Three-stage binarization of color document images based on discrete wavelet transform and generative adversarial networks

The efficient segmentation of foreground text information from the background in degraded color document images is a critical challenge in the preservation of ancient manuscripts. The imperfect preservation of ancient manuscripts over time has led to various types of degradation, such as staining, yellowing, and ink seepage, significantly affecting image binarization results. This work proposes a three-stage method using Generative Adversarial Networks (GAN) for enhancing and binarizing degraded color document images through Discrete Wavelet Transform (DWT). Stage-1 involves applying DWT and retaining the Low-Low (LL) subband images for image enhancement. In Stage-2, the original input image is divided into four single-channel images (Red, Green, Blue, and Gray), and each is trained with independent adversarial networks to extract color foreground information. In Stage-3, the output image from Stage-2 and the original input image are used to train independent adversarial networks for document binarization, enabling the integration of global and local features. The experimental results demonstrate that our proposed method outperforms other classic and state-of-the-art (SOTA) methods on the Document Image Binarization Contest (DIBCO) datasets. We have released our implementation code at https://github.com/abcpp12383/ThreeStageBinarization.