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We propose a concept for a lens attachment that turns a standard DSLR camera and lens into a light field camera. The attachment consists of eight low-resolution, low-quality side cameras arranged around the central high-quality SLR lens. Unlike most existing light field camera architectures, this design provides a high-quality 2D image mode, while simultaneously enabling a new high-quality light field mode with a large camera baseline but little added weight, cost, or bulk compared with the base DSLR camera. From an algorithmic point of view, the high-quality light field mode is made possible by a new light field super-resolution method that first improves the spatial resolution and image quality of the side cameras and then interpolates additional views as needed. At the heart of this process is a super-resolution method that we call iterative Patch- And Depth-based Synthesis (iPADS), which combines patch-based and depth-based synthesis in a novel fashion. Experimental results obtained for both real captured data and synthetic data confirm that our method achieves substantial improvements in super-resolution for side-view images as well as the high-quality and view-coherent rendering of dense and high-resolution light fields.

The best digital cameras today are SLRs (single-lens reflex cameras), which use a movable mirror to guide the same light rays that fall on the sensor into the viewfinder. These cameras normally have precisely ground glass lenses and large, high-quality image sensors. In the right hands, they can shoot amazing pictures, with brilliant colors and pleasing lighting effects, often showing a crisply focused subject and an aesthetically blurred background. But these cameras are big, heavy, and expensive: A good digital SLR (DSLR) with a decent set of lenses–including a standard 50 mm, a wide angle, and a telephoto, for example–can easily set you back thousands of dollars.

Light field cameras are becoming popular in computer vision and graphics, with many research and commercial applications already having been proposed. Various types of cameras have been developed with the camera array being one of the ways of acquiring a 4D light field image using multiple cameras. Camera calibration is essential, since each application requires the correct projection and ray geometry of the light field. The calibrated parameters are used in the light field image rectified from the images captured by multiple cameras. Various camera calibration approaches have been proposed for a single camera, multiple cameras, and a moving camera. However, although these approaches can be applied to calibrating camera arrays, they are not effective in terms of accuracy and computational cost. Moreover, less attention has been paid to camera calibration of a light field camera. In this paper, we propose a calibration method for a camera array and a rectification method for generating a light field image from the captured images. We propose a two-step algorithm consisting of closed form initialization and nonlinear refinement, which extends Zhang's well-known method to the camera array. More importantly, we introduce a rigid camera constraint whereby the array of cameras is rigidly aligned in the camera array and utilize this constraint in our calibration. Using this constraint, we obtained much faster and more accurate calibration results in the experiments.

One of the strongest limiting factors in close range photogrammetry (CRP) is the depth of field (DOF), especially at very small object distance. When using standard digital cameras and lens, for a specific camera – lens combination, the only way to control the extent of the zone of sharp focus in object space is to reduce the aperture of the lens. However, this strategy is often not sufficient; moreover, in many cases it is not fully advisable. In fact, when the aperture is closed down, images lose sharpness because of diffraction. Furthermore, the exposure time must be lowered (susceptibility to vibrations) and the ISO increased (electronic noise may increase). In order to adapt the shape of the DOF to the subject of interest, the Scheimpflug rule is to be applied, requiring that the optical axis must be no longer perpendicular to the image plane. Nowadays, specific lenses exist that allow inclining the optical axis to modify the DOF: they are called tilt-shift lenses. In this paper, an investigation on the applicability of the classic photogrammetric model (pinhole camera coupled with Brown’s distortion model) to these lenses is presented. Tests were carried out in an environmentally controlled metrology laboratory at the National Research Council (NRC) Canada and the results are hereafter described in detail., XXIII ISPRS Congress, July, 12–19, 2016, Prague, Czech Republic

An aperture sharing camera to acquire multiview images are introduced. The camera is built with a mirrorless camera and a high speed LC shutter array which is located at the entrance pupil of the camera’s objective, to divide the pupil into a number of sections with an equal dimension, The LC shutters in the array is opened one at a time in synchronizing with the camera shutter. The images from neighboring shutters reveal a constant disparity between them. The disparity between the images from the camera matches closely with that calculated from theory and is proportional to the distance of the each LC shutter from the camera’s optical axis.

