android - How to find the object length using camera in android

Question

i want to find the object length using camera . I have search a lot and i have found relation between distance & view angle. Formula angle= arctan(d/2f) but i m frustrated and not find any relative code. so please suggest me the working code in order to find the object height using camera. if distance from the object is know then how to find the object length Thanks in advance

Answer 1

verticalViewAngleDegrees = myCamera.getParameters().getVerticalViewAngle();
heightOfObjectFillingImage = 2 * userSpecifiedDistance * tan(toRadians(verticalViewAngleDegrees/2));
approxHeightOfObject = verticalPixelsOfObject / verticalPixelsOfWholeImage * heightOfObjectFillingImage;

我不相信三角函数是我能做的最好的，但这是第一个近似值。