我有一个纵向模式的相机应用程序，它从前端和后端相机拍摄照片。我将图像保存在我的SD卡中并尝试找到相应的exif值，它总是给出0。但是我得到了存储在设备中的其他图像的预期exif方向值（如下载的图片）。
我该如何解决这个问题？任何人都可以帮助我吗？
以下是用于保存图片和查找方向的代码
PictureCallback myPictureCallback_JPG = new PictureCallback() {
@Override
public void onPictureTaken(byte[] arg0, Camera arg1) {
// TODO Auto-generated method stub
try {
File APP_FILE_PATH = new File(Environment.getExternalStorageDirectory()
.getPath() + "/Myapp/");
if (!APP_FILE_PATH.exists()) {
APP_FILE_PATH.mkdirs();
}
File file = new File(APP_FILE_PATH, "image.jpg");
FileOutputStream fos = new FileOutputStream(file);
fos.write(arg0);
fos.close();
imageFileUri=Uri.fromfile(file); getApplicationContext().getContentResolver().notifyChange(
imageFileUri, null);
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,
Uri.parse("file://"
+ Environment.getExternalStorageDirectory())));
ExifInterface exif = new ExifInterface(file.getAbsolutePath());
int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
} catch (Exception e) {
}
}
};
以下是surphace创建和更改功能的代码
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
List<Size> sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, width, height);
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
camera.setParameters(parameters);
camera.startPreview();
startPreview();
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
Camera.CameraInfo info=new Camera.CameraInfo();
for (int i=0; i < Camera.getNumberOfCameras(); i++) {
Camera.getCameraInfo(i, info);
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
camera=Camera.open(i);
defaultCameraId = i;
}
}
}
if (camera == null) {
camera=Camera.open();
}
try {
camera.setPreviewDisplay(surfaceHolder);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Camera.Parameters parameters = camera.getParameters();
android.hardware.Camera.CameraInfo info =
new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(defaultCameraId, info);
int rotation = this.getWindowManager().getDefaultDisplay()
.getRotation();
if (Integer.parseInt(Build.VERSION.SDK) >= 8)
{
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0; break;
case Surface.ROTATION_90:
degrees = 90; break;
case Surface.ROTATION_180:
degrees = 180; break;
case Surface.ROTATION_270:
degrees = 270; break;
}
int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360;
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}
else
{
parameters.set("orientation", "portrait");
}
camera.setParameters(parameters);
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SecurityException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null) return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
for (Size size : sizes) {
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
答案 0 :(得分：24)
我在三星设备上也面临同样的问题，后来我实施了ExifInterface并成功解决了问题。
在任何模式下，图像将被拍摄，它将始终仅以纵向模式存储，而在取景时也会以纵向模式返回。在我用来实现目标的代码下面，我在后置摄像头中实现，不确定是否来自摄像头。
Camera Intent @
Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
startActivityForResult(intent, 1212);
onActivityResult @
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 1212) {
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"+ Environment.getExternalStorageDirectory())));
Bitmap bitmap;
//bitmap=GlobalMethods.decodeSampledBitmapFromResource(_path, 80, 80);
bitmap=GlobalMethods.decodeFile(_path);
if (bitmap == null) {
imgMed.setImageBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.add_photo));
}
else {
imgMed.setImageBitmap(bitmap);
imgMed.setScaleType(ScaleType.FIT_XY);
}
}
}
decodeFile @
public static Bitmap decodeFile(String path) {
int orientation;
try {
if(path==null){
return null;
}
// decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 70;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 4;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale++;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
Bitmap bm = BitmapFactory.decodeFile(path,o2);
Bitmap bitmap = bm;
ExifInterface exif = new ExifInterface(path);
orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
Log.e("orientation",""+orientation);
Matrix m=new Matrix();
if((orientation==3)){
m.postRotate(180);
m.postScale((float)bm.getWidth(), (float)bm.getHeight());
// if(m.preRotate(90)){
Log.e("in orientation",""+orientation);
bitmap = Bitmap.createBitmap(bm, 0, 0,bm.getWidth(),bm.getHeight(), m, true);
return bitmap;
}
else if(orientation==6){
m.postRotate(90);
Log.e("in orientation",""+orientation);
bitmap = Bitmap.createBitmap(bm, 0, 0,bm.getWidth(),bm.getHeight(), m, true);
return bitmap;
}
else if(orientation==8){
m.postRotate(270);
Log.e("in orientation",""+orientation);
bitmap = Bitmap.createBitmap(bm, 0, 0,bm.getWidth(),bm.getHeight(), m, true);
return bitmap;
}
return bitmap;
}
catch (Exception e) {
}
return null;
}
答案 1 :(得分：2)
问题是您必须手动将exif信息放在onPictureTaken函数中。
保存图片（jpg）后，您必须创建一个Exif界面并自行输入参数：
....
