CV-0.3.7: OpenCV based machine vision library

Safe HaskellNone




This module contains functions for extracting features from connected components of black and white images as well as extracting other shape related features.


Working with connected components

selectSizedComponents :: Double -> Double -> Image GrayScale D8 -> Image GrayScale D8Source

Remove all connected components that fall outside of given size range from the image.

countBlobs :: Image GrayScale D8 -> IntSource

Count the number of connected components in the image

Working with Image moments

Note that these functions should probably go to a different module, since they deal with entire moments of entire images.

spatialMoments :: Image GrayScale D32 -> Bool -> [Double]Source

Extract raw spatial moments of the image.

centralMoments :: Image GrayScale D32 -> Bool -> [Double]Source

Extract central moments of the image. These are useful for describing the object shape for a classifier system.

normalizedCentralMoments :: Image GrayScale D32 -> Bool -> [Double]Source

Extract normalized central moments of the image.

huMoments :: Image GrayScale D32 -> Bool -> [Double]Source

Extract Hu-moments of the image. These features are rotation invariant.

Working with component contours aka. object boundaries.

This part is really old code and probably could be improved a lot.

data Contours Source

Structure that contains the opencv sequence holding the contour data.

getContours :: Image GrayScale D8 -> ContoursSource

Extract contours of connected components of the image.

contourArea :: ContourFunctionUS DoubleSource

The area of a contour.

contourPerimeter :: ContourFunctionUS DoubleSource

Get the perimeter of a contour.

contourPoints :: ContourFunctionUS [(Double, Double)]Source

Get a list of the points in the contour.

mapContours :: ContourFunctionUS a -> Contours -> [a]Source

This function maps an opencv contour calculation over all contours of the image.

contourHuMoments :: ContourFunctionUS [Double]Source

 Operation for extracting Hu-moments from a contour