Objectives: Recent high zoom lens as CCD (Charge Coupled Device) camera is released with the resolution to be able to easily acquire the digital image that has been variously utilized, from day-to-day utilization to take advantage of specialized domain such as computer vision (computer vision). It has a number of advantages for obtaining a normal zoom lens CCD camera video which is now commercially available, however the camera calibration in the actual image process geometrically have been the considerable difficulties due to the unstable capture and the movement of the pick-up process in a variety of zoom lens camera. Methods: The camera parameters for the zoom lens calibration will be test variables calculated over a camera lens, a variety of focal lengths whenever the zoom occur, especially if you already have zoom movement at the point the lens test is complete, recalculation of the camera calibration parameters cause the difficulties. In this research the zoom lens to correct the distortion of image obtaining the camera calibration, and a method that extracts the camera parameters through the DLT (Direct Linear Transformation) test method is proposed. Findings: DLT accuracy of the camera is black was carried out in the following two aspects. The first was to analyze the three dimensional position differences between the estimated position and the actual three-dimensional observation that is calculated by the model formula to moderate, and the second is that pixel position that is pixels accuracy projected onto the image plane in the three-dimensional space of the object the accuracy was evaluated in an absolute manner. In this study, under the assumption that the aperture condition is fixed zoom, the zoom was determined the relationship between the camera and variable focus for the condition setting. A zoom lens camera model by setting the zoom and focus conditions at regular intervals as short-focus lens model was established by the DLT method and each camera parameter is tested individually. Applications: In future research the image correction software will be develop for the 3-dimensional location information based on three-dimensional information generating process based on camera calibration method by the DLT method.

We consider the problem of camera pose estimation for a scenario where the camera may have continuous and unknown changes in its focal length. Understanding frame by frame changes in camera focal length is vital to accurately estimating camera pose and vital to accurately rendering virtual objects in a scene with the correct perspective. However, most approaches to camera calibration require geometric constraints from many frames or the observation of a 3D calibration object — both of which may not be feasible in augmented reality settings. This paper introduces a calibration object based on a flat lenticular array that creates a color coded light-field whose observed color changes depending on the angle from which it is viewed. We derive an approach to estimate the focal length of the camera and the relative pose of an object from a single image. We characterize the performance of camera calibration across various focal lengths and camera models, and we demonstrate the advantages of the focal length estimation in rendering a virtual object in a video with constant zooming.

Designing a cryogenic camera is a good strategy to miniaturize and simplify an infrared camera using a cooled detector. Indeed, the integration of optics inside the cold shield allows to simply athermalize the design, guarantees a cold pupil and releases the constraint on having a high back focal length for small focal length systems. By this way, cameras made of a single lens or two lenses are viable systems with good optical features and a good stability in image correction. However it involves a relatively significant additional optical mass inside the dewar and thus increases the cool down time of the camera. ONERA is currently exploring a minimalist strategy consisting in giving an imaging function to thin optical plates that are found in conventional dewars. By this way, we could make a cryogenic camera that has the same cool down time as a traditional dewar without an imagery function. Two examples will be presented: the first one is a camera using a dual-band infrared detector made of a lens outside the dewar and a lens inside the cold shield, the later having the main optical power of the system. We were able to design a cold plano-convex lens with a thickness lower than 1mm. The second example is an evolution of a former cryogenic camera called SOIE. We replaced the cold meniscus by a plano-convex Fresnel lens with a decrease of the optical thermal mass of 66%. The performances of both cameras will be compared.

A system is put forward which can automatically measure focus and estimate whether the aerial camera is off-focus and the situation of the factual image plane is in the focus depth range or not. The principle, the hardware composition and the software design are discussed in detail. The system acquires examining-focus information with the optical collimate system, receives images information with CCD camera which can be regarded as optoelectric conversion apparatus, processes data with the center of gravity method, and realizes the axial flow of the CCD camera translation with the grating displacement sensor and the digital readout together. Then, the optimum image situation and the image size can be fixed on. The optimum image situation can be used to judge whether the camera is off-focus, and the image size can be used to calculate the focus. The accurate rate of examining focus can reach almost99.87% and the estimation of off-focus or not accords with experiment result of flight. Use this system, the focus of the lens and the situation of the actual image plane can be judged to accord with the technical standards or not, so that image of high quality can be get with aerial camera.

