Showing papers on "Digital camera published in 2012"

Image Forgery Localization via Fine-Grained Analysis of CFA Artifacts

Abstract: In this paper, a forensic tool able to discriminate between original and forged regions in an image captured by a digital camera is presented. We make the assumption that the image is acquired using a Color Filter Array, and that tampering removes the artifacts due to the demosaicking algorithm. The proposed method is based on a new feature measuring the presence of demosaicking artifacts at a local level, and on a new statistical model allowing to derive the tampering probability of each 2 × 2 image block without requiring to know a priori the position of the forged region. Experimental results on different cameras equipped with different demosaicking algorithms demonstrate both the validity of the theoretical model and the effectiveness of our scheme.

Multiple exposure high dynamic range image capture

Abstract: Techniques for creating a High Dynamic Range (HDR) image within a consumer grade digital camera from a series of images of a scene captured at different exposure levels, and displaying the HDR image on the camera's built-in display, are provided. The approach employs mixing images of the series to incorporate both scene shadow and highlight details, and the removing of “ghost” image artifacts appearing in the mixed HDR image resulting from movement in the scene over the time the series images are captured. The low computational resource utilization of the present invention's image mixing and ghost removal processing operations, along with the present invention's ability to commence image mixing and ghost removal prior to the acquisition of all series images, can significantly reduce the time required to generate and display a tone mapped HDR image.

Compressive Light Field Sensing

Abstract: We propose a novel design for light field image acquisition based on compressive sensing principles By placing a randomly coded mask at the aperture of a camera, incoherent measurements of the light passing through different parts of the lens are encoded in the captured images Each captured image is a random linear combination of different angular views of a scene The encoded images are then used to recover the original light field image via a novel Bayesian reconstruction algorithm Using the principles of compressive sensing, we show that light field images with a large number of angular views can be recovered from only a few acquisitions Moreover, the proposed acquisition and recovery method provides light field images with high spatial resolution and signal-to-noise-ratio, and therefore is not affected by limitations common to existing light field camera designs We present a prototype camera design based on the proposed framework by modifying a regular digital camera Finally, we demonstrate the effectiveness of the proposed system using experimental results with both synthetic and real images

Dual-spectrum digital imaging welding helmet

Abstract: Arc welding systems, methods, and apparatus that provide dual-spectrum, real-time viewable, enhanced user-discrimination between arc welding characteristics during an arc welding process. Welding headgear is configured to shield a user from harmful radiation and to include a digital camera or cameras to provide dual-spectrum (i.e., both visible spectrum and infrared spectrum) real-time digital video image frames. The welding headgear is also configured with an optical display assembly for displaying real-time digital video image frames to the user while wearing the headgear during an arc welding process. Image processing is performed on the visible and infrared spectrum video image frames to generate dual-spectrum video image frames providing an integrated and optimized view of both the visible and thermal characteristics of the arc welding process which can be viewed by the user on the optical display assembly in real time.

Digital camera simulation.

Abstract: We describe a simulation of the complete image processing pipeline of a digital camera, beginning with a radiometric description of the scene captured by the camera and ending with a radiometric description of the image rendered on a display. We show that there is a good correspondence between measured and simulated sensor performance. Through the use of simulation, we can quantify the effects of individual digital camera components on system performance and image quality. This computational approach can be helpful for both camera design and image quality assessment.

Image sensing and printing device

Abstract: An image sensing and printing digital camera device includes a housing defining a slot for receiving a printed instruction card having printed thereon an array of dots representing a programming script, the housing further storing therein a roll of print media; an area image sensor for sensing an image and generating pixel data representing the image; a linear image sensor for scanning the array of dots on the card and converting the array of dots into a data signal; a microcontroller provided in the housing, the microcontroller for decoding the data signal into the programming script and applying the programming script on the pixel data; and a printing mechanism for printing the pixel data, having applied thereto the programming script, on the roll of print media. The microcontroller integrates on a single chip a VLIW processor, a printhead interface, and an output buffer effecting communication between the VLIW processor and the printhead interface.

The systematic error in digital image correlation induced by self-heating of a digital camera

Abstract: The systematic strain measurement error in digital image correlation (DIC) induced by self-heating of digital CCD and CMOS cameras was extensively studied, and an experimental and data analysis procedure has been proposed and two parameters have been suggested to examine and evaluate this. Six digital cameras of four different types were tested to define the strain errors, and it was found that each camera needed between 1 and 2 h to reach a stable heat balance, with a measured temperature increase of around 10 ?C. During the temperature increase, the virtual image expansion will cause a 70?230 ?? strain error in the DIC measurement, which is large enough to be noticed in most DIC experiments and hence should be eliminated.

