Showing papers on "Image sensor published in 2002"

Endoscopic ablation system with a distally mounted image sensor

Abstract: A tissue ablation system is described. The tissue ablation system can include a plurality of electrodes, a viewing window between adjacent electrodes, illuminating elements, and an image sensor. The image sensor can be a CMOS device.

New paradigm for imaging systems

Abstract: We describe a new paradigm for designing hybrid imaging systems. These imaging systems use optics with a special aspheric surface to code the image so that the point-spread function or the modulation transfer function has specified characteristics. Signal processing then decodes the detected image. The coding can be done so that the depth of focus can be extended. This allows the manufacturing tolerance to be reduced, focus-related aberrations to be controlled, and imaging systems to be constructed with only one optical element plus some signal processing. OCIS codes: 080.3620, 110.0110, 110.2990, 110.0180, 110.4850, 180.0180. 1. Introduction and Background The new paradigm that we describe for the design of imaging systems has been termed wave-front coding. These coded optical systems are arrived at by means of designing the coding optics and the signal processing as an integrated imaging system. The results are imaging systems with previously unobtainable imaging modalities and require a modification of the optics for coding the wave in the aperture stop or an image of the aperture stop. This coding produces an intermediate image formed by the optical portion of the system that gathers the image. Signal processing is then required for decoding the intermediate image to produce a final image. The coding can be designed to make the imaging system invariant to certain parameters or to optimize the imaging system’s sensitivity to those parameters. One example is the use of image coding to preserve misfocus and hence, range or distance information. Another example is the use of different types of codes to make the image invariant to misfocus. These new focusinvariant imaging systems can have more than an order of magnitude increase in the depth of field. Our emphasis in this paper is on the use of the increased depth of focus to design new types of imaging systems. An example of the new imaging systems that can be constructed is a single-element lens that has a small F#, wide field of view, and diffractionlimited imaging. It also can have greatly relaxed assembly tolerances, because of its invariance to focus-related aberrations. Coding of signals for optimally conveying particular information is not new. In radar the transmitted pulses are coded for optimally providing information concerning a target’s range, for example. The appropriate signal processing to extract the range information is designed in conjunction with the transmitted signal. The integrated design of the optical image-gathering portion along with the signal processing normally is not done in the design of imaging systems. There are exceptions such as tomography, coded aperture imaging, and sometimes, interferometric imaging. In 1984 a group that was investigating the limits of resolution pointed out the potential of increasing the performance of imaging systems by jointly designing the optics and the signal processing. 1

Integral three-dimensional imaging with digital reconstruction

Abstract: A computer-based three-dimensional image reconstruction method and system are presented. An elemental image array of a three-dimensional object is formed by a micro-lens array, and recorded by a CCD camera. Three-dimensional images are reconstructed by extracting pixels periodically from the elemental image array using a computer. Images viewed from an arbitrary angle can be retrieved by shifting which pixels are to be extracted. Image processing methods can be used to enhance the reconstructed image. Further, the digitally reconstructed images can be sent via a network. A system for imaging a three-dimensional object includes a micro-lens array that generates an elemental image array. The elemental image array is detected by a CCD camera to generate digitized image information. A computer processes the digitized image information to reconstruct an image of the three-dimensional object. A two-dimensional display device may be connected directly or indirectly to the computer to display the image of the three-dimensional object. The computer may also be used to generate virtual image information of a virtual three-dimensional object. This can then be combined with the digitized image information to provide combined image information. The two-dimensional display device may be used to display a virtual image or a combined image.

Cone-beam volume CT breast imaging: feasibility study.

Abstract: X-ray projection mammography, using a film/screen combination, or digital techniques, has proven to be the most effective imaging modality currently available for early detection of breast cancer. However, the inherent superimposition of structures makes a small carcinoma (a few millimeters in size) difficult to detect when it is occult or in dense breasts, leading to a high false-positive biopsy rate. Cone-beam x-ray-projection-based volume imaging using flat panel detectors (FPDs) may allow obtaining three-dimensional breast images, resulting in more accurate diagnosis of structures and patterns of lesions while eliminating the hard compression of breasts. This article presents a novel cone-beam volume computed tomographic breast imaging (CBVCTBI) technique based on the above techniques. Through a variety of computer simulations, the key issues of the system and imaging techniques were addressed, including the x-ray imaging geometry and corresponding reconstruction algorithms, x-ray characteristics of breast tissue and lesions, x-ray setting techniques, the absorbed dose estimation, and the quantitative effect of x-ray scattering on image quality. The preliminary simulation results support the proposed CVBCTBI modality for breast imaging in respect to its feasibility and practicability. The absorbed dose level is comparable to that of current mammography and will not be a prominent problem for this imaging technique. Compared to conventional mammography, the proposed imaging technique with isotropic spatial resolution will potentially provide significantly better low-contrast detectability of breast tumors and more accurate location of breast lesions.