A measuring system of the focus surface message of bigger aperture aerial camera was described. The image is received by the collimator of long focus and area CCD camera. The location and size of the optimum image were measured effectively by using dynamic scanning and least square method. Therefore, the accurate measurements of the focus of aerial camera lens and the location of the actual imaging surface can be realized in the relative accuracies of 0.1% and 100% respectively.

Lytro, a Silicon Valley start-up, has just launched the world's first consumer light-field camera, which shoots pictures that can be focused long after they're captured, either on the camera itself or online. Lytro promises no more blurry subjects, and no shutter lag waiting for the camera's lens to focus. A software update to the camera, coming soon, will even let you produce 3-D images.

The optical geometry of two adjacent detectors in the focal plane of a scanning millimeter wave imaging system is similar to that of a stereo camera with optical axes of two component cameras which are diverging radially. The perceived image characteristics of the diverging-type stereo camera are analyzed, and they are compared with those of other camera arrangements, such as parallel- and radially converging-types. The distortions induce the image closer to the viewers for the diverging-type while away for the converging. The inducement is more prominent as the camera distance between two component cameras of the stereo camera, especially for the diverging-type.

Reflected-Ultraviolet photography is applied to the evidence of crime, Archaeology, and Dermatology. In the past, Ultraviolet photography was done with standard black-and-white film. Because emulsion of film is more sensitive to near UV light than CCD(Charge Coupled Device) or CMOS(Complementary Metal-Oxide-Semiconductor)of digital camera. In this research, we purpose to improve qulity of ultraviolet photographs and to find out the best alternative digital camera by utilizing a cunsumer digital camera. To achieve theses, we removed IR cutoff filter from digital camera. And by using modified UV pass filter, we verified the increase of image resolution of digital ultraviolet photographs. Also, we analyze reproducibility of digital ultraviolet photographs according to type, size, pixel of image sensor. Furthermore, this research resulted in the development of an practical digital camera system by utilizing a cunsumer digital camera. Eventually, it will contribute to practical use in the various field of digital ultraviolet photographs

Zoom lenses are widely accepted in vision system. However, the use of zoom lenses is not general in close range photogrammetry from the view point of instability by zooming. With the spread of consumer grade digital cameras with integrated zoom lenses, in particular high zooming lens such as 35× were appeared on the market in Japan. In these circumstances, digital photogrammetry using the consumer grade digital cameras is enormously expected in various application fields.There is a large body of literature on the calibration of zoom lenses. However, there is still problem for effective digital photogrammetry using the consumer grade digital cameras. The problem is practical calibration technique of zoom lens. In this paper, a newly calibration technique is proposed based on correction of zoom lens misalignment. In order to evaluate the newly calibration technique of zoom lens, calibration tests were conducted using 5 kinds of consumer grade digital camera (3-5×), 3 kinds of high zooming consumer grade digital camera (12-30×) and digital SLR camera with zoom lens (11×). The results show that the newly calibration technique is simple and stable for all zoom setting.

Photography has an expression technique that lets a person see the main subject closely by shading off background to put the main focus on the main subject, such as a person. However, its depth of field is deep and cannot satisfy the demand of the user to adequately shade off the background of the subject because almost all digital cameras have an imaging element only 1/5 size of that a film camera. Therefore, in this study, a method was developed to change the depth of field of digital camera images to that of film cameras by Using firmware.

