Showing papers on "Digital camera published in 2009"

Camera Interface in a Portable Handheld Electronic Device

Abstract: In accordance with some embodiments, a method is performed at a handheld electronic device having a built-in digital camera and a touch sensitive screen. The method includes detecting a multi-finger gesture on the touch sensitive screen, wherein the touch sensitive screen is serving as part of an electronic viewfinder of the camera; storing coordinates of a location corresponding to the detected multi-finger gesture; translating the stored coordinates to a selected area of an image that is captured by the camera and that is being displayed on the touch sensitive screen; contracting or expanding the selected area in response to the user's fingers undergoing a pinching movement or a spreading movement, respectively, while the detected multi-finger gesture remains in contact with the touch sensitive screen; and applying an automatic image capture parameter adjustment process that gives priority to the selected area.

Camera adapter based optical imaging apparatus

Abstract: The invention describes several embodiments of an adapter which can make use of the devices in any commercially available digital cameras to transform the digital camera into a fundus camera for inspecting the back of the eye, or into a microscope. The camera adapter is adapted to be placed between the camera device and the object. The devices in the camera being used are at least its optical source, photodetector sensor, memory, shutter and autofocus. Means in the adapter are provided to employ these devices and allow camera to operate its autofocus capability and its different color sensors. Methods of investigation of an object are also presented of using the adapter to transform the camera into an imaging instrument, where the effect of adjustments of elements inside the adapter are guided by the displaying screen of the camera.

High spatial resolution data acquisition for the geosciences: kite aerial photography

Abstract: This paper highlights the requirement for very high resolution (<0·25 m) elevation data for quantitative and qualitative morphometric analyses. Traditional techniques for high resolution data capture (e.g. airborne, heliborne) are prohibitively expensive for small studies and therefore a kite-based platform was developed, in conjunction with a consumer non-metric digital camera, for data capture. The combination of kite and digital camera is more generally termed kite aerial photography (KAP). The accuracy of data derived by digital photogrammetry and imagery acquired using a kite based non-metric camera is assessed by three experiments: one on smooth terrain, one on tor terrain and one on a glaciofluvial esker. Ground control targets were surveyed at all three sites, with the imagery subsequently processed using the Leica Photogrammetry Suite. The results demonstrate that the method can extract a high number of sampling points at high accuracy, provided that there is suitable image texture across the site. However, final judgment concerning the suitability of derived data is dependent upon an understanding of measurement variability and user quantification of acceptable accuracy. Copyright © 2008 John Wiley & Sons, Ltd.

Device case with optical lenses

Abstract: A carrying case for a portable electronic device such as a digital music player or mobile telephone having a digital camera includes a lens for modifying an optical input of the digital camera. The lens is positioned on the carrying case to correspond to a location of an input lens of the digital camera when the device is held within the case such that the camera can be used when the device is held by the carrying case. A plurality of lens of preferably mounted on a rotating disc so that a user can select a particular lens having a desired optical effect. Alternatively, a socket can be used to selectively mount a desired lens from a set of lenses. An illuminating LED may also be included on the case exterior to provide a flash for the camera.

Review of three-dimensional holographic imaging by multiple-viewpoint-projection based methods

Abstract: Methods of generating multiple viewpoint projection holograms of three-dimensional (3-D) realistic objects illuminated by incoherent white light are reviewed in this paper. Using these methods, it is possible to obtain holograms with a simple digital camera, operating in regular light conditions. Thus, most disadvantages characterizing conventional digital holography, namely the need for a powerful, highly coherent laser and extreme stability of the optical system, are avoided. The proposed holographic processes are composed of two stages. In the first stage, regular intensity-based images of the 3-D scene are captured from multiple points of view by a simple digital camera. In the second stage, the acquired projections are digitally processed to yield the complex digital hologram of the 3-D scene, where no interference is involved in the process. For highly reflecting 3-D objects, the resulting hologram is equivalent to an optical hologram of the objects recorded from the central point of view. We first review various methods to acquire the multiple viewpoint projections. These include the use of a microlens array and a macrolens array, as well as digitally generated projections that are not acquired optically. Next, we show how to digitally process the acquired projections to Fourier, Fresnel, and image holograms. Additionally, to obtain certain advantages over the known types of holograms, the proposed hybrid optical-digital process can yield novel types of holograms such as the modified Fresnel hologram and the protected correlation hologram. The prospective goal of these methods is to facilitate the design of a simple and portable digital holographic camera that can be useful for a variety of practical applications, including 3-D video acquisition and various types of biomedical imaging. We review several of these applications to signify the advantages of multiple viewpoint projection holography.

