A study about the reconstruction of remote, low resolution mobile captured text images for OCR

With the burst of low-cost and versatile mobile phones, people have more choices to digitize papers simply by capturing the text images of interest and put them through Optical Character Recognition (OCR) systems. However, the task is much more challenging when it comes to the issue of recognition of camera-based text images taken at remote distances. Those images, which often come up in small font and low resolution texts, results in poor readability in OCR. This paper presents a preliminary study on the human eye´s perception of English document images, taken by mobile phone at various distances. In addition, a text enhancement technique using the combination of power-law transformation and morphological bottom hat filtering, following by morphological reconstruction and interpolation is also addressed. The results achieve an improved performance in OCR recognition rate.