1. A combing artifacts detection apparatus comprising: a feature-value calculating unit that calculates a feature value from an input image; a film-mode detecting unit that detects a film mode by using the feature value; a pixel-difference calculating unit that calculates a pixel difference between fields by using 2:3 pulldown sequence detection information and input-image combination information that are results of the film mode detection; a luminance-variation determining unit that determines luminance variation based on a calculation result of the pixel-difference calculating unit; a combing artifacts-candidate detecting unit that detects a combing artifacts candidate per line based on a determination result of the luminance-variation determining unit; and a combing artifacts determining unit that determines whether a combing artifacts occurs for each image based on a detection result of the combing artifacts-candidate detecting unit.