Filter image

Some of the docstrings for this module have been extracted from the scikit-image library and are covered by their respective licenses.

class node_general_filters.GeneralImageFiltering

Applies simple filtering or scaling algorithms on an image. For more complex operations see the more specialized image manipulation nodes

Algorithms:

• abs

  Computes absolute value or complex magnitude of image

• angle

  Gives the phase angle of a complex image

• center image

  Shifts image so that center of mass lies in center of image

• clamp

  Restricts the output values to a given maximum/minimum

  minimum:

  The minimum output value that can be passed through

  maximum:

  The maximum output value that can be passed through

• gaussian

  Two-dimensional Gaussian filter

  sigma-x:

  Standard deviation of gaussian filter along X-axis

  sigma-y:

  Standard deviation of gaussian filter along Y-axis

  border mode:

  Determines how the array borders are handled

  k:

  Value outside image borders when method constant is used.

• hessian determinant

  Computes an approximation of the determinant of the hessian matrix for each pixel.

  sigma:

  Standard deviation of gaussian kernel (default 3.0) used for calculating Hessian.

  Approximation is not reliable for sigma < 3.0

• imag

  Gives the imaginary part of a complex image

• integral image

  Creates the integral image of the input.

  An integral image contains at coordinate (m,n) the sum of all values above and to the left of it.

  S(m,n) = sum(im[0:m, 0:n])

• normalize

  Adds a (positive) scale and offset so that smallest/highest value in image becomes 0 and 1 respectively.

  Operates on each channel separately

  minimum:

  Minimum value after normalization

  maximum:

  Maximum value after normalization

• real

  Gives the real valued part of a complex image

• scale/offset

  Adds a scale and/or an offset to each channel equally

  scale:

  Scale factor applied to image before offset

  offset:

  Offset applied to image after scale

• to integer

  Converts all channels into integer data

Inputs:

source : image

source image to filter

Outputs:

result : image

result after filtering