DRIP (version 2.3)

modify2: Type-2 Modification Procedure

Description

Delete deceptive edge pixels that are scattered in the design space.

Usage

modify2(bandwidth, edge, plot)

Value

A matrix of zeros and ones of the same size as the input image.

Arguments

bandwidth

A positive integer that specifies the number of pixels to use in the local smoothing.

edge

A matrix of 0 and 1 representing the detected edge pixels.

plot

If plot = TRUE, images of the detected edges before and after the modification are plotted.

Author

Yicheng Kang

Details

A local-smoothing based edge detection algorithm may flag deceptive edge pixel candidates. One kind of such candidates existis due to the nature of hypothesis testing, on which the threshold value of the edge detection criterion is based. That is, a point \((x_i, y_j)\) could be flagged as a edge pixel with certain probability, even if it is actually not a edge pixel. Deceptive candidates of this kind are scattered in the whole design space. This modification procedure deletes scattered edge pixel candidates.

References

Qiu, P. and Yandell, B. (1997) "Jump Detection in Regression Surfaces," Journal of Computational and Graphical Statistics 6(3), 332-354, tools:::Rd_expr_doi("10.1080/10618600.1997.10474746").

See Also

modify1

Examples

edge <- stepEdge(sar, bandwidth = 4, thresh = 20, degree = 0)
out <- modify2(4, edge)