Establishing a demerit count reference standard for the classification and grading of leather hides

Abstract

Leather hide, as a natural material, may have many types of undesirable surface defects. No analytical method has been devised for classifying and grading wet blue hide surface defects. A high return rate and disputes between the customer and manufacturing company usually cause additional costs. This paper proposes a semi-automatic machine vision method to measure the unusable surface defect areas in wet blue hides and a clear reference standard for the demerit count for graders to classify and grade wet blue hides. A statistical comparative evaluation of the grade deviation rate and a practical demerit count method for tannery performance are given to show the usefulness of the proposed approach.