An improved panoramic annular camera system with very high spatial bandwidth while at compact size that images the surrounding environment through an annular lens to an image sensor in quasi-real time is described here. The image improvements are realized by using a larger annular lens and a larger CCD array. The flat cylinder perspective method, which is adopted by the annular lens, and the mapping relationship between the three-dimensional object spaces and the two-dimensional annular imageries were investigated. The annular images can be transformed into rectangular by an improved panoramic image restoration method proposed here. The calculating basis of that method is the circular image at 90 ∘ viewing angle in the object space, which is always included in the field of view of annular lenses. As the large format CCD requires a light shutter to make it function properly, a dual-layer twisted nematic liquid crystal box was adopted to switch the incident light on and off as a camera shutter built inside the lens assembly. It was the first attempt, to the best of our knowledge, to extend the usage of a liquid crystal box to the camera as a light shutter. The induced lens resolution degradation by the liquid crystal light shutter is not evident and the supporting experimental results are provided. Subsequent digital image processing methods, which are necessary due to that imperfect liquid crystal light shutter, are described here to suppress the transfer smears occurred on the CCD array. At last, a calibration experiment was set up to verify the image restoration method and several outdoor experiments were taken to demonstrate the high quality and rich information in the result images.

For an inner-focusing 3-groups zoom lens system, this study suggests a new initial design method which applies the process that changes thin lenses into thick ones effectively and quickly, using the hybrid lens system(thin lens+thick lens). In other words, the hybrid lens system is the semi-automatic design process that makes the thin lens of one group change into a thick one while the other groups are composed of thin lenses. Keeping the total power of the system fixed, the power of each group and the distance between principal planes can be fixed. Of course, the other groups composed of thin lenses could be changed into thick lenses sequentially by this process. This design conception results in the 1/4" 5 M inner-focusing 3-groups 2x zoom lens system satisfying the specifications and performances of zoom lens for phone cameras. Also aspherization on lens elements of glass and plastic material enhanced the resolution and reduced the lens size. As a result, we have an ultra-compact inner-focusing 3-groups 2x zoom lens system for a phone camera, with a slim size with TTL of 9.8 mm.

Today, interest in the image processing system is increasing in many areas including engineering, medical informatics and bioinformatics. Technological advances in camera and software fields made them to be a current issue in the determining displacement using non-contact measurement systems. In this study, we measure the displacement of civil structures with image processing method using the laser pointer and camera. For the accuracy of the results, we achieved that the most important points are ensuring stability of the shake table, high number image capturing of digital camera per second, parallelism between the screen platform and the camera vision field., Günümüzde görüntü işleme sistemlerine gösterilen ilgi mühendislik, tıp bilişimi ve biyoenformatik gibi birçok farklı alanda artmaktadır. Kamera ve yazılım alanındaki teknolojik gelişmeler, bu sistemlerin yer değiştirmenin temassız ölçüm sistemleriyle belirlenmesi konusunu gündeme getirmiştir. Bu çalışmada da lazer işaretçi ve kamera kullanılarak görüntü işleme yöntemiyle yapıların yer değiştirmesinin ölçülmesi amaçlanmıştır. Çalışmada, ölçüm sonuçlarının doğruluğu için, sarsma tablasının stabilitesinin sağlanması, dijital kameranın saniyedeki görüntü yakalama sayısının yüksek olması, ekran platformu ile kameranın görüş alanı arasındaki paralellik faktörlerinin en önemli noktalardan olduğu sonucuna varılmıştır.

Fisheye cameras are widely adopted in the back view camera of vehicles and the surveillance camera. Compared to the normal digital cameras, their resolution and image quality are low. In this paper, we propose a method to restore the high resolution images from the fisheye camera by the reconstructed type of super resolution. First, we undistort the fisheye images and regularize these images. Then we super-resolve these regularized images. Blur kernel for super resolution includes the lens blur and the expansion and reduction by the undistortion. The experimental results confirms to the effectiveness of our method which applies to the images captured by the digital camera with fish-eye lens.

The slim design of portable electronic devices (e.g. smartphones) causes a constant need for miniaturized camera systems. This trend pushes the shrinking of opto-electronic, electronic and optical components. While opto- and micro-electronics have made tremendous progress, the technology for the miniaturization of optics still struggles to keep up. The demand for a higher image resolution and large aperture of the lens (both driven by shrinking pixel size) conflict with the need for a short focal length and a simple, compact design. These conditions impose high demands on the fabrication technology, especially when considering that it has to meet one-hundreds of a percent relative accuracy. Wafer-level optics (WLO) fabrication for camera lenses is a promising candidate, enabling high-volume production with low cost. However, the resolution that is currently available with WLO-technology is limited due to material and process control issues. We realized a 720p resolution module by an alternative lens design using a multi aperture scheme which captures different portions of the field of view (FOV) within separated optical channels.

