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# RidgeFilter

 RidgeFilter[image] computes a measure for the presence of a ridge for each pixel in image. RidgeFilteruses the specified ridge scale .
• RidgeFilter computes the main principal curvature at each pixel.
• The main principal curvature orthogonal to a ridge is given by the main negative eigenvalue of the Hessian matrix.
• In RidgeFilter, is the scale of the ridges that is used to compute the derivatives in the Hessian.
• RidgeFilter works with arbitrary grayscale or multichannel images, operating separately on each channel.
• RidgeFilter returns a real image of the same dimensions as image.
• RidgeFilter[array] computes the ridges in a two-dimensional array.
• RidgeFilter supports the following options to compute the Hessian matrix and the main principal curvature:
 InterpolationOrder Automatic interpolation order Padding "Fixed" padding method
• The Padding option accepts the settings , , , , or a numeric value. A list of two settings can specify different paddings for each dimension.
Detect lines of a given width in a noisy image with uneven brightness:
Find the mountain ridges in a terrain elevation raster:
Enhance the strokes of handwritten characters:
Detect lines of a given width in a noisy image with uneven brightness:
 Out[1]=

Find the mountain ridges in a terrain elevation raster:
 Out[1]=

Enhance the strokes of handwritten characters:
 Out[1]=
 Applications   (2)
Extract lines of a given thickness:
Find the red ridges in a microscopic photo of a Yucca leaf:
Extract the thin walls:
New in 8