1. A texture filtering apparatus comprising: a first generating unit configured to generate first texture data having a size designated by a user or satisfying a condition designated by the user by using not less than second texture data acquired under different conditions or generated under different conditions; a second generating unit configured to generate texture data for filtering used for filtering by using the first texture data; and a filtering unit configured to perform filtering on the first texture data by using a designated filtering condition and the texture data for filtering.