTURE_NAME));
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
} catch (FileNotFoundException e) {
e.printStackTrace();
}动态设置缩放比例
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 ? widthRatio : heightRatio;
}
return inSampleSize;
}图片旋转
public static Bitmap rotaingImageView(int angle, Bitmap bitmap) {
// 旋转图片 动作
Matrix matrix = new Matrix();
matrix.postRotate(angle);
// 创建新的图片
Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0,
bitmap.getWidth(), bitmap.getHeight(), matrix, true);
return resizedBitmap;
}【android|处理相机拍照后Bitmap和图片旋转问题】
