# Filter image¶

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

*Algorithms*:

absComputes absolute value or complex magnitude of image

angleGives the phase angle of a complex image

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

clampRestricts 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

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.

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

imagGives the imaginary part of a complex 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])

normalizeAdds 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

realGives the real valued part of a complex image

scale/offsetAdds 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 integerConverts all channels into integer data

*Input ports*:**source**: imagesource image to filter*Output ports*:**result**: imageresult after filtering*Configuration*:**Algorithm**(algorithm)- (no description)
**scale**(scale)- (no description)
**k**(k)- (no description)
**sigma-y**(sigma-y)- (no description)
**sigma-x**(sigma-x)- (no description)
**maximum**(maximum)- (no description)
**border mode**(border mode)- (no description)
**minimum**(minimum)- (no description)
**offset**(offset)- (no description)
**sigma**(sigma)- (no description)

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