Operators of contrast modification of fuzzy sets

When a vague value is expressed by a fuzzy set, its fuzziness (vagueness) is measured with respect to the threshold α=0.5. This point is the equilibrium of the standard fuzzy complement. It also separates "large" and "small" membership coefficients of a fuzzy set when the operator of contrast intensification (diminishment) is used to decrease (increase) the amount of fuzziness of a fuzzy set. For α ∈ (0, 1) more general operators of α-contrast intensification and α-contrast diminishment based on fuzzy complement with equilibrium equal to α will be introduced, discussed and illustrated with examples