Method for quantitative description of surface color and luster degree of galvanized plate

The invention provides a method for quantitative description of the surface color and luster degree of galvanized plates. The method comprises the steps of (1) establishing a functional relation formula of the surface roughness Ra and a diffusion parameter sigma; (2) selecting at least 5 galvanized plates different in color intensity, respectively measuring the surface roughness Ra and the diffusion parameter sigma of each plate to obtain a formula determined by undetermined coefficients; (3) selecting the galvanized plates with normal surfaces, measuring the surface roughness Ra0, calculating the diffusion parameter sigma0 through the formula and using the diffusion parameter sigma0 as a reference; (4) measuring the surface roughness Ran of the galvanized plates having chromatic aberration and calculating the diffusion parameter sigman through the formula; (5) comparing the sigman with the sigma0, wherein the plates are brighter if a sigman-sigma0 numerical value is a positive number, the color and luster degree is higher if the value is larger, the plates are dimmer if the sigman-sigma0 numerical value is a negative number, and the color and luster degree is lower if the value is larger. The method utilizes online quantification of the surface color and luster degree of the galvanized plates to determine the chromatic aberration level of the surfaces of galvanized steel plates and is simple in operation, practical and high in working efficiency.