Optical reader having partial frame operating mode

Abstract: The invention is an optical reader having a 2D image sensor that is configured to operate in a partial frame capture mode. In a partial frame operating mode, the reader clocks out and captures at least one partial frame of image data having image data corresponding to less than all of the pixels of an image sensor pixel array. In one embodiment, the reader operating in a partial frame operating mode captures image data corresponding to a linear pattern of pixels of the image sensor, reads the image data, attempts to decode for a decodable 1D symbol which may be represented in the image data, and captures a full frame of image data if the image data reading reveals a 2D symbol is likely to be present in a full field of view of the 2D image sensor.

Real-time three-dimensional object reconstruction by use of a phase-encoded digital hologram.

Abstract: A three-dimensional (3D) object reconstruction technique that uses only phase information of a phase-shifting digital hologram and a phase-only spatial-light modulator is proposed. It is well known that a digital hologram can store both amplitude and phase information of an optical electric field and can reconstruct the original 3D object in a computer. We demonstrate that it is possible to reconstruct optically 3D objects using only phase information of the optical field calculated from phase-shifting digital holograms. The use of phase-only information enables us to reduce the amount of data in the digital hologram and reconstruct optically the 3D objects using a liquid-crystal spatial light modulator without optical power loss. Numerical evaluation of the reconstructed 3D object is presented.

Direct-conversion flat-panel X-ray image sensors for digital radiography

Abstract: Advances in active-matrix array flat panels for displays over the last decade have led to the development of flat-panel X-ray image detectors. Recent flat-panel detectors have shown image quality exceeding that of X-ray film/screen cassettes. They can also permit the instantaneous capture, readout, and display of digital X-ray images and, hence, enable the clinical transition to digital radiography. There are two general approaches to flat panel detector technology: 1) direct and 2) indirect conversion. The present paper outlines the operating principles for direct-conversion detectors based on the use of photoconductors. It formulates and reviews the required X-ray photoconductor properties for such applications and examines to what extent potential materials fulfill these requirements. The quantum efficiency, X-ray sensitivity, noise, and detective quantum efficiency factors are discussed with reference to current and potential large area X-ray photoconductors.

Digital off-axis holography with a synthetic aperture.

Abstract: The use of a synthetic aperture is demonstrated as part of an off-axis setup for digital holography. The aperture was constructed from camera recordings at nine different positions. An algorithm to reconstruct object sections, which requires only moderate computer memory, was used. The result shows strongly improved resolution.

Multiscale displacement field measurements of compressed mineral-wool samples by digital image correlation

Abstract: We propose a multiscale approach to determine the displacement field by digital image correlation. The displacement field is first estimated on a coarse resolution image and progressively finer details are introduced in the analysis as the displacement is more and more securely and accurately determined. Such a scheme has been developed to increase the robustness, accuracy, and reliability of the image-matching algorithm. The procedure is used on two different types of examples. The first one deals with a representative image that is deformed precisely and purposefully to assess the intrinsic performances. In particular, the maximum measurable strain is determined. The second case deals with a series of pictures taken during compression experiments on mineral-wool samples. The different steps of the procedure are analyzed and their respective role is assessed. Both reflection and transmission images are tested.

Comparison of PbI2 and HgI2 for direct detection active matrix x-ray image sensors

Abstract: The factors determining the x-ray sensitivity of HgI2 and PbI2 as direct detector materials for large area matrix addressed x-ray image sensors are described, along with a model to explain their different properties. The imaging studies are made on test arrays with 512×512 pixels of size 100 μm. The x-ray sensitivity and spatial resolution are reported, along with measurements of the various mechanisms that influence the sensitivity, such as charge collection, x-ray absorption, fill factor, and image lag. The spatial resolution of PbI2 decreases with increasing film thickness, but this effect is not observed in HgI2. The x-ray response data are used to compare the sensitivity to the theoretical values for the ionization energy and to identify the various loss mechanisms. We find that the sensitivity of HgI2 can be explained by a few small and well characterized loss factors. This material exhibits good spatial resolution, high fill factor, and high charge collection. PbI2 films exhibit lower sensitivity, principally attributable to a very large image lag. We propose that the x-ray response of the two materials is distinguished by their different depletion layer properties, and present a model that accounts for the sensitivity, image lag, and spatial resolution of PbI2.