Automatic content tagging, such as tagging digital images via a wireless cellular network using metadata and facial recognition

Abstract: Described in detail herein are systems and methods for automatically generating tags for digital content, such as digital images from a digital camera or camcorder. Further, the system can automatically determine who or what may be in digital content. Further details and features are described herein.

System and method for obtaining georeferenced mapping data

Abstract: A system and method for acquiring spatial mapping information of surface data points defining a region unable to receive effective GPS signals, such as the interior of a building, includes an IMU for dynamically determining geographical positions relative to at least one fixed reference point, a LIDAR or camera for determining range of the IMU to each surface data point, and a processor to determine position data for each surface data point relative to the at least one reference point. A digital camera obtains characteristic image data, including color data, of the surface data points, and the processor correlates the position data and image data for the surface data points to create an image of the region.

Highspeed image selecting method and digital camera having highspeed image selecting function

Abstract: In a digital camera operation method, photographic images are taken with the camera and a corresponding compressed high resolution image and also a corresponding lower resolution image is stored for each. A fast display mode of the camera sequentially displays individual lower resolution display images, using the data of one of the lower resolution images. A normal display mode displays high resolution display images by expanding and displaying one of the compressed high resolution images. When changing from the fast display mode to the normal display mode, the lower resolution display image currently displayed can be replaced with the corresponding high resolution display image.

Digital Camera Identification from Images --- Estimating False Acceptance Probability

Abstract: Photo-response non-uniformity noise present in output signals of CCD and CMOS sensors has been used as fingerprint to uniquely identify the source digital camera that took the image. The same fingerprint can establish a link between images according to their common source. In this paper, we review the state-of-the-art identification method and discuss its practical issues. In the camera identification task, when formulated as a binary hypothesis test, a decision threshold is set on correlation between image noise and modulated fingerprint. The threshold determines the probability of two kinds of possible errors: false acceptance and missed detection. We will focus on estimation of the false acceptance probability that we wish to keep very low. A straightforward approach involves testing a large number of different camera fingerprints against one image or one camera fingerprint against many images from different sources. Such sampling of the correlation probability distribution is time consuming and expensive while extrapolation of the tails of the distribution is still not reliable. A novel approach is based on cross-correlation analysis and peak-to-correlation-energy ratio.

Designing color filter arrays for the joint capture of visible and near-infrared images

Abstract: Digital camera sensors are inherently sensitive to the near-infrared (NIR) part of the light spectrum. In this paper, we propose a general design for color filter arrays that allow the joint capture of visible/NIR images using a single sensor. We pose the CFA design as a novel spatial domain optimization problem, and provide an efficient iterative procedure that finds (locally) optimal solutions. Numerical experiments confirm the effectiveness of the proposed CFA design, which can simultaneously capture high quality visible and NIR image pairs.

Exact Feature Extraction Using Finite Rate of Innovation Principles With an Application to Image Super-Resolution

Abstract: The accurate registration of multiview images is of central importance in many advanced image processing applications. Image super-resolution, for example, is a typical application where the quality of the super-resolved image is degrading as registration errors increase. Popular registration methods are often based on features extracted from the acquired images. The accuracy of the registration is in this case directly related to the number of extracted features and to the precision at which the features are located: images are best registered when many features are found with a good precision. However, in low-resolution images, only a few features can be extracted and often with a poor precision. By taking a sampling perspective, we propose in this paper new methods for extracting features in low-resolution images in order to develop efficient registration techniques. We consider, in particular, the sampling theory of signals with finite rate of innovation and show that some features of interest for registration can be retrieved perfectly in this framework, thus allowing an exact registration. We also demonstrate through simulations that the sampling model which enables the use of finite rate of innovation principles is well suited for modeling the acquisition of images by a camera. Simulations of image registration and image super-resolution of artificially sampled images are first presented, analyzed and compared to traditional techniques. We finally present favorable experimental results of super-resolution of real images acquired by a digital camera available on the market.

Exemplar-Based Video Inpainting Without Ghost Shadow Artifacts by Maintaining Temporal Continuity

Abstract: Image inpainting or image completion is the technique that automatically restores/completes removed areas in an image. When dealing with a similar problem in video, not only should a robust tracking algorithm be used, but the temporal continuity among video frames also needs to be taken into account, especially when the video has camera motions such as zooming and tilting. In this paper, we extend an exemplar-based image inpainting algorithm by incorporating an improved patch matching strategy for video inpainting. In our proposed algorithm, different motion segments with different temporal continuity call for different candidate patches, which are used to inpaint holes after a selected video object is tracked and removed. The proposed new video inpainting algorithm produces very few ldquoghost shadows,rdquo which were produced by most image inpainting algorithms directly applied on video. Our experiments use different types of videos, including cartoon, video from games, and video from digital camera with different camera motions. Our demonstration at http://member.mine.tku.edu.tw/www/T_CSVT/web/shows the promising results.

