Document Dewarping with Control Points

From a single low resolution image, a real-time document image super-resolution algorithm is proposed to obtain high resolution document image with sharp text boundaries. First, a highly efficient document image matting algorithm based on local linear modeling is designed to decompose the input image into text, foreground and background layers, which contain the text edge information, the color information of the foreground and background respectively. Then the text layer is up-sampled with Teager filter to increase the sharpness of the text. For efficiency, the foreground and background layers are simply up-sampled through the bi-cubic interpolation. Finally, these three high resolution layers are composed to obtain the high-resolution image. Experiments on real scanned document images demonstrate the effectiveness of the proposed method in both visual perception and OCR performance

This paper presents a new algorithm to threshold document images. The proposed algorithm deal with complex background images, illumination and aspect variants, back-to-front interference, variation of brightness and different positioned shadows. The algorithm have two phases. The first one uses edge detection and morphological operations to identify the text on the image. The second phase uses the positions of the text to define the threshold value in an adaptive process. Our approach presents promising results in images with complex background released from the Document Image Binarization Contest (DIBCO) when compared with other literature and competition thresholding algorithms.

Portable spectroscopy for high throughput food authenticity screening: Advancements in technology and integration into digital traceability systems

The article discusses the use of digital aerial photography and aircraft laser scanning to assess the state of rice systems. An analysis of the state of affairs in rice growing shows that today there is not enough financial resources not only for the reconstruction and technical re-equipment of outdated elements of rice systems, updating technologies and equipment in accordance with the achievements of science and best practices, but also to maintain the existing technical level of the systems. The article presents the results of a study of planning technology options and the prospects for its improvement based on the introduction of laser control systems. Rational use of water, material and labor resources is the main reserve for increasing the efficiency of rice systems. The resource-saving potential contributes to the intensification of the production activities of water users. Rice is the most productive and most water-intensive crop. Rice cultivation in Russia was most widespread in the Kuban, occupying a technologically advanced position. Rice irrigation systems occupy once unproductive lands with a thin humus horizon, with a low humus content and unfavorable water-physical properties, prone to swimming and the formation of a surface soil crust. Research has shown that significant improvements in planning quality in the construction of rice paddies can be achieved with laser control systems. As part of the modern development of aerial survey work, a network of base stations, reference and control points is being created to conduct a technical survey of the structures of the rice system. Measurements are made using GNSS satellite measurements. The distance between base stations is no more than 60 km, between control points – no more than 20 km. At each 20-kilometer aerial survey site, it is necessary to provide four planned altitude landmarks and one control point. Identification marks and control points should be applied on the ground, the coordinates of these points should be determined by instrumental geodetic methods for conducting a technical survey of the structures of rice systems.

Several valuable heritage structures worldwide are in danger due to natural causes or human interferences. Therefore, a low-cost modeling technique is extremely important and widely needed for the preservation of heritage especially in poorer countries. This study evaluates the precision and accuracy of terrestrial photogrammetry via low-cost digital cameras to construct a 3-D model of an object. To obtain the goal, a building façade is imaged by employing two low-cost digital cameras, namely Canon and Pentax. The accuracy of the photogrammetric point clouds that are generated via the method is compared with a few natural control points collected via a laser total station. Cloud-to-cloud distance is computed for different 3-D models to investigate different variables such as camera type and control points. The results of the practical field experiment indicate that the mean differences between obtained 3-D models and reference points are in the range of 2.3–4.1 cm without using any control points. Using a few of the control points, the differences are improved such that they are between 1.4 and 1.6 cm. The comparisons indicate that the largest variances between the laser total station and photogrammetric outcomes occurred when the Pentax camera was used.