Short-coherence digital microscopy by use of a lensless holographic imaging system

Abstract: An optical system based on short-coherence digital holography suitable for three-dimensional (3D) microscopic investigations is described. The light source is a short-coherence laser, and the holograms are recorded on a CCD sensor. The interference (hologram) occurs only when the path lengths of the reference and the object beam are matched within the coherence length of the laser. The image of the part of the sample that matches the reference beam is reconstructed by numerical evaluation of the hologram. The advantages of the method are high numerical aperture (this means high spatial resolution), detection of the 3D shape, and a lensless imaging system. Experimental results are presented.

Method and apparatus for inspecting pattern defects

Abstract: A method and apparatus for inspecting pattern defects emitting a laser beam, adjusting a light-amount of the laser beam, converting the light-amount adjusted laser beam into a slit-like laser light flux, lowering coherency of the slit-like laser light flux, and irradiating a sample with the coherence reduced slit-like laser light flux. An image of reflection light from the sample is obtained, and a detector is provided which includes the image sensor for receiving the image of the reflection light and for converting it into a detected image signal. An image processor is provided for detecting defects on patterns formed on the sample in accordance with the detected image signal.

Encyclopedia of imaging science and technology

Abstract: Final Title List. Article Title, Category, Total mss -- 82. Acoustic Sources or Receiver Arrays: Directional Response Characteristics of, Detector Technology. Analog and Digital SQUID Sensors, Detector Technology. Capacitive Probe Microscopy, Imaging Techniques Systems. Cathode Ray Tube Display Technology, Display Technology. Cathode Ray Tubes, Display Technology. Characterization of Image Systems, End User. Charged Particle Optics, Image Formation. Color Image Processing, Digital Image Processing. Color Photography, Imaging Techniques Systems. Digital Video, Display Technology. Digital Watermarking, Digital Image Processing. Display Calibration, End User. Dye Transfer Printing Technology, Display Technology. Electroencephalogram (EEG) Topography, Imaging Techniques Systems. Electromagnetic Radiation and Interactions with Matter, Spectroscopy. Electron Microscopes, Imaging Techniques Systems. Electron Paramagnetic Resonance (EPR) Imaging, Imaging Techniques Systems. Electrophotography, Imaging Techniques Systems. Endoscopy, Imaging Techniques Systems. Feature Measurement, Digital Image Processing. Feature Recognition Object Classification , Digital Image Processing. Field Emission Display Panels, Display Technology. Flow Imaging, Imaging Techniques Systems. Force Imaging, Imaging Techniques Systems. Foundations of Morphological Image Processing, Digital Image Processing. Gravitation Imaging, Imaging Techniques Systems. Gravure Multi--Copy Printing, Display Technology. Ground Penetrating Radar, Imaging Techniques Systems. High Resolution Secondary Ion Mass Spectroscopy Imaging, Imaging Techniques Systems. High Speed Photographic Imaging, Imaging Techniques Systems. Holography, Imaging Techniques Systems. Human Visual System -- Color Visual Processing, End User. Human Visual System -- Image Formation, End User. Human Visual System -- Spatial Visual Processing, End User. Image Formation, Image Formation. Image Processing Techniques, Digital Image Processing. Image Quality Metrics, End User. Image Search and Retrieval Strategies, Digital Image Processing. Image Threshold and Segmentation, Digital Image Processing. Imaging Applied to the Geologic Sciences, Imaging Applications. Imaging Science in Art Conservation, Imaging Applications. Imaging Science in Astronomy, Imaging Applications. Imaging Science in Biochemistry, Imaging Applications. Imaging Science in Forensics & Criminology, Imaging Applications. Imaging Science in Medicine, Imaging Applications. Imaging Science in Meteorology, Imaging Applications. Imaging Science in Overhead Surveillance, Imaging Applications. Infrared Thermography , Imaging Techniques & Systems. Ink Jet Printing for Organic Electroluminescent Display, Display Technology. Instant Photography, Imaging Techniques & Systems. Laser--Induced Fluorescence Imaging, Imaging Techniques & Systems. LIDAR, Imaging Techniques & Systems. Lightning Locator, Imaging Techniques & Systems. Liquid Crystal Display Technology, Display Technology. Magnetic Field Imaging, Imaging Techniques & Systems. Magnetic Resonance Imaging, Imaging Techniques & Systems. Magnetospheric Imaging, Imaging Techniques & Systems. Motion Picture Photography, Imaging Techniques & Systems. Neutron Imaging, Radiography, and CT, Imaging Techniques & Systems. Optical Image Formation, Image Formation. Optical Microscopy, Imaging Techniques & Systems. Over the horizon (OTH) Radar, Imaging Techniques & Systems. Particle Detector Technology for Imaging, Detector Technology. Photoconductor Detector Technology, Detector Technology. Photodetectors, Detector Technology. Photographic Color Display Technology, Display Technology. RF Magnetic Field Mapping, Imaging Techniques & Systems. Scanning Acoustic Microscopy, Imaging Techniques & Systems. Scanning Electrochemical Microscopy, Imaging Techniques & Systems. Silver Halide Detector Technology, Detector Technology. Single Photon Emission Computed Tomography (SPECT), Imaging Techniques & Systems. Stereo & 3D Display Technologies, Display Technology. Still Photography, Imaging Techniques & Systems. Television Broadcast Transmission Standards, Imaging Techniques & Systems. Terahertz Electric Field Imaging, Imaging Techniques & Systems. Tomographic Image Formation Techniques, Image Formation. Ultrasound Imaging, Imaging Techniques & Systems. Video Recording, Display Technology. Wavelet Transforms, Digital Image Processing. Weather Radar, Imaging Techniques & Systems. X--Ray Fluorescence Imaging , Imaging Techniques & Systems. X--Ray Telescope, Imaging Techniques & Systems.

