931 results about "Distortion correction" patented technology

The Electric Power Converter has the qualifications for an uninterruptable power supply, battery management, energy conversion, micro-grid formation, Power Factor Correction including Total Harmonic Distortion correction in real time. Uninterruptable power supply's use is for always-on, real-time, all-time, reduced distortion with functions of load reduction and management during peak load events. The Electric Power Converter as well has the ability to provide maintenance for most types of batteries including charging and discharge regiments to increase the overall lifetime of a battery, the maintenance, incorporating restorative functions that can refurbish dead batteries or can further increase the overall efficiency and useful function of weaker/aged/defective batteries. Energy conversion capabilities allow for the conversion of AC or DC to AC or DC with high efficiency and ability to actively vary the frequency in accordance to the required parameters. The Electric Power Converter is able to establish and sustain a micro-grid with multiple and varying sources of power generation and load conditions. The Electric Power Converter is achieving dynamic, real-time, interactive Power Factor Correction (PFC) function with advanced voltage harmonic distortion correction with a high efficiency ratio. The Electric Power converter is designed to function with the emerging Smart Grid technologies and provide an overall higher level of operating efficiency and higher quality of electrical power.

A method and system for automated production of stereoscopic and animated images and hardcopies can utilize a light-sensitive lenticular material employing a conventional or non-conventional photographic emulsion or an instant-developing material. An automated printer can produce autostereoscopic and animated hardcopies in multiple formats from digital and non-digital sources, including single images, stereopairs, and multiple-image sets of negatives, transparencies, or prints. The printer, which includes a projection device and a material plate that can rotate around two perpendicular axes, can utilize software to automate viewing angle calculation, printer control, multiple-image alignment, distortion correction, and image processing and conversion. A digital camera can capture stereoscopic and animated images and record them digitally or on photographic film. A non-digital camera can record stereoscopic and animated images directly onto light-sensitive lenticular material employing a conventional or non-conventional photographic emulsion or an instant-developing material. The printer and cameras can utilize autostereoscopic monitors to preview parallax.

The invention provides a method for improving image stitching accuracy and a device for implementing the same, which apply to the multi-camera system for wide-angle image generation. Lens distortion causes mismatches of the features in the overlapping region of the images captured by the multi-camera system. As a result, the mismatches on the stitched wide-angle image are visible. The method and device for improving image stitching accuracy correct the lens distortion before stitching the images captured by the multi-camera system, so that the features in the overlapping region are matched and a seamless wide-angle image is generated by the stitching engine.

A signal processing method and apparatus capable of correcting signal distortion introduced by an RF power amplifier is disclosed, which includes the use of a buffer to store a plurality of samples representing at least a portion of an input signal intended for amplification by the RF power amplifier, the use of a self-receiver to receive an output signal generated by the RF power amplifier, the use of a synchronization unit to determine, as a matching input sample, which of the stored plurality of samples corresponds most closely to the output signal, and the use of a predistortion unit to selectively apply a distortion correction function to the input signal prior to amplification by the RF power amplifier in which the distortion correction function being derived from a relationship between the matching input sample and the output signal. This permits more precise and updateable determination of the delays involved in the RF modulation and amplification stages of the amplifier and the self-receiver, thus allowing for more precise and aggressive adaptive predistortion to be used. A phase offset correction is optionally provided to correct a phase offset in the realized sample of the output signal relative to the matching input symbol. Additionally, a sampling phase error correction unit may be provided to generate sampling alteration information to an analog-to-digital converter to cause such analog-to-digital converter to selectively alter sampling of the output signal.

Pages of books are copied without distortion due to curvature of the page near the book binding or the distortion in a copied page is corrected using the spacing of equidistant bars on tape strips applied to the top and bottom edges of a page before copying. The tape is preferably transparent and rather narrow and easily attached to a page to be copied. The first step in the distortion correction procedure is to locate the bars at the top and bottom of the page. The distortion of the spacing between the imaged bars is computed based on the known distance between the equidistant bars. The computed distortion of the spacing is then input to a distortion correction algorithm. The output of the distortion correction algorithm generates a corrected image. This image may also optionally delete the bars so that they are not printed in the copy. The corrected image is then copied.

