Earticle

The text localization and recognition in real time scene text images is still a big issue in current application. Mobile application and digitization in real world gives a vital and broad impact on real time scene text images. However, the efficiency of recognition rate depends upon the text localization, i.e., higher the purity of text background segmentation and decomposition, higher the rate of accuracy for the image recognition. In this paper, we present a new scene text detection algorithm based on Stroke detection and Hog Transform method. The method introduces an approach for character detection and recognition which combines the advantages of Hog Transform and Connected Component methods. Characters are detected and recognized on the basis of image regions which contain strokes of specific orientations in a specific relative position, where the strokes are efficiently detected by convolving the image gradient field with a set of oriented bar filters. The method was evaluated on a standard dataset consisting mostly real time images where it achieves state-of-the-art results in both text localization and recognition. The results clearly depict the higher bit of accuracy in terms of localization and recognition for a collected dataset.

Overlay text in video carries important semantic clues for video information retrieval and summarization. In this paper, we propose a robust method that is able to accurately locate text lines and extract text even in complex video scene. In the text localization stage, this paper adopts the method based on corner point. First, corner detection is used to extract corners as text features from video frames. Then multi-layer filtering mechanism (MLFM) is used to locate the text lines, which consists of corners clustering, corners horizontal projection, background filtering and heuristic rules. This MLFM can effectively remove the isolated corners, locate the text lines accurately and remove the background or pseudo text lines automatically. In the text extraction stage, this paper proposed a twice binarization method that combines with polarity judgment on image. The polarity judgment was used as a guide to adjust the first binarization threshold when we perform the first binarization. After the first binarization, a main proportion of the image has been processed, and the rest will be processed by the second binarization. Experimental results show that this approach can fast and robustly locate text lines and extract text in video even under complex background.

본 논문에서는 자연영상에 존재하는 문자들을 효율적으로 검출하기 위한 새로운 접근 방법을 제안한다. 빛 또는 조명의 영향에 의해 획득된 영상 내에 존재하는 반사성분은 문자 또는 관심객체들의 경계가 모호해 지거나 관심객체와 배경이 서로 혼합되었을 경우, 문자추출 및 인식을 함에 있어서 오류를 포함시킬 수 있다. 따라서 영상 내에 존재하는 반사성분을 제거하기 위해 먼저, 영상으로부터 Red컬러 성분에 해당하는 히스토그램에서 두개의 피크 점을 검출한다. 검출된 두 개의 피크 점들 간의 분포를 사용하여 노말 또는 편광 영상에 해당하는지를 판별한다. 노말 영상의 경우 부가적인 처리를 거치지 않고 문자영역을 검출하며 편광 영상인 경우 조명성분을 제거하기 위해 호모모픽 필터링 방법을 적용하여 반사성분에 해당하는 영역을 제거한다. 그리고 문자영역을 검출하기 위해 색 병합과 세일런스 맵을 이용하여 각각의 문자 후보영역을 결정한다. 마지막으로 두 후보영역을 이용하여 최종 문자영역을 검출한다.

This paper proposes a new approach to eliminate the reflectance component for the localization of text in natural scene images. Natural scene images normally have an illumination component as well as a reflectance component. It is well known that a reflectance component usually obstructs the task of detecting and recognizing objects like texts in the scene, since it blurs out an overall image. We have developed an approach that efficiently removes reflectance components while Preserving illumination components. We decided whether an input image hits Normal or Polarized for determining the light environment, using the histogram which consisted of a red component. In the normal image, we acquired the text region without additional processing. Otherwise we removed light reflecting from the object using homomorphic filtering in the polarized image. And then this decided the each text region based on the color merging technique and the Saliency Map. Finally, we localized text region on these two candidate regions.