Measuring system with improved method of reading image data of an object

Abstract: When a scanning start position set signal is input in an area image sensor, the content is transferred to a vertical scanning circuit, and the scan start position is set. Image of a desired row is read by horizontal scanning. Then, one shift signal for vertical scanning is input, the position of scanning is shifted by one row, and horizontal scanning is performed. Thus image of the next row is read. By repeating this operation, a desired strip-shaped image is read. The shape of the object is determined and when a portion is determined to have complicated shape, the image data is input by means of a lens having long focal length, and image data of other portions are input by means of a lens having short focal length. By putting together a plurality of input image data, image data as a whole is generated.

Exposure control method for use with optical readers

Abstract: An exposure control apparatus for use with optical readers, such as bar code readers, which utilize photosensitive image sensors. An illumination signal generating circuit generates an illumination signal having a magnitude that varies in accordance with the illumination level at the image sensor. A window detecting circuit samples the illumination signal during a predetermined part of each scan to determine whether the illumination signal is within the window, has exited the widow, or has re-entered the window. Exposure control circuitry uses the output of the window detecting circuit to control which of a plurality of the subdivisions of the exposure control range of the image sensor will be used. Changes in exposure time are made only between adjacent subdivisions of the exposure control range. Together with a predetermined hysteresis between the exit and re-entry thresholds of the window, the latter changes stabilize the operation of the reader by reducing exposure control “hunting”.

System and method to increase effective dynamic range of image sensors

Abstract: A system and method of increasing the dynamic range of image sensors by controlling the exposure (either electronically or mechanically) of multiple images and optionally forming a composite image from the properly exposed areas of the multiple images of varying exposure settings. Certain embodiments of the system and method utilize image processing techniques to determine the various exposure settings and to form the optional composite image. The properly exposed areas can be used directly by machine vision applications.

Trends in CMOS image sensor technology and design

Abstract: Three trends that promise to increase CMOS image sensor system performance are presented: (i) modifications of deep submicron CMOS processes to improve their imaging characteristics, (ii) developments that take advantage of these modified deep submicron processes, and (iii) high frame rate sensors and applications to still and video imaging, specifically to extending sensor dynamic range. Recent research on Digital Pixel Sensors and applications of its high frame rate to still and video imaging are discussed.