Mathematical formulation of unsmooth surfaces such as the physical earth poses several difficulties. To achieve an accurate formulation, each and every point of the surface must be defined, which is practically impossible. Therefore, in modelling such surfaces there is a need for an adequate number and distribution of reference points as well as an appropriate interpolation method. Working on computerised three-dimensional (3D) models, users can dynamically make various analyses on the surface, one of which is the volume calculation. The accuracy of the volume calculation depends on the appropriateness of the interpolation method used in creating 3D models. The present study, which aims to investigate the accuracy of the calculated volumes of objects with irregular structures, uses an artificial object with irregular form whose volume can be indirectly calculated. Using different interpolation methods on this artificial object through photogrammetrically measured reference points, 3D surface models were formed and volumes were calculated. A comparison between the measured and calculated volume figures revealed that the Inverse Distance Weighting (INDW), Nearest Neighbour (NENE) and Triangulation with Linear (TLIN) interpolation methods yielded more accurate results than the other methods. In order to investigate the volumetric accuracy, the same procedure was applied to a regular geometrically-shaped conical frustum and a pyramidal frustum with different numbers of faces, whose reference points on the surface were reproduced in accordance with mathematical rules. The volume of the pyramidal frustum which was obtained using different interpolation methods was then compared to that of the pyramidal frustum which was mathematically calculated and that of the conical frustum which was taken as the reference surface. The comparison demonstrated that the Data Metrics (DMET), INDW and Minimum Curvature (MCRV) interpolation methods yielded better results in terms of volumetric accuracy. Keywords: Interpolation methods, DTM, landform volume, volumetric accuracy.

Document image binarization plays an important role in image segmentation and its effect directly impacts on the quality of the OCR recognition system. However, binarization is difficult for camera-based document images with poor contrast or illumination. In this paper, we propose a binarization algorithm, called NFCM, for camera-based document image. NFCM, a local threshold method, is a combination of Niblack algorithm and FCM (Fuzzy C-Means) algorithm. It is good at not only preserving the character stokes, but also alleviating the ghost artifacts. Comparative experiments show that NFCM can obtain favorable results with respect to the OCR performance.

This paper presents a robust vision algorithm for tracking the boundary of an object with an arbitrary shape by using monocular image sequences. This method consists of a curve registration based optimization technique and a deformable contour model (snakes) for the global and the motion estimations, respectively. By combining techniques, we overcome, among other problems, inaccurate estimate of motion parameters in the curve registration method (which apparently only occur when a rigid or a flexible object is tracked), and the local position variation of the deformable contour model, variations, which are due to noisy images and/or complex backgrounds. The curve registration method uses an iterative algorithm to find the minimum normal distance between two curves, one before motion and the corresponding curve after it. Snakes overcome the limitation of the curve registration method, which suffers from the inaccuracy of motion models. We also propose an internal force, which increases robustness of the deformable contour to background noise. By using the refined snakes' control points, the global update of the previous curve is performed for the re-location of the registered curve. Additionally, we integrate the geometric invariant value of the boundary contour and the curve registration method to solve the occlusion problem in visual tracking. The proposed method is validated through experiments on real images.

During this decade, pixels have become mobile. Cell phones, PDAs, handheld gaming consoles and other similar devices start to have color displays by standard and color displays are hungry for high-quality graphics. QVGA and VGA display resolutions are common, requiring dedicated hardware for graphics acceleration. Color displays and open platforms also invite games and other applications, which build on the availability of robust graphics. Handheld graphics acceleration is close to its desktop and games console counterparts Ű with content running on an embedded version of OpenGL, the OpenGL ES 2.0, vertex and pixel shaders are a requirement. Floating-point accuracy, lots of texture surfaces, plenty of performance Ű handheld pixels are of good quality and there are lots of them. Handheld gaming drives the handheld 3D graphics performance, but unlike on desktops, vector graphics hardware acceleration will become an even widely spread requirement on new handheld platforms. Applications such as the device's main graphical user interface and interactive maps are driving these requirements. In addition to performance, a strong driver for vector graphics on handhelds is image quality.The first handheld devices, including cell phones, with dedicated 3D graphics accelerators have already hit the market. By 2010, a large number of new cell phones and PDAs will be enabled with hardware vector- and 3D graphics acceleration. The volume of graphics acceleration enabled silicon chips shipping for handheld devices is expected to be significantly higher than for desktop PCs and gaming consoles. This creates a lucrative platform for game and application developers who want to develop handheld content with high-quality graphics.As there are numerous different handheld devices, the industry is fighting against fragmentation Ű widely adopted platforms must be created to enable universal content development across a wide range of platforms and end devices Ű the platform race is already on.All in all, the industry is busy creating all the essential components to bring high-quality programmable pixels to handheld devices. Content developers are already up-to speed to provide winning content for these devices. All in all, the future of handheld pixels looks rosy!