Zoom lens has been developed around lens applications of consumer still camera and TV broadcast cameras from about 1960s. Among, zoom lens as an interchangeable lens of a single-lens camera has made the most significant evolution in technically. In this paper, I describe the change of optical design concept about focusing function in zoom lens including introduction of some topic specific lenses.

This paper introduces motion focus as a complement to conventional camera focusing. We show how a relative shift between the image sensor and lens of a camera offers the ability to focus on specific motion in a scene. Focusing on motion allows the use of a longer exposure time while preventing motion blur of the object of interest. As a result, the object is captured with a significantly improved image quality. We derive a theoretical performance gain and compare it to existing imaging methods. Furthermore, we demonstrate an experimental motion focus implementation using modified off-the-shelf optical image stabilization hardware, which can obtain an effective exposure time extension of a factor of 94.

The effect of vignetting is undesirable in image processing and analysis. It cause fall-off of pixel intensity from centre towards edges of the image. In this paper, we propose a new procedure of fast vignetting reduction based on two images acquired with different camera/lens settings. The change of lens aperture or focal length will also change the effect of vignetting in images. These differences are used to estimate a vignetting function, which is used for vignetting reduction. The obtained image after vignetting reduction is not significantly different from the image without vignetting.

When an object projected on a camera, the shape of the projected object image is governed by the relative position and orientation between object and camera. On the other hand, object radiance, viewing angle and distance at the time of taking picture determine the image brightness of an object. So radiometry and geometry both have an important role to describe an object in an imaging plane. Light Emitting Diode (LED) is a perfect source of illumination, which can also be used for communication. For this purpose, it is necessary to model radiation pattern of LED as well as the geometry of the receiving plane. This paper describe radiometric and geometric camera model for Optical Camera Communications (OCC). Also, this paper analyzes simulated image of LEDs for different position and rotation of the camera.

The tilted assumption, a remnant of analog cameras, is still in use. It seeks to compensate the off squareness of the image plane with the lens axis, but in fact creates a systematic shape alteration by introducing a scale variation in the image, and adds shear with the use of a skew parameter. It results in an image center bias which in turn offsets every single parameter estimate in the camera model. We disclose our own exact solution to the internal camera model, modeling the image plane as a pure projection, our related camera calibration method, and discuss the various improvements resulting from our find in almost every performance aspect of digital imaging.

In this paper, we propose a technique for multiregion autofocusing. The objective is to make the objects of interest at the different distance locations well focused while maintaining the shallow depth of field. Based on the image sharpness analysis of interested regions, we determine the camera's best lens position and largest aperture size such that the depth of field encompasses all objects selected by the user. Thus, in addition to emphasize the objects of interest in photography, our method can also reduce the exposure for image stabilization. Experiments with real scene images are presented.

Conventional cameras capture images with limited depth of field and no depth information. Camera systems have been proposed that enable additional depth information to be captured with the image. These systems reduce the resolution of the captured image or result in reduced sensitivity of the lens. We demonstrate a camera that is able to capture extended depth of field images together with depth information at each single frame while requiring minimal impact on the physical design of the camera or its performance. In this paper we show results with a camera for mobile devices, but this technology (named dual aperture to recall the major change in the camera model) can be applied with even greater effect in larger form factor cameras.

