gpt4 book ai didi

java - 垂直图像旋转

转载 作者:太空宇宙 更新时间:2023-11-04 11:19:19 25 4
gpt4 key购买 nike

我正在使用以下代码在我的应用程序中拍摄并保存照片:

    public void addPhoto(){
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {}

// Continue only if the File was successfully created
if (photoFile != null) {
Uri photoURI = FileProvider.getUriForFile(this,
BuildConfig.APPLICATION_ID,
photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
}

}


@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode==REQUEST_IMAGE_CAPTURE&&resultCode==RESULT_OK){

Intent i = new Intent(Assignments.this, AddAssignment.class);
i.putExtra("fileName", mCurrentPhotoPath);
startActivity(i);
}
}

然后,我使用以下代码缩放图像以创建较小尺寸的预览:

public Bitmap getImage(){
int targetW;
int targetH;

// Get the dimensions of the bitmap
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(fileName, bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;

if(photoW>photoH){
targetW=400;
targetH=300;
}else{
targetW=300;
targetH=400;

}



// Determine how much to scale down the image
int scaleFactor = Math.min(photoW/targetW, photoH/targetH);

// Decode the image file into a Bitmap sized to fill the View
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;

Bitmap bitmap = BitmapFactory.decodeFile(fileName, bmOptions);
photo=bitmap;

return(bitmap);

}

我的问题是,如果拍摄的图像是垂直的,则图像会水平翻转。我不知道这到底发生在哪里,如果有任何帮助,我将不胜感激。谢谢。

最佳答案

某些设备相机使用 Exif 标志。这是他们以自然轮换方式存储它的地方,并用一个标志来表示它。

下面是我编写的一些用于在内存中旋转位图的代码。请酌情使用/应用。

有关 exif 标志的信息:

https://www.howtogeek.com/254830/why-your-photos-dont-always-appear-correctly-rotated/

http://sylvana.net/jpegcrop/exif_orientation.html

     public static Bitmap decodeSampledBitmapFromFile(String photoDir,
int reqWidth, int reqHeight) {

// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;

BitmapFactory.decodeFile(photoDir, options);

// Calculate inSampleSize
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
options.inPreferredConfig = Bitmap.Config.RGB_565;
int inSampleSize = 1;

if (height > reqHeight) {
inSampleSize = Math.round((float) height / (float) reqHeight);
}

int expectedWidth = width / inSampleSize;

if (expectedWidth > reqWidth) {// If bigger SampSize..
inSampleSize = Math.round((float) width / (float) reqWidth);
}


options.inSampleSize = inSampleSize;

// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;


Bitmap photo = BitmapFactory.decodeFile(photoDir, options);

// WILL CHECK ROTATION FLAGS AND ROTATE AS NECESSARY
try {
ExifInterface exif = new ExifInterface(photoDir);
float rotation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

float rotationInDegrees = exifToDegrees(rotation);

Matrix matrix = new Matrix();
matrix.postRotate(rotationInDegrees);

// if needs rotating, rotate in memory.
if(rotationInDegrees != 0)
photo = Bitmap.createBitmap(photo, 0, 0, photo.getWidth(), photo.getHeight(), matrix, true);

} catch (OutOfMemoryError e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}

return photo;
}

辅助方法:

private static float exifToDegrees(float exifOrientation) {
// MAY NEED TO HANDLE THE OTHER FLAGS TOO, though I don't think android flips photos.
if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_90) {
return 90;
} else if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_180) {
return 180;
} else if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_270) {
return 270;
}
return 0;
}

关于java - 垂直图像旋转,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/45107077/

25 4 0
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com