exif = new ExifInterface(file.getAbsolutePath());
exif.setAttribute(ExifInterface.TAG_ORIENTATION, orientation_detected_by_you_application);
exif.saveAttributes();
手机中的其他图片是通过将exif信息放入所拍照片的应用程序制作的。
检测方向：
public void enableOrientationListener(){
if (mOrientationEventListener == null) {
mOrientationEventListener = new OrientationEventListener(getContext(), SensorManager.SENSOR_DELAY_NORMAL) {
@Override
public void onOrientationChanged(int orientation) {
// determine our orientation based on sensor response
int lastOrientation = mOrientation;
Display display = null;
if(parentActivity == null){
display = ((WindowManager)getContext().getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
}else{
display = parentActivity.getWindowManager().getDefaultDisplay();
}
if (display.getOrientation() == Surface.ROTATION_0) { // landscape oriented devices
if (orientation >= 315 || orientation < 45) {
if (mOrientation != ORIENTATION_LANDSCAPE_NORMAL) {
mOrientation = ORIENTATION_LANDSCAPE_NORMAL;
}
} else if (orientation < 315 && orientation >= 225) {
if (mOrientation != ORIENTATION_PORTRAIT_INVERTED) {
mOrientation = ORIENTATION_PORTRAIT_INVERTED;
}
} else if (orientation < 225 && orientation >= 135) {
if (mOrientation != ORIENTATION_LANDSCAPE_INVERTED) {
mOrientation = ORIENTATION_LANDSCAPE_INVERTED;
}
} else if (orientation <135 && orientation > 45) {
if (mOrientation != ORIENTATION_PORTRAIT_NORMAL) {
mOrientation = ORIENTATION_PORTRAIT_NORMAL;
}
}
} else { // portrait oriented devices
if (orientation >= 315 || orientation < 45) {
if (mOrientation != ORIENTATION_PORTRAIT_NORMAL) {
mOrientation = ORIENTATION_PORTRAIT_NORMAL;
}
} else if (orientation < 315 && orientation >= 225) {
if (mOrientation != ORIENTATION_LANDSCAPE_NORMAL) {
mOrientation = ORIENTATION_LANDSCAPE_NORMAL;
}
} else if (orientation < 225 && orientation >= 135) {
if (mOrientation != ORIENTATION_PORTRAIT_INVERTED) {
mOrientation = ORIENTATION_PORTRAIT_INVERTED;
}
} else if (orientation <135 && orientation > 45) {
if (mOrientation != ORIENTATION_LANDSCAPE_INVERTED) {
mOrientation = ORIENTATION_LANDSCAPE_INVERTED;
}
}
}
}
};
}
if (mOrientationEventListener.canDetectOrientation()) {
mOrientationEventListener.enable();
}
}
private static final int ORIENTATION_PORTRAIT_NORMAL = 1;
private static final int ORIENTATION_PORTRAIT_INVERTED = 2;
private static final int ORIENTATION_LANDSCAPE_NORMAL = 3;
private static final int ORIENTATION_LANDSCAPE_INVERTED = 4;
public void disableOrientationListener(){
if(mOrientationEventListener != null){
mOrientationEventListener.disable();
}
}
您应该将mOrientation设置为您图像的方向属性。
答案 2 :(得分：2)
很久以前这个问题就解决了，但是我遇到了一些使相机正常工作的困难所以这是我的最终解决方案，不使用exif。我希望这会有助于其他人：
public void startPreview() {
try {
Log.i(TAG, "starting preview: " + started);
// ....
Camera.CameraInfo camInfo = new Camera.CameraInfo();
Camera.getCameraInfo(cameraIndex, camInfo);
int cameraRotationOffset = camInfo.orientation;
// ...
Camera.Parameters parameters = camera.getParameters();
List<Camera.Size> previewSizes = parameters.getSupportedPreviewSizes();
Camera.Size previewSize = null;
float closestRatio = Float.MAX_VALUE;
int targetPreviewWidth = isLandscape() ? getWidth() : getHeight();
int targetPreviewHeight = isLandscape() ? getHeight() : getWidth();
float targetRatio = targetPreviewWidth / (float) targetPreviewHeight;
Log.v(TAG, "target size: " + targetPreviewWidth + " / " + targetPreviewHeight + " ratio:" + targetRatio);
for (Camera.Size candidateSize : previewSizes) {
float whRatio = candidateSize.width / (float) candidateSize.height;
if (previewSize == null || Math.abs(targetRatio - whRatio) < Math.abs(targetRatio - closestRatio)) {
closestRatio = whRatio;
previewSize = candidateSize;
}
}
int rotation = getWindowManager().getDefaultDisplay().getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break; // Natural orientation
case Surface.ROTATION_90:
degrees = 90;
break; // Landscape left
case Surface.ROTATION_180:
degrees = 180;
break;// Upside down
case Surface.ROTATION_270:
degrees = 270;
break;// Landscape right
}
int displayRotation;
if (isFrontFacingCam) {
displayRotation = (cameraRotationOffset + degrees) % 360;
displayRotation = (360 - displayRotation) % 360; // compensate
// the
// mirror
} else { // back-facing
displayRotation = (cameraRotationOffset - degrees + 360) % 360;
}
Log.v(TAG, "rotation cam / phone = displayRotation: " + cameraRotationOffset + " / " + degrees + " = "
+ displayRotation);
this.camera.setDisplayOrientation(displayRotation);
int rotate;
if (isFrontFacingCam) {
rotate = (360 + cameraRotationOffset + degrees) % 360;
} else {
rotate = (360 + cameraRotationOffset - degrees) % 360;
}
Log.v(TAG, "screenshot rotation: " + cameraRotationOffset + " / " + degrees + " = " + rotate);
Log.v(TAG, "preview size: " + previewSize.width + " / " + previewSize.height);
parameters.setPreviewSize(previewSize.width, previewSize.height);
parameters.setRotation(rotate);
camera.setParameters(parameters);
camera.setPreviewDisplay(mHolder);
camera.startPreview();
Log.d(TAG, "preview started");
started = true;
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
答案 3 :(得分：1)
你忽略了一个例外：
try {
// Code
int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
} catch (Exception e) {
}
尝试：
try {
// Code
int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
} catch (Exception e) {
e.printStackTrace();
}
发布logcat。抛弃异常是不明智的。