An apparatus for enhancing training data includes a memory having a program stored thereon. The apparatus also includes a processor coupled to the memory and configured to execute the program. The processor is configured to generate a plurality of virtual images based on a real image. The processor is also configured to generate, based on respective levels of similarity between the real image and virtual images among the plurality of virtual images, a golden pair that pairs the real image with a virtual image among the plurality of virtual images. The processor is further configured to perform domain adaptation training on the real image and the virtual image that is paired with the real image.