KECA Specifier — Room photo & floor calibration

1Add a photo

Choose a photo Take a photo

Shoot the floor at an angle, not straight down — a straight-down shot carries no information about the lens, and the tool will have to assume one. Get a rectangle you can measure well inside the frame. You can also drag an image file onto the photo area.

No photo yet.

Use Choose a photo above, or on a phone Take a photo to shoot the room now. Nothing is uploaded.

Add a photograph of the room to begin.

Mouse or finger: tap each corner in turn; drag a corner to adjust it. A magnifier appears while you drag. Keyboard: Tab to the photo, move the crosshair with the arrow keys and press Enter to place a corner. Once all four are down, press 1–4 to pick a corner (or Tab to step through them) and the arrow keys nudge it — hold Shift for 10 px steps, Alt for quarter-pixel steps. Backspace removes the last corner, and Esc leaves the photo.

2Mark four floor corners

Pick a rectangle that is really on the floor — floor tiles, a rug, a slab joint, the base of a wall. Click the corners in order around the shape, not diagonally across it. Either way round is fine.

The first edge you mark, corner 1 to corner 2, is the width. The second, corner 2 to corner 3, is the depth. Bigger is better: a rectangle spanning several floor tiles calibrates far more accurately than one tile, because every pixel of aim error is diluted across a longer edge.

3Its real size

Measure it. Do not use a remembered standard size — a door you assume is 32" (813 mm) and is actually 33" (838 mm) puts that error on every dimension in the picture, invisibly. No default is offered here for the same reason.

Width (corner 1 → 2)

Depth (corner 2 → 3)

What to use as an anchor

Anything flat, rectangular and on the floor, whose real size you can put a tape on:

Floor tiles or pavers — the best anchor there is. Measure one, count how many the rectangle spans, and use the helper below.
A door opening — measure the frame, and mark the rectangle on the floor between the jambs and the threshold.
A rug, a table top, a bar counter footprint — anything you can reach with a tape.
A slab or expansion joint — outdoors and poolside, these run long and straight, which makes them excellent.
A sheet of paper you brought — US Letter is 11.0" × 8.5" (279 × 216 mm), A4 is 11.7" × 8.3" (297 × 210 mm). Small, so use it only when there is nothing larger, and lay it flat.

Measure from floor tiles

Every number here is yours. The tool offers no standard tile size, because a standard that is an eighth of an inch out would be an eighth of an inch out on everything you read off the picture.

One tile, measured edge to edge

Tiles across

Tiles deep

4Check the calibration

Look at the grid, not at the numbers. Every square is one metre — 39.4" (1,000 mm). If it lies flat on the floor, runs parallel to the real lines in the room and does not skew or climb the walls, the calibration is good. If it does not, no number below will save it.

Show the floor grid Show the horizon (eye level) Show 39.4" (1 m) uprights

Grid spacing

The spacing is never widened behind your back. If a grid would run to hundreds of lines the area covered is trimmed instead, so a square you measure on screen is always the spacing shown here.

What was recovered

Calibrated

Camera height above the floor The one number you can sanity-check without any of the maths: standing is about 1.5–1.7 m, seated about 1.1 m.	—
Horizontal field of view	—
Focal length Solved from your rectangle, taken from the photo's EXIF, or assumed. If it says assumed, sizes may be off and the page says so above.	—
Rectangle fit Two independent estimates of the focal length. Far apart means the shape you marked is not quite a rectangle. Measured against known cameras: under 2 % typically costs well under 1 % of size, around 5 % costs about 3 %, and 12 % costs about 6 %. Anything from 5 % up is flagged below.	—
Floor axes out of square 1.000 : 1 is perfect. Measured against known cameras: up to 1.02 typically costs well under 1 % of size, 1.05 about 3 %, 1.10 about 6 %. Anything from 1.05 up is flagged below.	—
Solver residual Four points give an exactly determined solve, so this is near zero for any four points. It checks the tool, not your clicking.	—

5Choose a finish

Every colour offered here is one KECA publishes for that exact product, with the name KECA publishes it under. Pick by name — that is what goes on a schedule.

This browser tab

Nothing is being kept yet.

Read before specifying

This is a visualisation, not a measured drawing. Furniture is placed at its published size on a floor plane calibrated from four points you marked. Accuracy depends on that calibration. Models are drawn in front of everything already in the photo — the tool has no depth information about the room and cannot put a piece behind an existing object. Dimensions shown come from the KECA catalog; where a value has not been published it reads Pending. Nothing here is estimated on your behalf.

The camera is assumed to have square pixels, no skew, and its optical centre at the middle of the frame. That holds for phone and DSLR photographs and it is what makes a four-point solve possible at all — but it is an assumption, and it is stated here rather than buried.

Lens distortion is not corrected, and it has not yet been measured on a real photograph. The maths assumes a straight line in the room is a straight line in the picture. Wide-angle and ultra-wide phone lenses bend it, most towards the edges of the frame — so a rectangle marked near the edge of a wide shot will calibrate less accurately than the numbers on this page suggest, and this tool cannot tell you by how much. Mark a rectangle nearer the middle of the frame, avoid the ultra-wide lens, and treat the grid, not the readout, as the check.

Even a calibration that passes every check on this page carries a few per cent of scale error. Over a yard that is a fraction of an inch; over a long banquette run it is not. Use this to see whether a piece suits a room, and the published specification — never a measurement taken off this picture — to decide whether it fits.