Equation to measure meters from pictures

Hi,

I am measuring the distance between the centroid of bounding boxes for detected objects in pixels in the images .I am looking for an equation which convert the measurment in pixels into meters .

Best

[Matt Gaidica]

You're going to need a reference in your frame—do you have that? (e.g., a ruler) Once you have that, you have some ratio of pixels/meters, and you divide your object pixel distances by that to get your answer.

Answer 1

[Rishabh Mishra]

Hi,

To find distance between 2 points, you require their co-ordinates. Assuming co-ordinates for 2 points are stored in arrays x & y respectively. The distance ‘D’ between these 2 points is given by,

x= [1 2 3]; 
y= [3 4 5]; 
D = norm(x-y); 

The distance value so obtained has units as pixels. Convert pixels into meters using the conversion value given below:

1 pixel = 0.0002645833 m

Hope this helps.

[Image Analyst]

Where did you get that number?

Answer 2

[Image Analyst]

See my spatial calibration demo. It will show you how you can get the meters per pixel, or whatever real world units you're using.