Image Overlay Text Detection Based on JPEG Truncation Error Analysis

This letter proposes a new algorithm for the detection and localization of overlay text in still images. The algorithm is based on the fact that the high-contrast edges in overlay text boundaries generate truncation error when subjected to JPEG compression. The regions containing high-contrast edges in a given test image are first identified using a discrete cosine transform (DCT) domain technique and a binary truncation error map is generated. The overlay text regions in the truncation error map are generally clustered and the cluster corresponding to a text line appears in a connected form. The initial detection is refined using connected component-based processing. Experimental results on a set of $300$ images taken from news videos show that the proposed method is effective in detection of overlay text with a good accuracy.