Sheet Measure & Height Spray

The brief

A sheet in front of a camera is not yet a size. Raise the camera and the same paper fills fewer pixels. A sprayer that was set at one height then covers the wrong patch.

The work was a detector for the paper, a calculator that turns the frame into millimetres, and a sprayer that takes the camera height as an input. The person who commissioned it is under NDA.

The challenge

Detection without a unit is a box. A unit without the height is a guess.

• Find the sheet in the frame, and say so on the image, not in a log nobody is watching
• Report width, height and area in pixels and in millimetres
• Keep that millimetre reading honest when the camera moves up or down
• Let the sprayer follow that height, instead of a fixed pattern that was right once

How we approached it

The camera looks first. The sheet is outlined on the live frame, with a confidence, so an operator can see what was found before anything sprays.

Pixels become millimetres from the height of the camera. The same sheet should not grow because someone raised the rig. Width, height and area are written on the frame in both units.

The sprayer reads that height. A higher camera sees a larger patch of the surface, so the spray changes with it rather than repeating the last setting.

What we built

A paper detector, an area calculator on the camera, and an automated sprayer tied to camera height. The first photograph is the sheet, outlined. The second is a measured object with its live reading: width, height and area, in pixels and millimetres.

We do not publish the client's name, the fluid, or a claimed accuracy. The overlay is the measurement. It is not a benchmark we invented.

Results

The engagement is under NDA. We do not publish who it was built for, spray volumes, or an error figure.

In use

A new height is a new reading of the same camera. The sheet is still found. The area is still in millimetres. The spray still follows.