Three-Dimensional Assessment of Skin Wounds Using a Standard Digital Camera

Abstract: In this paper, after an overview of the literature concerning the imaging technologies applied to skin wounds assessment, we present an original approach to build 3-D models of skin wounds from color images. The method can deal with uncalibrated images acquired with a handheld digital camera with free zooming. Compared with the cumbersome imaging systems already proposed, this novel solution uses a low-cost and user-friendly image acquisition device suitable for widespread application in health care centers. However, this method entails the development of a robust image processing chain. An original iterative matching scheme is used to generate a dense estimation of the surface geometry from two widely separated views. The best configuration for taking photographs lies between 15deg and 30deg for the vergency angle. The metric reconstruction of the skin wound is fully automated through self-calibration. From the 3-D model of the skin wound, accurate volumetric measurements are achieved. The accuracy of the inferred 3-D surface is validated by registration to a ground truth and repetitive tests on volume. The global precision around 3% is in accordance with the clinical requirement of 5% for assessing the healing process.

Pre- and post-shutter signal image capture and sort for digital camera

Abstract: A camera system includes an image sensor and a processing apparatus receiving image frames from the sensor before and after receipt of a user picture signal. The processing apparatus discards frames that do not meet a quality criterion such as under-exposed frames. Also, the processing apparatus compresses only a subset of remaining frames, specifically, those that meet a compression amount threshold. The remaining frames are presented to a user, who can select a representative frame as the “picture” that was taken.

Crack measurement: Development, testing and applications of an automatic image-based algorithm

Abstract: The paper presents an Image-based Method for Crack Analysis (IMCA) which is capable of processing a sequence of digital imagery to perform a twofold task: (i) the extraction of crack borders and the evaluation of its width across the longitudinal profile; (ii) the measurement of crack deformations (width, sliding and rotation). Here both problems are solved in 2-D, but an extension to 3-D is also addressed. The equipment needed to apply the method is made up of a digital camera (or a still video-camera in case a high frequency in data acquisition is necessary), an orientation frame which establishes the object reference system, a pair of signalized supports to be placed in a permanent way on both sides of the crack to compute deformations; however, permanent targets are mandatory only for case (ii). The measurement process is carried out in a fully automatic way, a fact also that makes this technique highly operational for unskilled people in engineering surveying or photogrammetry. The accuracy of the proposed method, evaluated in experimental tests adopting different consumer digital cameras, is about ± 5–20 μm, like the accuracy of most deformometers, but with the advantage of automation and of augmented achievable information; moreover, the image sequence can be archived and off-line measurements could be performed at any time.

Modular digital camera

Abstract: Modular digital camera systems, such as modular digital still and motion cameras are disclosed. Individual modules may be removed from the system and replaced, such as to benefit from upgraded technology, while preserving the remaining modules in the system. The modules may be disassembled and reconstructed to convert the physical form of the camera, such as between still configurations, motion configurations, ENG configurations, DSLR configurations and studio configurations. Universal lens mount modules are provided, to enable use of lens systems from a variety of commercial manufacturers.

Reduced Energy-Ratio Measure for Robust Autofocusing in Digital Camera

Abstract: A robust and power efficient focus measure applicable in digital cameras is proposed. This measure, namely reduced energy-ratio (RER), uses the dc component and the lowest order five AC components of the discrete cosine transform (DCT) and is expressed as the ratio of the AC and DC components. The low-frequency AC and DC components contain the most energy (information) of an image as well as the detailed edge and base edge information. Autofocus score calculation method is used to assess the performance of the proposed measure and to compare it with other measures. Experimental results under various conditions verify the robustness of the proposed focus measure for the Gaussian as well as impulsive noises.

Imaging device and camera body

Abstract: A digital camera comprises an interchangeable lens unit and a camera body. The interchangeable lens unit is provided to form an optical image of a subject. A flash memory is configured to hold a correction coefficient table used to electrically correct distortion produced by the optical system. The camera body has a CCD image sensor, a correction coefficient acquisition part, an operation part, and a correction processor. The correction coefficient acquisition part is configured to acquire the correction coefficient table held in the flash memory. The operation part is configured to produce correction data by performing an interpolation operation or an extrapolation operation on the information obtained from the correction coefficient table. The correction processor is configured to correct distortion in the image data on the basis of information produced by the operation part.

