Capturing book images is more convenient with a mobile phone camera than with more specialized flat-bed scanners or 3D capture devices. We built an application for the iPhone 4S that captures a sequence of hi-res (8 MP) images of a page spread as the user sweeps the device across the book. To do the 3D dewarping, we implemented two algorithms: optical flow (OF) and structure from motion (SfM). ...

A method for the rectification of figures and photos in printed documents using a single camera-captured image. The algorithm requires a bounding box for the objects in a single-view image. On receiving the bounding box, the desired image can be cropped for further processing. The main feature of segmentation method is that, it exploits the properties of printed figures to detect the boundaries...

Cone photoreceptors in the living human eye have recently been imaged with micron-scale resolution in all three spatial dimensions using adaptive optics optical coherence tomography. While these advances have allowed non-invasive study of the three-dimensional structure of living human cones, studies of their function and physiology are still hampered by the difficulties to monitor the same cel...

Curled textlines segmentation is a necessary initial step for the hand-held camera-captured document image processing. Curled textlines information is often used as an intermediate step for camera-captured document image dewarping. Curled textlines information can also be used for other camera-based document image processing tasks, like layout analysis etc. So far no work has been done for the ...

Camera Based Document Analysis (CBDA) is an emerging field in computer vision and pattern recognition. In recent days, cameras are moulded with several items of additional equipment. Thus, they play a vital role in the replacement of scanners with hand-held imaging devices (HIDs) like digital cameras, mobile phones and gaming devices. Warping is a common appearance in camera captured document i...

Many algorithms to remove distortion from document images have be proposed in recent years, but so far there is no reliable method for comparing their performance. In this paper we propose a collection of methods to measure the quality of such restoration algorithms for document image which show a non-linear distortion due to perspective or page curl. For the result from these measurement to be...

Major challenges in camera-base document analysis are dealing with uneven shadows, high degree of curl and perspective distortions. In CBDAR 2007, we introduced the first dataset (DFKI-I) of camera-captured document images in conjunction with a page dewarping contest. One of the main limitations of this dataset is that it contains images only from technical books with simple layouts and moderat...

The development of Doppler Global Velocimetry as a flow diagnostic measurement sy s t em nece s s i t a t ed seve ra l innova t i ons to so l ve problems found during wind tunnel testing. These innovations ranged from ratioing a data image with a reference image to remove scattered light variations, dewarping the images to remove optical distortions, and to the use of virtual wind tunnels creat...

Binarization is an important preprocessing step in several document image processing tasks. Nowadays handheld camera devices are in widespread use, that allow fast and flexible document image capturing. But, they may produce degraded grayscale image, especially due to bad shading or non-uniform illumination. State-of-the-art binarization techniques, which are designed for scanned images, do not...

Abstract Document images captured by camera often suffer from warping and distortions because of the bounded volumes and complex environment light source. These effects not only reduce the document readability but also the OCR recognition performance. In this paper, we propose a method to combine non-linear and linear compensation for correcting distortions of document images. First, due to the...