19. A learning apparatus for a pattern detector, which includes a plurality of weak classifiers and detects a specific pattern from input data by classifications of the plurality of weak classifiers, comprising: a model generation unit configured to generate a weak classifier model as a basis of a weak classifier based on a plurality of data for learning, in each of which whether or not the specific pattern is included is given; an update unit configured to update state parameters of a weak classifier generated based on the weak classifier model generated by the model generation unit until the weak classifier satisfies a predetermined performance; and a management unit configured to manage an update history of the state parameters of the weak classifier in each stage updated by the update unit, wherein the update unit selects and updates a state parameter of a stage to be updated of the weak classifier from the update history managed by the management unit based on a performance evaluation result of the weak classifier.
19. A learning apparatus for a pattern detector, which includes a plurality of weak classifiers and detects a specific pattern from input data by classifications of the plurality of weak classifiers, comprising: a model generation unit configured to generate a weak classifier model as a basis of a weak classifier based on a plurality of data for learning, in each of which whether or not the specific pattern is included is given; an update unit configured to update state parameters of a weak classifier generated based on the weak classifier model generated by the model generation unit until the weak classifier satisfies a predetermined performance; and a management unit configured to manage an update history of the state parameters of the weak classifier in each stage updated by the update unit, wherein the update unit selects and updates a state parameter of a stage to be updated of the weak classifier from the update history managed by the management unit based on a performance evaluation result of the weak classifier. 23. The apparatus according to claim 19 , wherein the update unit selects a state parameter of a stage to be updated of the weak classifier from the update history based on one of a degree of similarity with the weak classifier model generated by the model generation unit, a detection performance, and an arithmetic speed, or a calculation result of an evaluation function which includes these elements and is used to comprehensively evaluate a performance of the weak classifier, upon updating the state parameter of the weak classifier.