Subspace Construction from Artificially Generated Images for Traffic Sign Recognition

Recognition technologies using digital cameras have gained considerable interest in recent years. However, even with the improvements of digital cameras, the quality of captured images often can be insufficient for the recognition in many practical cases. In order to recognize low-quality images, similarly degraded images should be used for training classifiers. This chapter presents a training method for the subspace method. It is named “Generative learning method,” since the training images are generated artificially from an original image. Conventional approaches used camera-captured images as training data, which required exhaustive collection of captured samples. The generative learning method, instead, allows to obtain these training images based on a small set of actual images. Since the training images need to be generated on the basis of actual degradation characteristics, the estimation step of the degradation characteristics is introduced. This framework is applied to traffic sign recognition that is one of the important tasks for driver support systems.