Can I turn a room photo into a top-down floor plan?

Yes, for a visible flat plane. Jarvis uses four corners of a known card or A4 sheet and user-confirmed footprint vertices to correct perspective into a measurable top-down polygon.

Can blank A4 paper calibrate a room photo?

Yes. A flat, undamaged A4 sheet provides a known 210 by 297 millimetre rectangle when all four corners are visible on the same plane as the traced footprint.

Does the photo tool recognize hidden walls?

No. The current tool transforms confirmed points on one visible plane. It does not infer hidden corners, vertical surfaces, floor slope or building-code compliance.

Exact-size calibration method

Print, verify, place and scan.

The sheet uses physical CSS millimetres: A4 is 210 × 297 mm and the Jarvis card is exactly 88.90 × 50.80 mm (3.5 × 2 in). Never trust the printer dialog alone—measure the printed checks before scanning.

1
Print at Actual size / 100%
Select A4 paper, portrait orientation, no “Fit to page,” and turn off browser headers and footers.
2
Verify the A4 relationship
The page is 210 mm wide. Its inner frame is 190 mm wide because it sits 10 mm from each edge.
3
Measure both 100 mm rulers
Each major division is 10 mm and each small division is 1 mm. Both bars must measure exactly 100 mm with a physical ruler.
4
Verify the card
The red card boundary must measure 88.90 × 50.80 mm. If any check is wrong, correct printer scaling and print again.
5
Keep it on the measurement plane
Place the card flat on the same floor, wall or board as the dimension. Keep all four corner targets visible and avoid glare.

How the calculation works

You tap the card’s four corners in order. Jarvis maps that photographed quadrilateral back to the known 3.5 × 2-inch rectangle. You then tap two points on the same plane; the projective mapping converts their pixel positions into inches.

4 image corners → known card plane → homography → two points → real distance

Important: this method corrects a flat plane. It cannot accurately measure around corners, across different wall depths, or through an object.

Print previewA4 · 210 × 297 mm

JARVIS SCAN CARDHomeUpgraders Studio · calibration sheet v1

A4 · 100%

PRINT AT ACTUAL SIZE / 100%Do not use “Fit to page.” Verify all three physical checks below before use.

✦

JARVISPLANAR CALIBRATION

88.90 × 50.80 mm
3.5 × 2.0 in

X · 88.90 mm

Y · 50.80 mm

PHYSICAL PRINT VERIFICATION

0102030405060708090100

Horizontal ruler: exactly 100 mm · major marks 10 mm · minor marks 1 mm

0102030405060708090100

50 mmCHECK SQUARE

A4 relationship

Sheet: 210 × 297 mm

Frame: 190 × 277 mm

Margins: 10 mm each side

Card: 88.90 × 50.80 mm

Five-photo or native depth result

Use a completed room scan

Import the scanner JSON directly. Current Android/Apple captures use the canonical scan contract; older registered card/A4 results remain supported.

The room editor only accepts a confirmed rectangle or six-corner L-shape today. More complex canonical polygons remain preserved by the scan pipeline instead of being silently simplified.

On-device calibration

Capture or upload a calibrated measurement

2of 2 free scans left

Take a new photo or upload an existing image with the Scan Card lying on the same flat plane as the measurement. The image remains in this browser and is not uploaded by this tool.

Photo workspace

Take a photo now or use a project image you already have.

Layout Library evidence gate

6 checks remaining

The Layout Library button stays blocked until the source, calibration and visible measurement references are complete.

Choose whether the scan came from the camera or uploaded images.
Add a source image before using the scan in the Layout Library.
Reference all required calibration points.
Reference both measurement points.
Produce a finite calibrated measurement.
Confirm that the referenced evidence matches the visible measurement.

Use measurement as

Perspective → plan view

Create a calibrated top-down footprint from a photo

Take or choose one photo containing the reference and the floor outline. The image stays in this browser and is not uploaded.

Reference plane

Known reference on the same flat planeJarvis card88.90 × 50.80 mmBlank A4 · portrait210 × 297 mmBlank A4 · landscape297 × 210 mm

Take or choose photo

Perspective photo

Keep the entire reference and every visible footprint corner in frame.

Top-down result

The transformed polygon appears after at least three footprint points are finished.

Evidence boundary

This is a user-confirmed planar transform, not automatic room recognition. The reference and all outline points must lie on one physical plane.

Plain-language answers

Questions Orléans homeowners ask about photo measurement

Can a room photo become a top-down floor plan?

It can become a calibrated planar footprint when a known reference and the visible boundary lie on the same flat surface.

Can I use blank A4 paper?

Yes. Select portrait or landscape, keep all four sheet corners visible and confirm the paper is flat and undamaged.

Is this automatic AI room recognition?

No. Today’s production-intent baseline uses human-confirmed evidence. Computer vision may propose corners later, but it must not silently invent geometry.