1. An object recognition apparatus comprising: an obtaining unit configured to successively obtain images; an extraction unit configured to extract a partial region from an image obtained by the obtaining unit and extract a feature amount from the partial region; a recognition unit configured to recognize whether the partial region is a target object based on the extracted feature amount and one of a first recognition model and a second recognition model, the first recognition model including a feature amount of a positive example indicating the target object and a feature amount of a negative example indicating a background of the target object, and the second recognition model including a feature amount of the positive example; an updating unit configured to, in accordance with a result of the recognition, update the first recognition model by adding the extracted feature amount; and an output unit configured to output an object region recognized as being the target object, wherein the recognition unit performs recognition based on the first recognition model if the object region was output for a previous image obtained by the obtaining unit, and performs recognition based on the second recognition model if the object region was not output for the previous image.