Color range conversion

../../../../_images/image_color_range.svg

Changes the range and distribution of values for all pixels

Algorithms:
  • adaptive histogram

    Improves contrast by stretching and equalizing the histogramin a sliding window over the image

    bins:

    Number of bins in computed histogram (default 256)

    adaptive kernel size:

    Size of the sliding window. Must evenly divide both image width and height.

    sigma:

    Clipping limit (normalized between 0 and 1). Higher values give more contrast. (default 1.0)

  • gamma correction

    Applies the correction: Vout = scale Vin^gamma

    Processes each channel separately

    scale:

    Constant scale factor applied after gamma correction

    gamma:

    Gamma factor applied to image.

    <1 increases intensities of mid-tones,

    >1 decreases intensities of mid-tones

  • histogram equalization

    Improves contrast by stretching and equalizing the histogram

    bins:

    Number of bins in computed histogram (default 256)

  • log correction

    Applies the correction: Vout = scale log(1 + Vin)

    Processes each channel separately

    scale:

    Constant scale factor applied after gamma correction

    inverse:

    Perform inverse log-correction instead (default false):

    Vout = scale (2^Vin - 1)

  • sigmoid

    Performs Sigmoid correction on input image. Also known as contrast adjustment.

    Vout = 1/(1+exp(gain*(cutoff-Vin)))

    Processes each channel separately

    inverse:

    Perform negative sigmoid correction instead (default false)

    cutoff:

    Shifts the characteristic curve for the sigmoid horizontally(default 0.5)

    gain:

    Gain of sigmoid, affects rise time of curve (default 10.0)

Inputs:

source : image

source image to filter

Outputs:

result : image

result after filtering

Ports:

Inputs:

source:

image

source image to filter

Outputs:

result:

image

result after filtering

Configuration:

algorithm
(no description)
gamma
(no description)
inverse
(no description)
adaptive kernel size
(no description)
cutoff
(no description)
scale
(no description)
gain
(no description)
sigma
(no description)
bins
(no description)

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

class node_colors.ColorRangeConversion[source]