ee.Image.displacement

Page Summary

• Computes local image displacements for registration while allowing rubber sheet deformations.

• Displacements are computed in the reference image's CRS at a scale based on the lowest resolution of three projections: input, reference, and requested.

• The resulting displacements are transformed into the user-specified output projection.

Determines displacements required to register an image to a reference image while allowing local, rubber sheet deformations. Displacements are computed in the CRS of the reference image, at a scale dictated by the lowest resolution of the following three projections: input image projection, reference image projection, and requested projection. The displacements are then transformed into the user-specified projection for output.

Usage	Returns
Image.displacement(referenceImage, maxOffset, projection, patchWidth, stiffness)	Image

Argument	Type	Details
this: image	Image	The image to register.
referenceImage	Image	The image to register to.
maxOffset	Float	The maximum offset allowed when attempting to align the input images, in meters. Using a smaller value can reduce computation time significantly, but it must still be large enough to cover the greatest displacement within the entire image region.
projection	Projection, default: null	The projection in which to output displacement values. The default is the projection of the first band of the reference image.
patchWidth	Float, default: null	Patch size for detecting image offsets, in meters. This should be set large enough to capture texture, as well as large enough that ignorable objects are small within the patch. Default is null. Patch size will be determined automatically if not provided.
stiffness	Float, default: 5	Enforces a stiffness constraint on the solution. Valid values are in the range [0,10]. The stiffness is used for outlier rejection when determining displacements at adjacent grid points. Higher values move the solution towards a rigid transformation. Lower values allow more distortion or warping of the image during registration.