View Planning for Multi-View Stereo 3D Reconstruction Using an Autonomous Multicopter

Abstract: Multi-view stereo algorithms are an attractive technique for the digital reconstruction of outdoor sites. Concerning the data acquisition process a vertical take off and landing UAV carrying a digital camera is a suitable platform in terms of mobility and flexibility in viewpoint placement. We introduce an automated UAV based data acquisition and outdoor site reconstruction system. A special focus is set on the problem of model based view planning using a coarse digital surface model (DSM) with minimal data preprocessing. The developed view planning heuristic considers a coverage, a maximum view angle and an overlapping constraint imposed by multi-view stereo reconstruction techniques. The time complexity of the algorithm is linear with respect to the size of the area of interest. We demonstrate the efficiency of the entire system in two scenarios, a building and a hillside.

Construction of an inexpensive, hand-held fundus camera through modification of a consumer "point-and-shoot" camera.

Abstract: PURPOSE To construct a low-cost, easy-to-use, high-image-quality mydriatic fundus camera with "point-and-shoot" operation, and to evaluate the efficacy of this camera to accurately document retinal disease METHODS A prototype portable fundus camera was designed by interfacing a novel optical module with a Panasonic Lumix G2 consumer camera Low-cost, commercially available optics were used to create even illumination of the fundus, providing a 50° retinal field of view A comparative study assessing the image quality of the prototype camera against a traditional tabletop fundus camera was conducted under an Institutional Review Board (IRB)-approved study RESULTS A stand-alone, mydriatic camera prototype was successfully developed at a parts cost of less than $1000 The prototype camera was capable of operating in a point-and-shoot manner with automated image focusing and exposure, and the image quality of fundus photos was comparable to that of existing commercial cameras Pathology related to both nonproliferative and proliferative diabetic retinopathy and age-related macular degeneration was easily identified from fundus images obtained from the low-cost camera CONCLUSIONS Early prototype development and clinical testing have shown that a consumer digital camera can be inexpensively modified to image the fundus with professional diagnostic quality The combination of low cost, portability, point-and-shoot operation, and high image quality provides a foundational platform on which one can design an accessible fundus camera to screen for eye disease

Spatially incoherent single channel digital Fourier holography

Abstract: We present a new method for recording digital Fourier holograms under incoherent illumination. A single exposure recorded by a digital camera is sufficient to record a real-valued hologram that encodes the complete three-dimensional properties of an object.

Camera system comprising color display and processor for decoding data blocks in printed coding pattern

Abstract: A camera system including: a substrate having a coding pattern printed thereon and a handheld digital camera device. The camera device includes: a digital camera unit having a first image sensor for capturing images and a color display for displaying captured images to a user; and an integral processor configured for: controlling operation of the first image sensor and color display; decoding an imaged coding pattern printed on a substrate; and performing an action in the handheld digital camera device based on the decoded coding pattern. The decoding includes the steps of: identifying a data block in the imaged coding pattern; decoding a control block to determine the size of data to be extracted from a data area; and decoding the coding pattern contained in ae data area of the data block.

The procedure of a camera calibration using Camera Calibration Toolbox for MATLAB

Abstract: This paper describes the calibration procedure of a CCD digital camera based on the perspective projection method. The idea of this method is to calibrate the camera in order to extract precise three dimensional information from the images so that they can be used for the computer vision and similar applications which take the images acquired from the camera as an input. The image capturing process reduces the dimensions of data from three to two. The camera calibration procedure determines which light source is associated with each pixel on the resulting image. Since the camera used in the process is a complex CCD camera, errors resulting from the misaligned lenses and deformations in their structures result in more complex distortions in the acquired image. In order to associate the points in the cameras image space with the locations in a 3D world space the camera projection matrix consisting of the estimated intrinsic and extrinsic parametars is calculated. The calibration process is comprised of capturing calibration images and processing them in order to get the intrinsic and extrinsic camera parameters. The results of the calibration are tested using the test images captured with the same camera. The calibration process was implemented using a MATLAB software package.

Fast and Accurate Method for Leaf Area Measurement

Abstract: Leaf area plays an important role in plant growth analysis and photosynthesis. Traditionally leaf area is measured by regression equitation, grid count method, gravimetric method and planimeter. In this paper a simple, fast and accurate algorithm for leaf area measurement using image processing is implemented. Image is acquired using digital camera and stored in JPEG format. RGB image is color transformed into CIELAB color space. Color transformed image is segmented using threshold technique. Threshold is calculated using OTSU‟s method. Holes in leaf region are filled using region filling technique. Number of pixels in square object and leaf region are calculated and leaf area is measured by number of pixels statistics. Accuracy of algorithm is above 99% which is confirmed by comparing the results of proposed algorithm with grid count method. General Terms Digital Image Processing, Image Segmentation.

