我正在捕捉图像并将其设置为图像视图。
public void captureImage() {
Intent intentCamera = new Intent("android.media.action.IMAGE_CAPTURE");
File filePhoto = new File(Environment.getExternalStorageDirectory(), "Pic.jpg");
imageUri = Uri.fromFile(filePhoto);
MyApplicationGlobal.imageUri = imageUri.getPath();
intentCamera.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(intentCamera, TAKE_PICTURE);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intentFromCamera) {
super.onActivityResult(requestCode, resultCode, intentFromCamera);
if (resultCode == RESULT_OK && requestCode == TAKE_PICTURE) {
if (intentFromCamera != null) {
Bundle extras = intentFromCamera.getExtras();
if (extras.containsKey("data")) {
bitmap = (Bitmap) extras.get("data");
}
else {
bitmap = getBitmapFromUri();
}
}
else {
bitmap = getBitmapFromUri();
}
// imageView.setImageBitmap(bitmap);
imageView.setImageURI(imageUri);
}
else {
}
}
public Bitmap getBitmapFromUri() {
getContentResolver().notifyChange(imageUri, null);
ContentResolver cr = getContentResolver();
Bitmap bitmap;
try {
bitmap = android.provider.MediaStore.Images.Media.getBitmap(cr, imageUri);
return bitmap;
}
catch (Exception e) {
e.printStackTrace();
return null;
}
}
但问题是，某些设备上的图像每次旋转时。例如，在三星设备上，它工作得很好，但在索尼Xperia上，图像旋转了90度，在东芝Thrive(平板电脑)上旋转了180度。
这里的解决方案基于上面的解决方案，但只需要上下文和图像文件作为输入
public static Bitmap rectifyImage(Context context,File imageFile){
Bitmap originalBitmap= BitmapFactory.decodeFile(imageFile.getAbsolutePath());
try{
Uri uri=Uri.fromFile(imageFile);
InputStream input = context.getContentResolver().openInputStream(uri);
ExifInterface ei;
if (Build.VERSION.SDK_INT > 23)
ei = new ExifInterface(input);
else
ei = new ExifInterface(uri.getPath());
int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
switch (orientation) {
case ExifInterface.ORIENTATION_ROTATE_90:
return rotateImage(originalBitmap, 90);
case ExifInterface.ORIENTATION_ROTATE_180:
return rotateImage(originalBitmap, 180);
case ExifInterface.ORIENTATION_ROTATE_270:
return rotateImage(originalBitmap, 270);
default:
return originalBitmap;
}
}catch (Exception e){
return originalBitmap;
}
}
public static Bitmap rotateImage(Bitmap source, float angle) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
return Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(),
matrix, true);
}
可悲的是，上面的@jason-robinson回答对我没用。
虽然旋转函数工作得很完美:
public static Bitmap rotateImage(Bitmap source, float angle) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
return Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(), matrix,
true);
}
我必须做以下事情来获得方向，因为Exif方向总是0
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode,resultCode,data);
if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && data != null) {
Uri selectedImage = data.getData();
String[] orientationColumn = {MediaStore.Images.Media.ORIENTATION};
Cursor cur = managedQuery(imageUri, orientationColumn, null, null, null);
int orientation = -1;
if (cur != null && cur.moveToFirst()) {
orientation = cur.getInt(cur.getColumnIndex(orientationColumn[0]));
}
InputStream imageStream = getContentResolver().openInputStream(selectedImage);
Bitmap bitmap = BitmapFactory.decodeStream(imageStream);
switch(orientation) {
case 90:
bitmap = rotateImage(chosen_image_bitmap, 90);
break;
case 180:
bitmap = rotateImage(chosen_image_bitmap, 180);
break;
case 270:
bitmap = rotateImage(chosen_image_bitmap, 270);
break;
default:
break;
}
imageView.setImageBitmap(bitmap );
这是Xamarin。Android版本:
来自@Jason Robinson的回答:
Bitmap rotate(Bitmap bitmap, int angle)
{
var matrix = new Matrix();
matrix.PostRotate(angle);
return Bitmap.CreateBitmap(bitmap, 0, 0, bitmap.Width, bitmap.Height, matrix, true);
}
Bitmap rotateIfRequired(Bitmap bitmap, string imagePath)
{
var ei = new ExifInterface(imagePath);
var orientation = ei.GetAttributeInt(ExifInterface.TagOrientation, (int)Android.Media.Orientation.Undefined);
switch (orientation)
{
case (int)Android.Media.Orientation.Rotate90: return rotate(bitmap, 90);
case (int)Android.Media.Orientation.Rotate180: return rotate(bitmap, 180);
case (int)Android.Media.Orientation.Rotate270: return rotate(bitmap, 270);
default: return bitmap;
}
}
然后calculateInSampleSize方法:
int calculateInSampleSize(BitmapFactory.Options options, int reqW, int reqH)
{
float h = options.OutHeight;
float w = options.OutWidth;
var inSampleSize = 1;
if (h > reqH || w > reqW)
{
if (reqH == 0) inSampleSize = (int)Math.Floor(w / reqW);
else if (reqW == 0) inSampleSize = (int)Math.Floor(h / reqH);
else
{
var hRatio = (int)Math.Floor(h / reqH);
var wRatio = (int)Math.Floor(w / reqW);
inSampleSize = false ? Math.Max(hRatio, wRatio) : Math.Min(hRatio, wRatio);
}
}
return inSampleSize;
}
来自@Sami Eltamawy的回答:
Bitmap handleSamplingAndRotationBitmap(string imagePath)
{
var maxHeight = 1024;
var maxWidth = 1024;
var options = new BitmapFactory.Options();
options.InJustDecodeBounds = true;
BitmapFactory.DecodeFile(imagePath, options);
options.InSampleSize = calculateInSampleSize(options, maxWidth, maxHeight);
options.InJustDecodeBounds = false;
var bitmap = BitmapFactory.DecodeFile(imagePath, options);
bitmap = rotateIfRequired(bitmap, imagePath);
return bitmap;
}
Jason Robinson和Sami Eltamawy的回答非常棒。
只是为了完成该方法的改进，您应该使用compat ExifInterface。
com.android.support: exifinterface: $ {lastLibVersion}
你将能够实例化ExifInterface(pior API <24)与InputStream(从ContentResolver)而不是uri路径避免“文件未找到异常”
https://android-developers.googleblog.com/2016/12/introducing-the-exifinterface-support-library.html
在没有使用ExifInterface的情况下得到了这个问题的答案。我们可以得到相机的旋转不管是前置相机还是后置相机无论你使用的是哪一个然后在创建位图时我们可以使用matrix。postrotate (degree)来旋转位图
public int getRotationDegree() {
int degree = 0;
for (int i = 0; i < Camera.getNumberOfCameras(); i++) {
Camera.CameraInfo info = new Camera.CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
degree = info.orientation;
return degree;
}
}
return degree;
}
计算旋转后，你可以像下面这样旋转你的位图:
Matrix matrix = new Matrix();
matrix.postRotate(getRotationDegree());
Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), matrix, true);
这里的bm应该是位图。
如果你想知道前置摄像头的旋转，只需更改camera . camerainfo。CAMERA_FACING_BACK to Camera.CameraInfo。CAMERA_FACING_FRONT以上。
我希望这能有所帮助。
