SiliconAperture

Drop image here

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Enter sensor parameters

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Mark measurement on photo

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Mark distance on map

Drop a photo here
or click to browse

scroll to zoom · drag to pan · click twice to mark object extent

Image Mensuration

Camera

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Focal length

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Image size

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GPS

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Sensor EXIF DB CUSTOM

mm W

mm H

mm f

Object span click two points on photo

Distance

Real-world size

— m

Distance camera position → object position

How to use SiliconAperture

Drop a photo onto the left panel.
If the image contains EXIF metadata, camera model, sensor and focal length are detected automatically. Otherwise select your camera from the dropdown or enter sensor dimensions and focal length manually.
Click two points on the photo to mark the object's extent. The pixel span fills in.
Enter the distance to the object in meters, or click two points on the satellite map to measure it.
The real-world size appears as soon as all four inputs are valid.

Flip the Solve for toggle to Distance to work it the other way: enter an object's known real-world size and the tool returns the distance to it, then click the object on the satellite map to draw a ring of possible camera positions.

Solve for size

size = √( (D·tan(Δx/W·sw/f))² + (D·tan(Δy/H·sh/f))² )

Solve for distance

D = size / √( tan(Δx/W·sw/f)² + tan(Δy/H·sh/f)² )

D	distance to object	f	focal length
Δx, Δy	pixel span per axis	W, H	image width / height
sw, sh	sensor width / height

Each axis is solved independently with its matching sensor dimension, then the two real-world components are combined with Pythagoras. Works for marks at any angle.

Accurate results require the object to be perpendicular to the camera axis. If the surface is angled, the apparent extent seen by the lens no longer maps linearly to the true physical size, and the result will be inaccurate.

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