Composition of a Dewarped and Enhanced Document Image From Two View Images

Abstract: In this paper, we propose an algorithm to compose a geometrically dewarped and visually enhanced image from two document images taken by a digital camera at different angles. Unlike the conventional works that require special equipments or assumptions on the contents of books or complicated image acquisition steps, we estimate the unfolded book or document surface from the corresponding points between two images. For this purpose, the surface and camera matrices are estimated using structure reconstruction, 3-D projection analysis, and random sample consensus-based curve fitting with the cylindrical surface model. Because we do not need any assumption on the contents of books, the proposed method can be applied not only to optical character recognition (OCR), but also to the high-quality digitization of pictures in documents. In addition to the dewarping for a structurally better image, image mosaic is also performed for further improving the visual quality. By finding better parts of images (with less out of focus blur and/or without specular reflections) from either of views, we compose a better image by stitching and blending them. These processes are formulated as energy minimization problems that can be solved using a graph cut method. Experiments on many kinds of book or document images show that the proposed algorithm robustly works and yields visually pleasing results. Also, the OCR rate of the resulting image is comparable to that of document images from a flatbed scanner.

Image pickup apparatus

Abstract: An image pickup apparatus is provided which informs a user of a state of brightness adjusting operation and which has excellent usability for the user. Disclosed is a digital camera including an image adder 5d for synthesizing a plurality of continuously taken image frames to produce a synthesized image, an image processing apparatus 5 for executing image brightness adjusting processing for synthesizing a required synthesis number of image frames and adjusting brightness of the synthesized image at the time of continuous picture-taking of a subject, and a display device for displaying an image which is being synthesized by the image adder in the image brightness adjusting processing.

Digital Camera Imaging System Simulation

Abstract: A digital camera is a complex system including a lens, a sensor (physics and circuits), and a digital image processor, where each component is a sophisticated system on its own. Since prototyping a digital camera is very expensive, it is highly desirable to have the capability to explore the system design tradeoffs and preview the system output ahead of time. An empirical digital imaging system simulation that aims to achieve such a goal is presented. It traces the photons reflected by the objects in a scene through the optics and color filter array, converts photons into electrons with consideration of noise introduced by the system, quantizes the accumulated voltage to digital counts by an analog-to-digital converter, and generates a Bayer raw image just as a real camera does. The simulated images are validated against real system outputs and show a close resemblance to the images captured under similar condition at all illumination levels.

Evaluation of the geometric stability and the accuracy potential of digital cameras - Comparing mechanical stabilisation versus parameterisation

Abstract: Recent tests on the geometric stability of several digital cameras that were not designed for photogrammetric applications have shown that the accomplished accuracies in object space are either limited or that the accuracy potential is not exploited to the fullest extent. A total of 72 calibrations were calculated with four different software products for eleven digital camera models with different hardware setups, some with mechanical fixation of one or more parts. The calibration procedure was chosen in accord to a German guideline for evaluation of optical 3D measuring systems [VDI/VDE, VDI/VDE 2634 Part 1, 2002. Optical 3D Measuring Systems–Imaging Systems with Point-by-point Probing. Beuth Verlag, Berlin]. All images were taken with ringflashes which was considered a standard method for close-range photogrammetry. In cases where the flash was mounted to the lens, the force exerted on the lens tube and the camera mount greatly reduced the accomplished accuracy. Mounting the ringflash to the camera instead resulted in a large improvement of accuracy in object space. For standard calibration best accuracies in object space were accomplished with a Canon EOS 5D and a 35 mm Canon lens where the focusing tube was fixed with epoxy (47 μm maximum absolute length measurement error in object space). The fixation of the Canon lens was fairly easy and inexpensive resulting in a sevenfold increase in accuracy compared with the same lens type without modification. A similar accuracy was accomplished with a Nikon D3 when mounting the ringflash to the camera instead of the lens (52 μm maximum absolute length measurement error in object space). Parameterisation of geometric instabilities by introduction of an image variant interior orientation in the calibration process improved results for most cameras. In this case, a modified Alpa 12 WA yielded the best results (29 μm maximum absolute length measurement error in object space). Extending the parameter model with FiBun software to model not only an image variant interior orientation, but also deformations in the sensor domain of the cameras, showed significant improvements only for a small group of cameras. The Nikon D3 camera yielded the best overall accuracy (25 μm maximum absolute length measurement error in object space) with this calibration procedure indicating at the same time the presence of image invariant error in the sensor domain. Overall, calibration results showed that digital cameras can be applied for an accurate photogrammetric survey and that only a little effort was sufficient to greatly improve the accuracy potential of digital cameras.

