mask: create tunable parametric masks for use with blending

this module allows you to mask regions of the input image based on luminance and colour ranges

parameters

mode select based on which property: luminance, hue, or saturation
vmin the floor level of the mask
vmax the maximum value of the mask
envelope four values to define the begin and end of ease-in and ease-out of an envelope function

connectors

input the input colour image
output the mask created for the image. plug this into a blend module for instance.