Position detector and attitude detector

Abstract: A position detector displays a target on a given plane and adds a standard on the given plane in the vicinity of the target with the location of the standard known. An image of the given plane is formed on an image plane of an image sensor with an image of the standard included, a point in the image of the given plane which is formed at a predetermined position of the image plane corresponding to the point to be detected. An image processor identifies the image of the standard on the image plane to calculate the position of the point to be detected. The standard includes asymmetric pattern. The standard includes a first standard and a second standard sequentially added on the given plane, the difference being calculated accompanied with the plus sign or the minus sign. The image on the given plane is formed by means of a scanning, the image sensor reads out the sensed image upon the termination of at least one period of the scanning. The second standard is added upon the initiation of the scanning after the completion of reading out of the image of the first standard.

Producing a defective pixel map from defective cluster pixels in an area array image sensor

Abstract: A method for determining one or more defective pixels in an area array image sensor wherein such defects can form a defective cluster and for producing a defect map which can be used in a digital camera for image correction includes capturing a digital image using the image sensor and storing such digital image in a memory; identifying a plurality of defective pixels which form a defective cluster in the digital image by processing the digital image data using a localized averaging filter; and forming a map identifying the location of the defective cluster in the digital image.

Induction powered in vivo imaging device

Abstract: An in vivo imaging device including at least one image sensor (14) and an energy receiving unit (19) that is configured to receive electromagnetic energy (46) and to convert the received electromagnetic energy to energy for powering at least one electrical component of the image sensor.

Moisture sensor utilizing stereo imaging with an image sensor

Abstract: A moisture sensing system of the present invention includes first and second sensor arrays (32), at least one optical system operative (33) to image the same portion of the surface onto both of the sensor arrays, and a processing system in communication with the sensor arrays and operative to analyze images from the sensor arrays that are separate or different portions of the same array. This system may be used to control the windshield wipers of a vehicle. The processing system may be configured to subtract an image obtained from the first array from an image obtained from the second sensor array to distinguish between near field and far field objects.

Eyeing the Camera: Into the Next Century*

Abstract: In the two centuries of photography, there has been a wealth of invention and innovation aimed at capturing a realistic and pleasing full-color twodimensional representation of a scene. In this paper, we look back at the historical milestones of color photography and bring into focus a fascinating parallelism between the evolution of chemical based color imaging starting over a century ago, and the evolution of electronic photography which continues today. The second part of our paper is dedicated to a technical discussion of the new Foveon X3 multilayer color image sensor; what could be descried as a new more advanced species of camera sensor technology. The X3 technology is compared to other competing sensor technologies; we compare spectral sensitivities using one of many possible figures of merit. Finally we show and describe how, like the human visual system, the Foveon X3 sensor has an inherent luminancechrominance behavior which results in higher image quality using fewer image pixels.

Digital watermarking methods, programs and apparatus

Abstract: The present claims recite various steganographic and digital watermarking methods and apparatus. One claim recites a method of watermarking a representation of a physical object. The method includes: projecting a watermark orientation component onto a physical object; and using a camera or image sensor, capturing an image or video of the physical object including the watermark orientation component as projected thereon. Another claim recites an apparatus including: a light source for projecting a registration component onto a physical object; a camera or sensor for capturing an image or video of the physical object including the registration component as projected thereon; and an electronic processor programmed for encoding a message in the image or video captured by said camera or sensor. Of course, other claims and combinations are provided as well.

Novel CMOS image sensor with a 132-dB dynamic range

Abstract: A CMOS image sensor providing an ultrawide dynamic range with a piecewise linear response is presented. The active pixel is based on a novel architecture which implements a voltage comparator and an analog memory to detect and store the information on the integration time needed to reach saturation, while also maintaining the standard integrated photo-current signal. A 128/spl times/64 pixel array has been designed and fabricated in 0.35-/spl mu/m, 3.3-V CMOS technology. The chip measures 2.67/spl times/4.90 mm/sup 2/ with a pixel size of 24.65/spl times/24.65 /spl mu/m/sup 2/ and a fill factor of about 11%. The sensor has been fully characterized and the measured dynamic range turned out to be 132 dB with a power consumption of 14 mW at video frame rate. The sensor features also good noise performance with a temporal noise of 0.2% (1.7%) and a fixed pattern noise of 0.4% (1.5%) at low (high) irradiance.

