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How to Use This Tool
This tool helps you calculate the real-world distance between two points in an image, provided you have a
known reference length.
Important: This calculation assumes that the known reference object and the unknown
object being measured are at approximately the same distance from the camera. If depths vary
significantly, this pixel-ratio method is invalid and angular size calculations must be used.
Step 1: Enter the real-world measurement of your known object (e.g., the length of a car
or a building).
Step 2: Enter the pixel coordinates (X,Y format) for the start and end of that known
object (Points 1 & 2).
Step 3: Enter the pixel coordinates for the object you want to measure (Points 3 & 4)
and hit Calculate!
Copyright © John Craig
