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 );
下面的代码与我一起工作，它从fileUri获得位图，并在需要时进行旋转固定:
private fun getCapturedImage(selectedPhotoUri: Uri): Bitmap {
val bitmap = when {
Build.VERSION.SDK_INT < 28 -> MediaStore.Images.Media.getBitmap(
this.contentResolver,
selectedPhotoUri
)
else -> {
val source = ImageDecoder.createSource(this.contentResolver, selectedPhotoUri)
ImageDecoder.decodeBitmap(source)
}
}
// If the image is rotated, fix it
return when (ExifInterface(contentResolver.run { openInputStream(selectedPhotoUri) }).getAttributeInt(
ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_UNDEFINED)) {
ExifInterface.ORIENTATION_ROTATE_90 ->
Bitmap.createBitmap(bitmap, 0, 0, bitmap.width, bitmap.height, Matrix().apply {
postRotate(90F) }, true)
ExifInterface.ORIENTATION_ROTATE_180 ->
Bitmap.createBitmap(bitmap, 0, 0, bitmap.width, bitmap.height, Matrix().apply {
postRotate(180F) }, true)
ExifInterface.ORIENTATION_ROTATE_270 ->
Bitmap.createBitmap(bitmap, 0, 0, bitmap.width, bitmap.height, Matrix().apply {
postRotate(270F) }, true)
else -> 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;
}
大多数手机摄像头都是横拍的，也就是说如果你用竖拍，拍出来的照片会旋转90度。在这种情况下，相机软件应该填充Exif数据，以显示照片的方向。
请注意，下面的解决方案取决于填充Exif数据的相机软件/设备制造商，因此它在大多数情况下都可以工作，但它不是100%可靠的解决方案。
ExifInterface ei = new ExifInterface(photoPath);
int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_UNDEFINED);
Bitmap rotatedBitmap = null;
switch(orientation) {
case ExifInterface.ORIENTATION_ROTATE_90:
rotatedBitmap = rotateImage(bitmap, 90);
break;
case ExifInterface.ORIENTATION_ROTATE_180:
rotatedBitmap = rotateImage(bitmap, 180);
break;
case ExifInterface.ORIENTATION_ROTATE_270:
rotatedBitmap = rotateImage(bitmap, 270);
break;
case ExifInterface.ORIENTATION_NORMAL:
default:
rotatedBitmap = bitmap;
}
下面是rotateImage方法:
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);
}
