我从相机捕捉图像。拍摄时捕获的图像尺寸显示得太小。但后来如果我在图库中检查，捕获的图像大小以MB显示。
我尝试调试代码，所以在调试时我在捕获图像后检查了文件的长度，长度显示26956字节，当我在库中检查相同图像时，图像的大小为1.3 MB。
为什么拍摄时图像尺寸会减少？
private void cameraIntent() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CAMERA);
}
private void onCaptureImageResult(Intent data) {
Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
(thumbnail.getWidth()/2),(int)(thumbnail.getHeight()/2),true);
thumbnail.compress(Bitmap.CompressFormat.PNG, 100, bytes);
File destination = new File(Environment.getExternalStorageDirectory(),
System.currentTimeMillis() + ".png");
FileOutputStream fo;
try {
destination.createNewFile();
fo = new FileOutputStream(destination);
fo.write(bytes.toByteArray());
fo.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
long size = destination.length();// here size of the image is too small
selectFile = false;
loadImageFromFile(destination.getAbsolutePath());
}
public void loadImageFromFile(String imageFile) {
try {
ExifInterface ei = new ExifInterface(imageFile);
int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_UNDEFINED);
Bitmap bitmap = BitmapFactory.decodeFile(imageFile);
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:
rotatedBitmap = bitmap;
break;
default:
rotatedBitmap = bitmap;
break;
}
if (rotatedBitmap != null) {
if (selectFile && fileSizeInKB > 500) {
rotatedBitmap = Bitmap.createScaledBitmap(rotatedBitmap, (int) (rotatedBitmap.getWidth() * 0.3), (int) (rotatedBitmap.getHeight() * 0.3), true);
}
else if(selectFile && fileSizeInKB > 1024){
rotatedBitmap = Bitmap.createScaledBitmap(rotatedBitmap, (int) (rotatedBitmap.getWidth() * 0.2), (int) (rotatedBitmap.getHeight() * 0.2), true);
}
else if(selectFile && fileSizeInMB > 2){
rotatedBitmap = Bitmap.createScaledBitmap(rotatedBitmap, (int) (rotatedBitmap.getWidth() * 0.1), (int) (rotatedBitmap.getHeight() * 0.1), true);
}
profileImageView.setImageBitmap(rotatedBitmap);
selectedBitmap = rotatedBitmap;
ByteArrayOutputStream stream = new ByteArrayOutputStream();
selectedBitmap.compress(Bitmap.CompressFormat.PNG, 100, stream); //replace 100 with desired quality percentage.
byte[] byteArray = stream.toByteArray();
File tempFile = File.createTempFile("temp", null, getCacheDir());
FileOutputStream fos = new FileOutputStream(tempFile);
fos.write(byteArray);
Long size = tempFile.length();
profileImage = tempFile;
}
} catch (IOException ex) {
}
}
我正在缩放从图库中选择的图像，我也想缩放从相机中捕获的图像，但是图像的大小我不合适。
有人可以帮忙吗？谢谢......
编辑：
private void cameraIntent() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (intent.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
try {
photoFile = createImageFile();
} catch (IOException ex) {
}
// Continue only if the File was successfully created
if (photoFile != null) {
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
startActivityForResult(intent, REQUEST_CAMERA);
}
}
}
private File createImageFile() throws IOException {
// Create an image file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "image";
File storageDir = Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(
imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */
);
// Save a file: path for use with ACTION_VIEW intents
fileName = image.getAbsolutePath();
return image;
}
private void onCaptureImageResult(Uri data) {
try {
Bitmap thumbnail = MediaStore.Images.Media.getBitmap(this.getContentResolver(), data);
selectFile = false;
long fileSizeInBytes = photoFile.length();
// Convert the bytes to Kilobytes (1 KB = 1024 Bytes)
fileSizeInKB = fileSizeInBytes / 1024;
// Convert the KB to MegaBytes (1 MB = 1024 KBytes)
fileSizeInMB = fileSizeInKB / 1024;
loadImageFromFile(photoFile.getAbsolutePath());
}catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void loadImageFromFile(String imageFile) {
try {
ExifInterface ei = new ExifInterface(imageFile);
int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_UNDEFINED);
Bitmap bitmap = BitmapFactory.decodeFile(imageFile);
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:
rotatedBitmap = bitmap;
break;
default:
rotatedBitmap = bitmap;
break;
}
if (rotatedBitmap != null) {
//
if (selectFile && fileSizeInMB < 1 && fileSizeInKB > 500) {
rotatedBitmap = Bitmap.createScaledBitmap(rotatedBitmap, (int) (rotatedBitmap.getWidth() * 0.9), (int) (rotatedBitmap.getHeight() * 0.9), true);
}
else if(selectFile && fileSizeInMB < 2){
rotatedBitmap = Bitmap.createScaledBitmap(rotatedBitmap, (int) (rotatedBitmap.getWidth() * 0.3), (int) (rotatedBitmap.getHeight() * 0.3), true);
}
else if(selectFile && fileSizeInMB > 2){
rotatedBitmap = Bitmap.createScaledBitmap(rotatedBitmap, (int) (rotatedBitmap.getWidth() * 0.2), (int) (rotatedBitmap.getHeight() * 0.2), true);
}
else if(selectFile && fileSizeInMB > 3){
rotatedBitmap = Bitmap.createScaledBitmap(rotatedBitmap, (int) (rotatedBitmap.getWidth() * 0.1), (int) (rotatedBitmap.getHeight() * 0.1), true);
}
// resize(rotatedBitmap,bitmap.getWidth()/2,bitmap.getHeight()/2);
profileImageView.setImageBitmap(rotatedBitmap);
selectedBitmap = rotatedBitmap;
ByteArrayOutputStream stream = new ByteArrayOutputStream();
selectedBitmap.compress(Bitmap.CompressFormat.PNG, 100, stream); //replace 100 with desired quality percentage.
byte[] byteArray = stream.toByteArray();
File tempFile = File.createTempFile("temp", null, getCacheDir());
FileOutputStream fos = new FileOutputStream(tempFile);
fos.write(byteArray);
Long size = tempFile.length();
profileImage = tempFile;
}
} catch (IOException ex) {
// UiUtils.showAlert(getString(R.string.error),NewGroupAcvitity.this);
}
}
现在使用此代码，当我在捕获后捕获图像时，需要花费时间加载图像视图并显示空白屏幕，直到图像设置为图像视图。
答案 0 :(得分：3)
您正在使用缩略图而非实际图片。
要获取实际图像，您必须将图像文件uri作为MediaStore.EXTRA_OUTPUT
示例：
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);//photoURI - file uri where you want the image to be saved
startActivityForResult(intent, REQUEST_CAMERA);
请参阅https://developer.android.com/training/camera/photobasics.html#TaskPath以获取所需步骤和完整代码。
从文件路径
获取缩放Bitmap
int targetW = 800;
int targetH = 1000;
// Get the dimensions of the bitmap
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(imagePath, bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
int scaleFactor = Math.min(photoW / targetW, photoH / targetH);
// Decode the image file into a Bitmap
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;
Bitmap bitmap = BitmapFactory.decodeFile(imagePath, bmOptions);