Optimization and comparison of three spatial interpolation methods for electromagnetic levels in the AM band within an urban area

The current 2G and 3G network infrastructures were not originally designed with multimedia transmission in consideration. Unlike data transmission, multimedia has significantly different Quality of Service requirements. It requires significantly higher bandwidth in comparison with data transmission. Multimedia transmission over handheld devices (such as mobile phones) poses further challenges in maintaining a good Quality of Experience as wireless networks are inherently of low bandwidth and relatively unreliable. Handheld devices are resource constraint devices and therefore huge processing at the handheld devices may introduce delay in the multimedia reception. In this paper, we present an algorithm for bandwidth aggregation for multimedia transmission from a handheld device using the available bandwidth of other handheld devices. We use a distributed approach to play a non-zero sum game among the handheld devices to minimize the end-to-end delay and maximize the throughput. We incorporate a cooperative game to dynamically add or delete other handheld devices based on the requirements of the network. We validate our work and demonstrate its benefits.

Image processing is very much important area of research nowadays and is being taken interest deeply as the mobile phones and smart cameras are demands of the emerging global markets. Document image processing is the sub branch of it which includes processing the images of the paper may or may not be containing any write up or say textual contents, graphics, tables or any informative thing in form of written or printed stuff. Many a time’s we people are habituated to fold the document papers in our hands and put them in pocket or somewhere. If then we want them to be scanned or apply OCR (OPTICAL CHARACTER RECOGNITION) on them then we need to capture an image of such folded documents. For image acquisition there are many sources like digital cameras, mobile phone cameras, printers etc. are available around us. When we need to scan them to convert them into electronic form (to perform OCR on them), then the problems occur because the folded documents cannot be easily scanned as they have folds and due to such folds there are huge possibilities of shadows in fold parts which can distort the quality of the document as well as this may make the readability of the document poorer. In this paper, the authors have proposed an algorithm to straighten such folded document image to get accurate OCR results in accordance with least distortion in quality of the same. The derived method helps to straighten the uniform folds digitally. So that the processed document can be applied to get improved OCR results with improved in terms of accuracy.

In November 1968, a marine geodetic control point was established in the Pacific Ocean at a water depth of6,200 feet. The control point (reference point) consists of three underwater acoustic transponders, two of which are powered with lead-acid batteries and the third with an underwater radioisotope power source “URIPS” with a10- to20- year life expectancy. Four independent measuring techniques (LORAC airborne line-crossing, satellite, ship inertial, and acoustic techniques) were used to measure and determine the coordinates of the control point. Preliminary analysis of the acoustic and airborne data indicates that high accuracies can be achieved in the establishment of geodetic reference points at sea. Geodetic adjustment by the method of variation of coordinates yielded a standard point error of±50 to±66 feet in determining the unknown ship station. The original location of the ship station as determined by shipboard navigation equipment was off by about1,600 feet.

The mobile phone industry has experienced an explosive growth in recent years. Mobile phone subscriber numbers have passed the 1.6 billion mark at the end of 2004. The emerging markets such as China, India, and Brazil contribute this growth. In China, the number of mobile subscribers has already surpassed the number of fixed landline phone subscribers. In Korea, the number of mobile phone Internet subscribers is 34.53 million people or 72% of the population in June 2004 (APEC, 2005). Mobile e-commerce (m-commerce) makes business mobility a reality. Mobile users can access the Internet at anytime and anywhere with ubiquitous, inexpensive computing infrastructure. Mobile wireless services are ranging from mobile phone networks to wireless local area networks. The service provided by mobile phone systems has achieved huge success. Mobile phone users originate from all walks of life and include almost all age groups—from teenagers to retired people. It creates a new method of personal communication without location constraints. As telecommunication technologies are converging at fast speed. We will study mobile phone and personal digital assistant (PDA) related to mobile and wireless telecommunication. Hence, m-commerce is defined as electronic commerce carried out in handheld devices such as mobile phone and PDA through mobile and wireless telecommunication networks.

To solve the problem of low efficiency of fiducial markers detection and recognition due to the distortion of fiducial marker images caused by shooting angle and obliqued markers in practical applications, this paper proposes a method for registration and recognition of deformed fiducial markers, which combines two deep convolutional neural networks with the Perspective-n-Point (PnP) algorithm to estimate the 6DoF of the deformed ArUco markers. Firstly, ArUco is detected quickly and accurately through the improved U2Net; Secondly, the control points and reference points on deformed marker images are predicted, and the interpolation relationship between the predicted control points and reference points is then used to achieve deformation correction; Finally, the PnP algorithm is used for pose estimation. Through the comparative experimental evaluation on the self-collected dataset, the results have shown that the method proposed in this paper can detect and recognize the deformed ArUco markers with high accuracy and reliability under the complex scenes, and effectively improve the recognition rate of the deformed markers.