Future cameras are used to "capture the moment" not just the instant when the shutter opens. The moment camera gathers significantly more data than is needed for a single image. This data, coupled with computational photography and user-assisted algorithms, provide powerful new paradigms for image making. The camera constantly records time slices of imagery. Although the input to the moment camera creates a spacetime slab, the moment's output typically consists of a single image. Thus, the processing primarily selects the color for each output pixel given the set of input images in the spacetime slab

We propose a camera that can maintain its thin dimension even when it utilizes a lens with a large focal length to zoom in. Large focal length have made the structure of a conventional camera thick. In this paper, we show how reflective optics prevents a camera from requiring significant thickness. Reflective optics is an inclusive term for optical systems consisting of mirror reflectors or a combination of lenses and mirrors. To demonstrate the concept, we fabricated a double-focus lens. Since this lens has a wide-angle lens inside and a telescopic lens outside, two views from different focal lengths can be obtained by deciding which part of the lens is to be used. We fabricated a micro-mirror structure that has flexible hinges and is actuated by external magnetic fields. The mirror that reflects light through the outside lens also takes the role of a shutter, by blocking light passing through the inside lens when the camera is utilizing the outside lens. By shifting the mirror, the camera can allow light to pass through the inside lens. Thus, the view with the double-focus is selected by actuating the mirror. We demonstrated switching between the two views with our prototype camera.

The stereoscopic camera based on the image formation principle on human eyes and the brain is designed and fabricated by using a CCD and two zoom lenses. As two zoom lenses are separated as 65 mm of the human ocular distance with the wide angle of view of and the variable convergence angle from to , the camera can be operated by the similar binocular parallax as human eyes. In order to take the dynamic stereoscopic picture, a shutter blade for the selection of the left and right images in turns, an X-cube image combiner fur the composition of these two images through the blade, and a CCD with 60 frames per second are used.

A three-dimensional (3D) capture system based on integral imaging with an enhanced viewing zone by using a camera array was developed. The viewing angle of the 3D image can be enlarged depending on the number of cameras consisting of the camera array. The 3D image was captured by using seven high-definition cameras, and converted to be displayed by using a 3D display system with a 4K LCD panel, and it was confirmed that the viewing angle of the 3D image can be enlarged by a factor of 2.5 compared with that of a single camera.

Recently, light field cameras have become popular as cameras with which you can refocus images after having taken pictures. In this paper I report that combination of this light field camera and integral display has useful features for 3D image capture and reconstruction. Refocusing function is based on 3D information contained in light field data and this fact means that a light field camera captures 3D images and encodes them in the 2D sensor plane by micro lens array. This 3D capturing is unique in two points; one is that a light field camera acquires not real 3D object images but 3D image plane compressed in axial direction by the object lens in proportion to ratio of longitudinal and lateral magnification. So when captured 3D image plane is shown on the integral display, the actual 3D image is reconstructed near display screen like an embossed carving. The other point is that the reconstructed image is of higher resolution than density of micro lens. Light filed data by the light field camera basically contain full resolution information not limited by density of micro lens. This implicit resolution in encoded data comes out, when the light field data is decoded by the integral display thorough optical convolutional process.

In this work, three servo motors are used to independently control the aperture, zoom, and focus of our zoom lens. Our goal is to calibrate, efficiently, the camera parameters for all the possible configurations of lens settings. We use a calibration object suitable for zoom lens calibration to deal with the defocusing problem. Instead of calibrating the zoom lens with respect to the three lens settings simultaneously, we perform the monofocal camera calibration, adaptively, over the ranges of the zoom and focus settings while fixing the aperture setting at a preset value. Bilinear interpolation is used to provide the values of the camera parameters for those lens settings where no observations are taken. The adaptive strategy requires the monofocal camera calibration only for the lens settings where the interpolated camera parameters are not accurate enough, and is hence referred to as the calibration-on-demand method. Our experiments show that the proposed calibration-on-demand method can provide accurate camera parameters for all the lens settings of a motorized zoom lens, even though the camera calibration is performed only for a few sampled lens settings.

Research on shooting conditions of 3D program production for natural 3D images has been continued. In the study, it has been shown that orthostereoscopic conditions bring about no inconsistency between depth information from perspective of the lenses and that from binocular parallax. A newly developed 3D camera is based on orthostereoscopic conditions, which result in compactness of the camera (weight 8). At the same time, the new camera has a zooming function and is valuable in many ways, especially sport broadcasting. In this paper, we give an outline of the newly developed 3D HDTV camera and the results of subjective evaluation tests on psychological effects of the images shot by the camera. These tests show that the images shot by this camera are more powerful and comfortable to view than those shot by existing 3D cameras.