Motion measuring device

Abstract: Endoscopes are well known devices used for examining surfaces contained within an enclosed cavity. Typical applications for these devices are the examination of tissues within human body cavities or mechanical components contained within engine compartments. An endoscopic apparatus for measuring blood flow contained within an enclosed body cavity is claimed. Such apparatus comprises an electromagnetic radiation source for emitting a coherent beam, an optical relay system for propagating the beam down an endoscopic probe to illuminate a target within an enclosed cavity, an endoscopic optical relay system for capturing the reflected light and transmitting an image of the illuminated region onto the surface of a two-dimensional image sensor, an analog to digital conversion device for capturing analog output signals from the image sensor for conversion to digital format, a display device for immediate visual display of captured images, a method for calculating flow values from a captured digital image containing speckle structure information of the laser illuminated surface, a memory device for storing digital blood flow images, and a display device for immediate visual display of color coded, blood flow images.

Solid-state image sensor, production method of the same, and digital camera

Abstract: The present invention provides a solid-state image sensor wherein the color shading is decreased, and/or a solid-state image sensor wherein the shading effect is outstanding Moreover, the invention provides a digital camera having the solid-state image sensor The solid-state image sensor of the present invention has color filters and/or apertures of a light blocking layer, and the center of the color filters and/or the center of the apertures of the light blocking layer is offset with respect to the center of a light-receiving part, in the direction to the center of a valid cell area In each photodetecting cell of a preferred solid-state image sensor, micro-lenses are further placed on the light-receiving side of the solid-state image sensor, and preferably, the center of the micro-lens is similarly offset with respect to the center of the light-receiving part Also, the digital camera is mounted with an above-described solid-state image sensor

Image sensing apparatus including a microcontroller

Abstract: An image sensing and processing apparatus includes an image sensor that is capable of generating signals carrying data relating to an image sensed by the image sensor. The apparatus includes a microcontroller. The microcontroller includes a wafer substrate. VLIW processor circuitry is positioned on the wafer substrate. Image sensor interface circuitry is positioned on the wafer substrate and is connected between the VLIW processor circuitry and the image sensor. The image sensor interface circuitry is configured to facilitate communication between the VLIW processor circuitry and the image sensor. Bus interface circuitry that is discrete from the image sensor interface circuitry is connected to the VLIW processor circuitry so that the VLIW processor circuitry can communicate with devices other than the image sensor via a bus.

Rectified catadioptric stereo sensors

Abstract: It has been shown elsewhere how mirrors can be used to capture stereo images with a single camera, an approach termed catadioptric stereo. We present novel catadioptric sensors that use mirrors to produce rectified stereo images. The scanline correspondence of these images benefits real-time stereo by avoiding the computational cost and image degradation due to resampling when rectification is performed after image capture. First, we develop a theory which determines the number of mirrors that must be used and the constraints on those mirrors that must be satisfied to obtain rectified stereo images with a single camera. Then, we discuss in detail the use of both one and three mirrors. In addition, we show how the mirrors should be placed in order to minimize sensor size for a given baseline, an important design consideration. In order to understand the feasibility of building these sensors, we analyze rectification errors due to misplacement of the camera with respect to the mirrors.

Electronic endoscope system with color-balance alteration process

Abstract: An electronic endoscope system includes a video scope having a solid-state image sensor for successively producing a frame of color image-pixel signals, and an image-signal processor for producing a color video signal based on the frame of color image-pixel signals. A calculation system calculates a difference value between a value of a central single-color image-pixel signal and an average of values of one selected from single-color image-pixel signals surrounding the central single-color image-pixel signal. A color-balance alteration system alters the value of the central single-color image-pixel signal based on the difference value calculated by the calculation system. A selection system performs the selection of the circumferential image-pixel signals such that the circumferential image-pixel signals to be selected are farther from the central image-pixel signal, as a spatial frequency of an endoscope image to be reproduced based on the color video signals is lower.

MR Platform: a basic body on which mixed reality applications are built

Abstract: This paper describes a platform package, called "MR Platform," which we have been implementing for research and development of augmented reality technology and applications. This package includes a parallax-less stereo video see-through HMD and a software development kit (SDK) for a Linux PC environment. The SDK is composed of a C++ class library for making runtime MR applications and related utilities such as a camera calibration tool. By using the SDK, the following functions are available: capturing video, handling a six degree-of-freedom (DOF) sensor, image processing such as color detection, estimating head position and orientation, displaying the real world image, and calibrating sensor placement and camera parameters of two cameras mounted on the HMD.