A camera as a sensor for lighting and shading control

Abstract: We developed a proof-of-concept prototype camera-based system for lighting and shading control. The system utilised a simple CMOS-based digital camera with an approximate v-lambda filter, calibrate...

Particle surface temperature measurements with multicolor band pyrometry

Abstract: A noncontact, color-band pyrometer, based on widely available, inexpensive digital imaging devices, such as commercial color cameras, and capable of pixel-by-pixel resolution of particle-surface temperature and emissivity is demonstrated and described. This diagnostic instrument is ideally suited to many combustion environments. The devices used in this method include color charge-coupled device (CCD), or complementary metal oxide semiconductor (CMOS) digital camera, or any other color-rendering camera. The color camera provides spectrally resolved light intensity data of the image, most commonly for three color bands (Red, Green, and Blue,), but in some cases for four or more bands or for a different set of colors. The CCD or CMOS sensor-mask combination has a specific spectral response curve for each of these color bands that spans the visible and often near infrared spectral range. A theory is developed, based on radiative heat transfer and camera responsivity that allows quantitative surface temperature distribution calculation, based on a photograph of an object in emitted light. Particle surface temperature calculation is corrected by heat transfer analysis with reflection between the particle and reactor wall for particles located in furnace environments, but such corrections lead to useful results only when the particle temperature is near or below the wall temperatures. Wood particle-surface temperatures were measured with this color-band pyrometry during pyrolysis and combustion processes, which agree well with thermocouple measured data. Particle-surface temperature data simultaneously measured from three orthogonal directions were also mapped onto the surface of a computer generated 3-D (three-dimensional) particle model. © 2008 American Institute of Chemical Engineers AIChE J, 2009

Distance measurement based on pixel variation of CCD images.

Abstract: This paper presents a distance measurement method based on pixel number variation of CCD images by referencing to two arbitrarily designated points in the image frames. By establishing a relationship between the displacement of the camera movement along the photographing direction and the difference in pixel count between reference points in the images, the distance from an object can be calculated via the proposed method. To integrate the measuring functions into digital cameras, a circuit design implementing the proposed measuring system in selecting reference points, measuring distance, and displaying measurement results on CCD panel of the digital camera is proposed in this paper. In comparison to pattern recognition or image analysis methods, the proposed measuring approach is simple and straightforward for practical implementation into digital cameras. To validate the performance of the proposed method, measurement results using the proposed method and ultrasonic rangefinders are also presented in this paper.

Partial face detector red-eye filter method and apparatus

Abstract: A digital camera has an integral flash and stores and displays a digital image. Under certain conditions, a flash photograph taken with the camera may result in a red-eye phenomenon due to a reflection within an eye of a subject of the photograph. A digital apparatus has a red-eye filter which analyzes at least one partial face region identified within the digital image for the red-eye phenomenon and modifies the image to eliminate the red-eye phenomenon by changing the red area to black. The modification of the image is enabled when a photograph is taken under conditions indicative of the red-eye phenomenon. The modification is subject to anti-falsing analysis which further examines the area around the red-eye area for indicia of the eye of the subject. The detection and correction can be optimized for performance and quality by operating on subsample versions of the image when appropriate.

Evaluation of three-dimensional surface roughness parameters based on digital image processing.

Abstract: With the development and application of optoelectric technology, laser technology and computer technology in mind, we have developed a method to evaluate three-dimensional surface roughness using surface profile information. This article proposes a three-dimensional measuring technique, which is used to survey components surface roughness, based on the digital image processing technology, and establishes athree-dimensional surface roughness evaluation system consisting of both hardware and software architecture. The hardware used in the present experiment is listed as follows: a stereomicroscope, a digital camera with special interface, a parallel light (by halogen lamp), an X, Y bidirectional laboratory bench and a computer. A computer-aided system (CAS), developed with Visual C++ , is used in the image pretreatment and data processing analysis. In the experiment, image information gathered from the digital camera is pre-processed by median filtering, grayscale equalization and histogram conversion amplification. Then the data are analyzed by normalized cross-correlation and surface fitting techniques. Lastly, the correlation between m, σ, Sq, S ku and Ra is discussed for different surface roughness specimens.

Method for digital photo management and distribution

Abstract: Digital images are captured on a digital camera, automatically formatted, and uploaded to a server for review and collaborative modifications. An on-line web gallery is automatically generated by the server whereby low resolution versions of the images are transferred to the server and appear in the gallery within seconds from capturing the images. Among other things, a viewer located remotely from a photographer can observe new images in the gallery in real time as they are captured, place a request for post-production modifications to selected images and download a high resolution version of selected images.