An example of such a heuristic-based text detector can be seen in my previous blog post on Detecting machine-readable zones in passport images. Figure 1: Examples of natural scene images where text detection is challenging due to lighting conditions, image quality, and non-planar objects (Figure 1 of Mancas-Thillou and Gosselin).ĭetecting text in constrained, controlled environments can typically be accomplished by using heuristic-based approaches, such as exploiting gradient information or the fact that text is typically grouped into paragraphs and characters appear on a straight line.
