ee.Algorithms.Image.Segmentation.GMeans

AI-generated Key Takeaways

• The G-Means algorithm performs clustering on an input image by iteratively applying k-means and a normality test to automatically determine the number of clusters.

• The output image includes a 'clusters' band indicating the cluster ID for each pixel.

• The algorithm can operate on a fixed grid or overlapping tiles, with the default being non-overlapping tiles.

• Clusters are independent across cells or tiles, meaning a cluster spanning a boundary may receive different labels on each side.

• This algorithm is best suited for images with a narrow dynamic range (e.g., bytes or shorts).

Performs G-Means clustering on the input image. Iteratively applies k-means followed by a normality test to automatically determine the number of clusters to use. The output contains a 'clusters' band containing the integer ID of the cluster that each pixel belongs to. The algorithm can work either on a fixed grid of non-overlapping cells (gridSize, which can be smaller than a tile) or on tiles with overlap (neighborhoodSize). The default is to use tiles with no overlap. Clusters in one cell or tile are unrelated to clusters in another. Any cluster that spans a cell or tile boundary may receive two different labels in the two halves. Any input pixels with partial masks are fully masked in the output. This algorithm is only expected to perform well for images with a narrow dynamic range (i.e., bytes or shorts).

See: G. Hamerly and C. Elkan. 'Learning the k in k-means'. NIPS, 2003.

Usage	Returns
ee.Algorithms.Image.Segmentation.GMeans(image, numIterations, pValue, neighborhoodSize, gridSize, uniqueLabels)	Image

Argument	Type	Details
image	Image	The input image for clustering.
numIterations	Integer, default: 10	Number of iterations. Default 10.
pValue	Float, default: 50	Significance level for normality test.
neighborhoodSize	Integer, default: 0	Neighborhood size. The amount to extend each tile (overlap) when computing the clusters. This option is mutually exclusive with gridSize.
gridSize	Integer, default: null	Grid cell-size. If greater than 0, kMeans will be run independently on cells of this size. This has the effect of limiting the size of any cluster to be gridSize or smaller. This option is mutually exclusive with neighborhoodSize.
uniqueLabels	Boolean, default: true	If true, clusters are assigned unique IDs. Otherwise, they repeat per tile or grid cell.