Color range conversion

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

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]

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