Evaluation of microenvironment cleanliness for computer assisted sperm analysis system based on fusion of neutrosophic feasures

•This paper innovatively proposes to research CASA quality control from the perspective of image processing.•An indicator measuring microenvironment cleanliness is innovatively proposed to reduce the variability of CASA diagnosis results.•Neutrosophy is introduced to solve indeterminacy in non-sperm target extraction.•A Neutrosophic gradient quantization function with an adjustable factor has been presented.•An effective non-sperm target extraction algorithm based on the function of neutrosophic grayscale and neutrosophic gradient has been proposed.