Proposal of the hybrid spectral gradient method to extract character/text regions from general scene images

We propose a spectral gradient method that is a novel method to extract character/text regions from general scene images. We obtain the distribution of the degree of likelihood of character/text regions by calculating the spatial variation of texture. We evaluate the texture variation by the gradient of local spatial spectra. A characteristic Fourier transform process, named hybrid spectral gradient method, is also developed to achieve a high extraction performance. This method is based on human foveation and can be applied for a wide range of languages and letters.