Get angle of view of android camera device
Solution 1
I search the google a person show possibility which he calculate FOV by Camera2 api
https://photo.stackexchange.com/questions/54054/calculating-the-field-of-view-for-a-nexus-5
and found the equation
http://www.bobatkins.com/photography/technical/field_of_view.html
FOV (rectilinear) = 2 * arctan (frame size/(focal length * 2))
thus, we need to know frame size and focal length
the frame size is size of camera you can find the code on below link
https://stackoverflow.com/a/30403558
also, focal length you can find below link
Manual focus in camera2, android
and i combine the code like this
A function calculateFOV() calculate FOV angle
https://github.com/pchan1401-ICIL/Camera2FOV
Solution 2
As far as my research has gone the answer is no. With the camera2
API there is no call which can give you the vertical and horizontal viewing angle.
However, you don't need to use the camera2
API to get those values. You can just use the original camera
API to get the vertical and horizontal view angle and then use the camera2
API for the rest of the app.
As far as I know the actual image capture firmware hasn't changed between the camera and camera2
APIs.
Solution 3
You could do it mathematically.
You have:
-
L
, the width of an object -
d
, the distance to the object
You want to calculate the angle a
(alpha), the field of view.
Doing some trig:
tan(a/2) = (L/2)/d
tan(a/2) = L/2d
a/2 = atan(L/2d)
a = 2*atan(L/2d)
You can do that to calculate the horizontal field of view. Good luck!
Solution 4
Using camera2
API we can do it like this:
val cameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
val cameraCharacteristics = cameraManager.getCameraCharacteristics("0") // hardcoded first back camera id
val focalLength = cameraCharacteristics.get(CameraCharacteristics.LENS_INFO_AVAILABLE_FOCAL_LENGTHS)?.firstOrNull() ?: return
val sensorSize = cameraCharacteristics.get(CameraCharacteristics.SENSOR_INFO_PHYSICAL_SIZE) ?: return
val horizontalAngle = (2f * atan((sensorSize.width / (focalLength * 2f)).toDouble())) * 180.0 / Math.PI
val verticalAngle = (2f * atan((sensorSize.height / (focalLength * 2f)).toDouble())) * 180.0 / Math.PI
// using camera2 API we got the same data as with legacy Camera API (with it was easier):
// val parameters = camera.getParameters()
// val horizontalAngle = parameters.getHorizontalViewAngle()
// val verticalAngle = parameters.getVerticalViewAngle()
But usually such values are for 4:3 aspect preview ratio, if you need it for 16:9 aspect ratio or other then check this Without additional calculation Camera or camera2 APIs return FOV angle values for 4:3 aspect ratio by default?
David D.
I'm studing to become an engineer in computer science. I like coding, playing and researching.
Updated on June 25, 2022Comments
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David D. almost 2 years
I want to know the angle of view from the camera, just like in this question but using android.hardware.camera2. How can I reproduce the next code using the new camera2 library.
Camera.Parameters p = camera.getParameters(); double thetaV = Math.toRadians(p.getVerticalViewAngle()); double thetaH = Math.toRadians(p.getHorizontalViewAngle());
Is there a way to do the same thing?
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David D. almost 9 yearsI knew that solution, but it's not what I want because the users would need to do calibration and there are already to many steps before reaching that point and I don't want to overwhelm the users to do a more steps to be able to know the d and L
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Anubian Noob almost 9 yearsOh yeah... Sorry I don't know a better solution :P
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Someone Somewhere over 6 yearsVery nice write-up! I am currently blown-away that Camera 2 API makes it harder on the developer. I thought that successive API sets are meant to increase functionality.
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user924 over 3 yearsvery bad answer, it's possible to calculate, there is sensor size, focal length and other data available.
You can just use the original camera
==Just use deprecated API
- so smart!...