I am making a camera based application, where I put a rectangular view over the camera.
When I capture an image using new Camera.PictureCallback(), I cropped that image so as it will get the part of the rectangle.
Well, its working fine.
Now I implemented View.OnTouchListener and using that I made the shape movable.
So, I need to capture the image with the final selection of the user, like where they place the rectangle. 
Bitmap imageOriginal = BitmapFactory.decodeByteArray(data, 0, data.length); // 2560×1440
float scale = 1280 / 1000;
int left = (int) (scale * (imageOriginal.getWidth() - 250) / 2);
int top = (int) (scale * (imageOriginal.getHeight() - 616) / 2);
int width = (int) (scale * 750);
int height = (int) (scale * 616);
Bitmap imageConverted = Bitmap.createBitmap(imageOriginal, left, top, width, height, null, false);
This is the method i used to crop image.The values are hard corded to find the exact position. Now i need values for that top ,bottom, height, width with the changing rectangle.
//My customView that used to draw that rectangle
public class CustomView extends View {
private Paint paint = new Paint();
public CustomView(Context context) {
super(context);
}
@Override
protected void onDraw(Canvas canvas) { // Override the onDraw() Method
super.onDraw(canvas);
paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.GREEN);
paint.setStrokeWidth(10);
//center
int x0 = canvas.getWidth()/2;
int y0 = canvas.getHeight()/2;
int dx = canvas.getHeight()/3;
int dy = canvas.getHeight()/3;
//draw guide box
canvas.drawRect(x0-dx, y0-dy, x0+dx, y0+dy, paint);
}
}
//my picture callback code
Camera.PictureCallback mPicture = new Camera.PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
// Replacing the button after a photho was taken.
// File name of the image that we just took.
fileName = "IMG_" + new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()).toString() + ".jpg";
// Creating the directory where to save the image. Sadly in older
// version of Android we can not get the Media catalog name
File mkDir = new File(sdRoot, dir);
mkDir.mkdirs();
// Main file where to save the data that we recive from the camera
File pictureFile = new File(sdRoot, dir + fileName);
// Cropping image with the corresponding co-ordinates and save in to a file
try {
Bitmap imageOriginal = BitmapFactory.decodeByteArray(data, 0, data.length); // 2560×1440
float scale = 1280 / 1000;
int left = (int) (scale * (imageOriginal.getWidth() - 250) / 2);
int top = (int) (scale * (imageOriginal.getHeight() - 616) / 2);
int width = (int) (scale * 750);
int height = (int) (scale * 616);
Bitmap imageConverted = Bitmap.createBitmap(imageOriginal, left, top, width, height, null, false);
FileOutputStream purge = new FileOutputStream(pictureFile);
imageConverted.compress(Bitmap.CompressFormat.JPEG, 100, purge);
purge.flush();
purge.close();
} catch (FileNotFoundException e) {
Log.d("DG_DEBUG", "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d("DG_DEBUG", "Error accessing file: " + e.getMessage());
}
// Adding Exif data for the orientation.
try {
ProjectManager.getInstance().settings.IMAGE_LOCATION = "/sdcard/" + dir + fileName;
exif = new ExifInterface(ProjectManager.getInstance().settings.IMAGE_LOCATION);
exif.setAttribute(ExifInterface.TAG_ORIENTATION, "" + orientation);
exif.saveAttributes();
mView.saveImage(dir + fileName);
} catch (IOException e) {
e.printStackTrace();
}
}
};
For me, I take a image then crop according to dimension of the selected area of the image..
public void onPictureTaken(byte[] data, Camera camera) {
Bitmap imageOriginal = BitmapFactory.decodeByteArray(data, 0, data.length, null);
int width = imageOriginal.getWidth();
int height = imageOriginal.getHeight(); // for width
int narrowSize = Math.min(width, height); // for height
int differ = (int) Math.abs((imageOriginal.getHeight() - imageOriginal.getWidth()) / 2.0f); // for dimension
width = (width == narrowSize) ? 0 : differ;
height = (width == 0) ? differ : 0;
Matrix rotationMatrix = new Matrix();
rotationMatrix.postRotate(90); // for orientation
Bitmap imageCropped = Bitmap.createBitmap(imageOriginal, width, height, narrowSize, narrowSize, rotationMatrix, false);
}
Your rectangle is mCustomView.getWidth()*2/3 pixels wide, and mCustomView.getHeight()*2/3 pixels high, and its left corner is at 1/6 of mCustomView.getWidth(), if I understand your post correctly.
public void onPictureTaken(byte[] data, Camera camera) {
//.../
Bitmap imageOriginal = BitmapFactory.decodeByteArray(data, 0, data.length);
int[] customViewPosition;
mCustomView.getLocationInWindow(customViewPosition);
int[] surfacePosition;
mSurfaceView.getLocationInWindow(surfacePosition);
float scale = imageOriginal.getWidth()/(float)mSurfaceView.getWidth();
int left = (int) scale*(customViewPosition[0] + mCustomView.getWidth()/6F - surfacePosition[0]);
int top = (int) scale*(customViewPosition[1] + mCustomView.getHeight()/6F - surfacePosition[1]);
int width = (int) scale*mCustomView.getWidth()*2/3;
int height = (int) scale*mCustomView.getHeight()*2/3;
Bitmap imageCropped = Bitmap.createBitmap(imageOriginal, left, top, width, height, null, false);
//.../
}
来源:https://stackoverflow.com/questions/48642695/capture-image-using-dynamic-co-ordinates-through-the-camera