Image pickup apparatus, image pickup method and recording device recording image processing program

Abstract: A digital camera has an image pickup unit which can obtain a set of plural input images with different exposure amounts by photographing the same subject; an image synthesizing unit which creates a synthesized image from the set of plural input images; a live-view image output unit which outputs a live-view image on the basis of the synthesized image obtained by synthesizing a set of n pieces of (n is an integer not less than 2) input images with different exposure amounts obtained from the photographing unit during a view display operation; and a recorded image creating unit which creates an image for recording on the basis of the synthesized image obtained by synthesizing a set of m pieces of (m is an integer not less than 2) input images with different exposure amounts obtained from the image pickup unit during main photographing in the image synthesizing unit.

Palmprint Recognition across Different Devices

Abstract: In this paper, the problem of Palmprint Recognition Across Different Devices (PRADD) is investigated, which has not been well studied so far. Since there is no publicly available PRADD image database, we created a non-contact PRADD image database containing 12,000 grayscale captured from 100 subjects using three devices, i.e., one digital camera and two smart-phones. Due to the non-contact image acquisition used, rotation and scale changes between different images captured from a same palm are inevitable. We propose a robust method to calculate the palm width, which can be effectively used for scale normalization of palmprints. On this PRADD image database, we evaluate the recognition performance of three different methods, i.e., subspace learning method, correlation method, and orientation coding based method, respectively. Experiments results show that orientation coding based methods achieved promising recognition performance for PRADD.

Significance level of image enhancement techniques for underwater images

Abstract: Underwater imaging is quite a challenging in the area of photography especially for low resolution and ordinary digital camera. There are a few problems occur in underwater images such as limited range visibility, low contrast, non uniform lighting, blurring, bright artefacts, color diminished and noise. This paper concentrates on color diminished. Significant application of standard computer vision techniques to underwater imaging is required in dealing with the said problems. Both manual and auto level techniques are used to record the mean values of the stretched histogram. The objective of the paper is to identify which technique is more significant in terms of color correction. It is hoped that the finding will benefit to non divers to visualize the underwater as the real underwater world.

Digital camera calibration using images taken from an unmanned aerial vehicle

Abstract: For calibrating the camera, an accurate determination of the interior orientation parameters is needed. For more accurate results, the calibration images should be taken under conditions that are similar to the field samples. The aim of this work is the establishment of an efficient and accurate digital camera calibration method to be used in particular working conditions, as it can be found with our UAV (Unmanned Aerial Vehicle) photogrammetric projects. The UAV used in this work was md4-200 modelled by Microdrones. The microdrone is also equipped with a standard digital non- metric camera, the Pentax Optio A40 camera. To find out the interior orientation parameters of the digital camera, two calibration methods were done. A lab calibration based on a flat pattern and a field calibration were fulfilled. To carry out the calibration, Photomodeler Scanner software was used in both cases. The lab calibration process was completely automatic using a calibration grid. The focal length was fixed at widest angle and the network included a total of twelve images with± 90o roll angles. In order to develop the field calibration, a flight plan was programmed including a total of twelve images. In the same way as in the lab calibration, the focal length was fixed at widest angle. The field test used in the study was a flat surface located on the University of Almeria campus and a set of 67 target points were placed. The calibration field area was 25 × 25 m approximately and the altitude flight over ground was 50 m. After the software processing, the camera calibration parameter values were obtained. The paper presents the process, the results and the accuracy of these calibration methods. The field calibration method reduced the final total error obtained in the previous lab calibration. Furthermore the overall RMSs obtained from both methods are similar. Therefore we will apply the field calibration results to all our photogrammetric projects in which the flight high will be close to 50 m.

Digital camera with light splitter

Abstract: A digital camera component is described that has a light splitter cube having an entrance face to receive incident light from a camera scene. The cube splits the incident light into first, second, and third color components that emerge from the cube through a first face, a second face, and a third face of the cube, respectively. First, second, and third image sensors are provided, each being positioned to receive a respective one of the color components that emerge from the first, second, and third faces of the cube. Other embodiments are also described and claimed.

Digital 3d camera using periodic illumination

Abstract: A method of operating a digital camera, includes providing a digital camera, the digital camera including a capture lens, an image sensor, a projector and a processor; using the projector to illuminate one or more objects with a sequence of patterns; and capturing a first sequence of digital images of the illuminated objects including the reflected patterns that have depth information. The method further includes using the processor to analyze the first sequence of digital images including the depth information to construct a second, 3D digital image of the objects; capturing a second 2D digital image of the objects and the remainder of the scene without the reflected patterns, and using the processor to combine the 2D and 3D digital images to produce a modified digital image of the illuminated objects and the remainder of the scene.

