Surface characteristics evaluation method, surface characteristics evaluation apparatus, and surface characteristics evaluation program

A surface characteristics evaluation apparatus for evaluating a surface characteristic of a painted surface including a glittering material, comprising:

• a light source to emit light onto the painted surface;
• an image capturer configured to capture an image of the painted surface onto which the light is emitted;
• a mover configured to move a sample having the painted surface in a certain direction;
• a rotator configured to rotate at least one of the light source and the image capturer;
• multi-angle condition image acquisition circuitry configured to acquire a multi-angle condition image including multi-angle conditions in a continuous manner by performing an image-capturing process to capture how a reflection condition of the painted surface changes when the light source emits the light onto the painted surface and the rotating device rotates at least one of the light source and the image capturer, the image-capturing process being performed by the image capturer while the sample is moved in a certain direction;
• in-plane chromaticity distribution acquisition circuitry configured to acquire an in-plane chromaticity distribution of the painted surface from the multi-angle condition image acquired by the multi-angle condition image acquisition circuitry;
• and
• surface characteristics evaluation circuitry configured to calculate surface characteristics evaluation values of the multi-angle conditions, on the basis of the in-plane chromaticity distribution acquired by the in-plane chromaticity distribution acquisition circuitry;
• spatial-frequency characteristics calculation circuitry configured to calculate spatial-frequency characteristics upon dividing the multi-angle condition image according to the respective multi-angle conditions, on the basis of an amount of change in the in-plane chromaticity distribution acquired by the in-plane chromaticity distribution acquisition circuitry;
• and
• integrated value acquisition circuitry configured to calculate an integrated value by integrating the spatial-frequency characteristics,
• wherein the surface characteristics evaluation circuitry calculates the surface characteristics evaluation values on the basis of the integrated value calculated by the integrated value acquisition circuitry, and
• wherein the surface characteristics evaluation apparatus further comprises:
• correction circuitry configured to correct, with a reflection intensity of the glittering material, the integrated value calculated by the integrated value acquisition circuitry,
• wherein the surface characteristics evaluation circuitry calculates the surface characteristics evaluation values using the integrated value corrected by the correction circuitry.

A non-transitory computer readable medium including a surface characteristics evaluation program for evaluating a surface characteristic of a painted surface including a glittering material, the surface characteristics evaluation program causing a computer to execute:

• a multi-angle condition image acquisition function for acquiring a multi-angle condition image including multi-angle conditions in a continuous manner by performing an image-capturing process to capture how a reflection condition of the painted surface changes when rotating at least one of a light source emitting light onto the painted surface and an image capturer capturing images of the painted surface onto which the light is emitted, the image-capturing process being performed by the image capturer while a sample having the painted surface is moved in a certain direction;
• an in-plane chromaticity distribution acquisition function for acquiring an in-plane chromaticity distribution of the painted surface from the multi-angle condition image acquired by the multi-angle condition image acquisition function;
• and
• a surface characteristics evaluation function for calculating surface characteristics evaluation values of the multi-angle conditions, on the basis of the in-plane chromaticity distribution acquired by the in-plane chromaticity distribution acquisition function;
• a spatial-frequency characteristics calculation function of calculating spatial-frequency characteristics upon dividing the multi-angle condition image according to the respective multi-angle conditions, on the basis of an amount of change in the in-plane chromaticity distribution acquired in the in-plane chromaticity distribution acquisition function;
• and
• an integrated value acquisition function of calculating an integrated value by integrating the spatial-frequency characteristics,
• wherein in the surface characteristics evaluation function, the surface characteristics evaluation values are calculated on the basis of the integrated value calculated in the integrated value acquisition function, and
• wherein the program further causes the computer to execute:
• a correction function of correcting, with a reflection intensity of the glittering material, the integrated value calculated in the integrated value acquisition function,
• wherein in the surface characteristics evaluation function, the surface characteristics evaluation values are calculated by using the integrated value corrected in the correction function.