Shape correction#

Shape corrections change the geometry of the pixel container – dewarping lens curvature, straightening perspective, aligning frames that have shifted. They derive from BaseCorrection and are usually passed to imread() via transformations=.

`CurvatureCorrection`	crop and dewarp to the four rig corners; the workhorse for wide-angle FluidFlower photos
`AffineCorrection`	affine map from matched point pairs
`GeneralizedPerspectiveCorrection`	perspective / homography, incl. piecewise
`DriftCorrection`	compensate small frame-to-frame camera drift using a fixed reference patch
`DeformationCorrection`	apply a known displacement field
`TranslationCorrection`	pure translation; `TranslationEstimator` finds it from image features
`RotationCorrection`	rigid rotation
`ResizeCorrection`	rescale (also available as `resize()` / `Resize`)

import json, darsia

cfg = json.load(open("config.json"))
curvature = darsia.CurvatureCorrection(config=cfg["curvature"])

photo = darsia.imread("photo.jpg", transformations=[curvature],
                      width=2.8, height=1.5)

The stand-alone transforms (AffineTransformation, GeneralizedPerspectiveTransformation, PiecewisePerspectiveTransform) can also be used directly on arrays of points.

Note

Shape corrections change pixels and keep the physical metadata consistent. To align two images by editing only their metadata, use CoordinateTransformation (see Coordinate systems).

Shape correction#

See also#