Fits a 2D projective transform between two point sets with RANSAC at a caller-ch
Fits a 2D projective transform between two point sets with RANSAC at a caller-chosen reprojection threshold, and returns both the homography and the inlier mask. The mask is what makes this useful beyond a plain fit: bad correspondences are named rather than quietly averaged in, so a caller can re-run detection, drop a frame or raise an alarm. Suitable for document rectification, planar tracking and image stitching where the scene really is flat.
Answeringour last check, 2026-10-25
1 of 1checks answered this week
1226 msmedian answer time
$0.002listed price per call
$0.002price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://medien.halowerk.com/v1/oss-opencv-robust-planar-homography
| Category | Image and media |
|---|---|
| Provider host | medien.halowerk.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 0 from 0 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-25 | valid payment request | 402 | $0.002 | 1226 ms |
Example input (from the provider)
{
"body": {
"reprojection_threshold": 1,
"source_points": [
[
5,
10
],
[
35,
10
],
[
70,
10
],
[
100,
10
],
[
5,
50
],
[
35,
50
],
[
70,
50
],
[
100,
50
],
[
5,
90
],
[
35,
90
],
[
70,
90
],
[
100,
90
]
],
"target_points": [
[
16.923842707814835,
4.081632653061225
],
[
51.986267778322706,
4.61010299166258
],
[
91.61041465766635,
5.207328833172614
],
[
124.52471482889733,
5.703422053231939
],
[
20.74074074074074,
39.604938271604944
],
[
55.47445255474452,
39.61070559610705
],
[
94.73684210526316,
39.61722488038278
],
[
127.35849056603773,
39.62264150943396
],
[
24.497795198432144,
74.57128858402744
],
[
58.90873973925639,
74.07049734427812
],
[
97.81576448243115,
73.50427350427351
],
[
180.1498127340824,
13.033707865168537
]
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Numeric JSON arrays only. Additionally enforce equal paired dimensions, nondegenerate geometry, maximum 32768 pixels/image, 131072 scalars/array, and 1048576 encoded bytes. No paths or network resources.",
"properties": {
"reprojection_threshold": {
"maximum": 10,
"minimum": 0.1,
"type": "number"
},
"source_points": {
"items": {
"items": {
"maximum": 1000000000,
"minimum": -1000000000,
"type": "number"
},
"maxItems": 2,
"minItems": 2,
"type": "array"
},
"maxItems": 2048,
"minItems": 4,
"type": "array"
},
"target_points": {
"items": {
"items": {
"maximum": 1000000000,
"minimum": -1000000000,
"type": "number"
},
"maxItems": 2,
"minItems": 2,
"type": "array"
},
"maxItems": 2048,
"minItems": 4,
"type": "array"
}
},
"required": [
"source_points",
"target_points",
"reprojection_threshold"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"additionalProperties": false,
"properties": {
"operation": {
"const": "robust-planar-homography"
},
"result": {
"additionalProperties": false,
"properties": {
"homography": {
"items": {
"items": {
"type": "number"
},
"maxItems": 3,
"minItems": 3,
"type": "array"
},
"maxItems": 3,
"minItems": 3,
"type": "array"
},
"inlier_count": {
"maximum": 2048,
"minimum": 4,
"type": "integer"
},
"inlier_mask": {
"items": {
"type": "boolean"
},
"maxItems": 2048,
"minItems": 4,
"type": "array"
},
"warnings": {
"items": {
"maxLength": 1024,
"type": "string"
},
"maxItems": 8,
"minItems": 1,
"type": "array"
}
},
"required": [
"homography",
"inlier_mask",
"inlier_count",
"warnings"
],
"type": "object"
},
"runtime_ms": {
"minimum": 0,
"type": "number"
},
"upstream": {
"additionalProperties": false,
"properties": {
"binary_sha256": {
"const": "1fd4eb220f9986baa0ea0492cbcbedf85b868e792cbcac5f69e10d067a2f956c"
},
"components": {
"const": [
"findHomography"
]
},
"numpy_version": {
"const": "2.5.0"
},
"package_version": {
"const": "4.13.0.92"
},
"project": {
"const": "OpenCV"
},
"version": {
"const": "4.13.0"
}
},
"required": [
"project",
"version",
"package_version",
"binary_sha256",
"numpy_version",
"components"
],
"type": "object"
}
},
"required": [
"operation",
"result",
"upstream",
"runtime_ms"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}