threeStage {DRIP} R Documentation

## Denoising, deblurring and edge-preserving

### Description

Estimate surface using local smoothing and fitting principal component line. Bandwidth is specified by user.

### Usage

threeStage(image, bandwidth, edge1, edge2,
blur = FALSE, plot = FALSE)

### Arguments

 image A square matrix object of size n by n, no missing value allowed. bandwidth A positive integer that specifies the number of pixels used in the local smoothing. edge1 A matrix of 0 and 1 of the same size as image represents detected step edge pixels edge2 A matrix of 0 and 1 of the same size as image represents detected roof/valley edge pixels blur If blur = TRUE, besides a conventional 2-D kernel function, a univariate increasing kernel function is used in the local kernel smoothing to address the issue with blur. plot If plot = TRUE, the image of the fitted surface is plotted

### Details

At each pixel, if there are step edges detected in the local neighborhood, a principal component line is fitted through the detected edge pixels to approximate the step edge locally and then the regression surface is estimated by a local constant kernel smoothing procedure using only the pixels on one side of the principal component line. If there are no step edges but roof/valley edges detected in the local neighborhood, the same procedure is followed except that the principal component line to fitted through the detected roof/valley edge pixels. In cases when there is either no step edges or roof/valley edges detected in the neighborhood, the regression surface at the pixel is estimated by the conventional local linear kernel smoothing procedure.

### Value

Returns the restored image, which is represented by a matrix

### References

Qiu, P., and Kang, Y. "Blind Image Deblurring Using Jump Regression Analysis," Statistica Sinica, 25, 2015, 879-899.

JPLLK_surface, surfaceCluster
data(sar)