Open Set Source Camera Attribution

Abstract: Similar to ballistic tests in which we match a gun to its bullets, we can identify a given digital camera that acquired an image under investigation. In this paper, we discuss a method for identifying whether or not an image was captured by a specific digital camera. The method relies on noise residual features related to the images under investigation. Our approach considers an ``open set" recognition scenario, under which we can not rely on the assumption of full access to all of the potential source cameras. This is the only scenario investigators are faced with in the real world. In this case, we model the decision space to take advantage of a few known cameras and carve the decision boundaries to decrease false matches increasing the reliability of image source attribution as an aid for digital forensics in the court of law. This approach performs favorably vs. the state-of-the-art.

Position and Orientation Determination in 6-DOF

Abstract: A method for a six degree of freedom position and orientation determination of a three dimensional known shape in a scenery, by taking a range image by means of a range imaging camera and taking a visual picture by means of a digital camera. The range imaging camera comprises a range image module having a sensor array with a first number of pixels, wherein for each of the first pixels range information from the sensor to a point of the scenery is determined, resulting in a 3D cluster of points. The digital camera comprises an image sensor having a second number of pixels, resulting in a 2D picture. The relation of the first and the second pixels fields of view is known. The method comprises a geometrically fitting of a stored 3D digital representation of the known shape in a virtual space to match with the reproduction of the known object in the 2D picture and the 3D cluster of points and determining the six degree of freedom position and orientation of the known shape in the scenery according to the virtual match.

Image processing apparatus and method of controlling the same

Abstract: An image processing apparatus such as a digital camera and a method of controlling the same is provided. In one embodiment, the digital camera generates an HDR image by combining two of a plurality of images to be combined for normal HDR processing. Before image combining operation, the digital camera converts the tone characteristics of at least one of the two images so as to assign more tone values to a tone area of an entire tone area of the HDR image which is not properly covered by either of the two images than before conversion.

System for presenting high-interest-level images

Abstract: A system comprising an image display; a digital camera positioned to capture images of persons viewing the image display; and a memory system storing instructions configured to cause a data processing system to implement a method for presenting digital images having a high interest level to a particular person selected from a set of candidate digital images. The method includes using the digital camera to capture an image including a particular person positioned to view the image display. The candidate digital images are analyzed to designate one or more image elements, and familiarity levels of the designated image elements to the particular person are determined. For each candidate digital image, an associated interest level to the particular person is determined responsive to the determined familiarity levels. One or more of the candidate digital images are selected based on the determined interest levels and are presented to the particular person.

Semantic image segmentation using visible and near-infrared channels

Abstract: Recent progress in computational photography has shown that we can acquire physical information beyond visible (RGB) image representations. In particular, we can acquire near-infrared (NIR) cues with only slight modification to any standard digital camera. In this paper, we study whether this extra channel can improve semantic image segmentation. Based on a state-of-the-art segmentation framework and a novel manually segmented image database that contains 4-channel images (RGB+NIR), we study how to best incorporate the specific characteristics of the NIR response. We show that it leads to improved performances for 7 classes out of 10 in the proposed dataset and discuss the results with respect to the physical properties of the NIR response.

User interface for a digital camera

Abstract: The present disclosure provides a user interface for a digital camera such as a digital camera built into a smartphone or other multipurpose portable electronic device. The user interface simultaneously displays an electronic viewfinder image and at least one other image such as a previously captured image. The previously captured image is located within the electronic viewfinder image. Designated input causes the previously captured image to be enlarged from an initial size to an enlarged size.

Measurement of wide frequency range structural microvibrations with a pocket digital camera and sub-pixel techniques

Abstract: Analysis of vibrations and displacements is a hot topic in structural engineering. Although there is a wide variety of methods for vibration analysis, direct measurement of displacements in the mid and high frequency range is not well solved and accurate devices tend to be very expensive. Low-cost systems can be achieved by applying adequate image processing algorithms. In this paper, we propose the use of a commercial pocket digital camera, which is able to register more than 420 frames per second (fps) at low resolution, for accurate measuring of small vibrations and displacements. The method is based on tracking elliptical targets with sub-pixel accuracy. Our proposal is demonstrated at a 10 m distance with a spatial resolution of 0.15 mm. A practical application over a simple structure is given, and the main parameters of an attenuated movement of a steel column after an impulsive impact are determined with a spatial accuracy of 4 µm.

Method and apparatus for capturing images

Abstract: According to one aspect of the inventive concept there is provided a method of capturing images using a camera. The method comprises analyzing a view depicted by the digital camera and determining, based on the analysis, a subset of configurations of the digital camera. The method further comprises capturing, in response to a detection of an image capturing command at the camera, a set of at least two images using at least two different configurations of said subset of configurations.