The process aligns a source image to a reference image. Its algorithm automatically detects and minimizes misalignments between features using rigid-body transformation. The results are GeoTIFF files of matching optical assets with improved positional accuracy.
Coregistration can be used as a preprocessing step before change detection, data fusion, and DEM generation.
A reference image of Berlin (Germany)
A source image that hasn't been coregistered
A coregistered output image
See more on the marketplace.
The coregistration algorithm aligns images accurately, even if they have different resolutions or sensor types. It can handle clouds and land cover changes. It calculates sub-pixel shifts by analyzing local image patches, then aligns the images using rigid-body translation and rotation.
For better performance, ensure the following:
- Both STAC items have matching geometric and radiometric processing levels.
- The GSD of the two STAC items shouldn’t differ by more than 25%.
Both STAC items must be CNAM-compatible. CNAM-compatible data meets both criteria:
- The data was added to storage starting in 2023.
- The data comes from a supported collection.
Both STAC items must be georectified or orthorectified. To check whether the chosen collections provide the necessary geometric processing level, see Geometric processing levels.
The STAC items must have matching multispectral or panchromatic STAC assets.
The geometries of the STAC items must overlap by at least 20%.
The cloud coverage of the STAC items must be less than 25%.
Required parameters
Source STAC item
You need to specify the STAC item for the source image you want to coregister.
Reference STAC item
You need to specify the STAC item for the reference image for coregistration. The positional accuracy of the source image will be improved against this reference.
Output title
You need to specify the title of the output object. This title will be assigned to the resulting STAC item and STAC collection.
Use the coregistration-simularity name ID for the processing API.
A sample input payload for the process
JSON
{
"inputs": {
"title": "Coregistering imagery over Berlin",
"sourceItem": "https://api.up42.com/v2/assets/stac/collections/21c0b14e-3434-4675-98d1-f225507ded99/items/23e4567-e89b-12d3-a456-426614174000",
"referenceItem": "https://api.up42.com/v2/assets/stac/collections/21c0b14e-3434-4675-98d1-f225507ded99/items/edeb6310-ea9a-4d8e-943d-11a5f3757824"
}
}
| Parameter | Overview |
|---|---|
inputs.title | object / required The title of the output objects: STAC item and STAC collection. |
inputs.sourceItem | array of strings / required The source STAC item link in the following format: https://api.up42.com/v2/assets/stac/collections/{collection-id}/items/{item-id} |
inputs.referenceItem | array of strings / required The reference STAC item link in the following format: https://api.up42.com/v2/assets/stac/collections/{collection-id}/items/{item-id} |