I'm trying to determine the degree size of the field-of-view of a Droid Incredible smartphone's camera. I need to know this value for an application that I'm developing. Does anyone know how I can find out/calculate it programmatically?
+1
A:
Unless there's some API call for that (I'm not an Android programmer, I wouldn't know), I would just snap a picture of a ruler from a known distance away, see how much of the ruler is shown in the picture, then use trigonometry to find the angle. Then you can hard-code it as a constant in your program. (A named constant, of course, so it'd be easy to change :-p)
David Zaslavsky
2010-07-16 03:47:01
Better yet, make it user-configurable so people who don't have a Droid Incredible can adjust/calibrate it.
EboMike
2010-07-16 03:57:36
This value would change with zoom level, of course.
emddudley
2010-07-16 03:58:14
@emddudley: true, I never thought about the phone having a zoom level. Although given the view angle at any one zoom level, it should be possible to calculate it at any other zoom level.
David Zaslavsky
2010-07-16 04:01:13
A:
I have a Droid Incredible as well. Android 2.2 introduced the functions you are looking for. In my code, I have:
public double getHVA() {
return camera.getParameters().getHorizontalViewAngle();
}
public double getVVA() {
return camera.getParameters().getVerticalViewAngle();
}
However, these require that you have the camera open. I'd be interested to know if there is a "best practices" way to not have to open the camera each time to get those values.
@David Zaslavsky - how? What is the mathematical relationship between the zoom levels? I can't find it anywhere (I asked in this question: http://stackoverflow.com/questions/3682149/what-do-the-android-camera-zoom-numbers-mathematically-represent)
Max
2010-09-10 03:57:24