The invention provides a binocular camera-based panoramic image splicing method. According to the method, a binocular camera is arranged at a certain point of view in the space, the binocular camera completes photographing for once and obtains two fisheye images; a traditional algorithm is improved according to the defect of insufficient distortion correction capacity of a latitude-longitude correction method in a horizontal direction; corrected images are projected into the same coordinate system through using a spherical surface orthographic projection method, so that the fast correction of the fisheye images can be realized; feature points in an overlapping area of the two projected images are extracted based on an SIFT feature point detection method; the search strategy of a K-D tree is adopted to search Euclidean nearest neighbor distances of the feature points, so that feature point matching can be performed; an RANSAC (random sample consensus) algorithm is used to perform de-noising on the feature points and eliminate mismatching points, so that image splicing can be completed; and a linear fusion method is adopted to fuse spliced images, and therefore, color and scene change bluntness in an image transition area can be avoided.

The invention is suitable to the independent motion vehicles environment sensation monocular visual navigation method, first surveys the camera distortion parameter, puts the camera on the independent motion vehicles, determines transformation relation from image plane coordinate system to world coordinate system; then records current car body posture, gathers the picture in the current car body visible scope, feedback the picture to the picture operation contact surface in order to definite the walk mode of the car body and do distortion correction on the gathering picture, select the path and the path spot on the path, according to the coordinates transformation relations under the world coordinate system put the current position and choice path result to the car body and demonstrate on the graph operation contact surface by the car body width; the car body walks according to the independently evades bonds or the way track way till the current visible scope last way spot, and then circling start from the gather picture to the final object point. The invention applies the monocular measuring technique in the unknown environment the visual navigation.

The invention relates to a three-dimensional intelligent video monitoring method, which comprises the following specific steps of: firstly, performing three-dimensional modeling on an actual monitoring area and displaying a three-dimensional virtual scene corresponding to the actual monitoring area by using software; secondly, calibrating a camera to acquire the internal and external parameters and distortion correction parameter of the camera and establishing a two-dimensional image and three-dimensional space one-to-one mapping relational model; thirdly, intelligently analyzing a monitoring video acquired by the camera to acquire moving target information comprising a target category, a moving path and the like; fourthly, positioning target information in a two-dimensional image in a three-dimensional space and displaying the target information in the three-dimensional virtual scene in real time; and finally, storing a target two-dimensional video and the moving path in the three-dimensional space synchronously for system retrieval and playback. In the method, a two-dimensional moving target is positioned in the three-dimensional virtual scene by fully utilizing the real three-dimensional space feeling of the three-dimensional virtual scene, so that the ability of monitoring personnel of quickly positioning and processing an alarm event is improved and the workload of the monitoring personnel is effectively relieved.

An image processing apparatus includes stereo cameras and detects a distance to a target around a vehicle. The image processing apparatus includes sensors installed in the vehicle; determines a vehicle situation by combining detection signals of the sensors and switches from image data of a stereo camera for driving assistance to image data of a stereo camera for door opening/closing assistance; carries out distortion corrections that are unique to the plural stereo cameras respectively on the selected image data so that correlation calculation common to the plural stereo cameras can be carried out; carries out the correlation calculation on two sets of image data of the single stereo camera; and detects the distance to the target by using a calculation result of the correlation calculation.

The invention relates to a system capable of realizing immersive virtual reality across mobile platforms. A DirectX3D rendering technology is adopted to perform distortion correction and distortion scale on images rendered by virtual three-dimensional scenes via a Pixel Shader, the images are segmented and drawn on left-eye and right-eye screens of HMD equipment, and a refresh frequency of more than 60 frames per second is kept; position information and facing information of the HMD equipment are acquired from a sensor and used for head tracking, and coordinate and rotating quaternion information are fed back to an application program via a message interface; and interaction between a client end and a server end is realized by adopting a wireless communication technology. The system provided by the invention has the advantages that one product only needs to be developed for once, reality is enhanced, virtual objects not existing in the real environment are generated via a computer graphic technology and a visualization technology, the virtual objects are accurately 'placed' in the real environment via the sensing technology and are integrally mixed with the real environment by the aid of displaying equipment.

The invention discloses a panorama parking calibration method and a device, and an automatic calibration method, wherein the panorama parking calibration method comprises the steps of obtaining pictures which is captured by an automobile camera; using default parameters of a panorama parking system to generate an aerial view; distinguishing tag blocks on the aerial view; distinguishing controlling points according to the tag blocks; obtaining actual positions and ideal positions of the controlling points, wherein the controlling points are intersection points of lines and distributed in a net shape, and the ideal positions are appointed positions in the aerial view; and optimizing by utilizing difference between the actual positions and the ideal positions of each controlling point in the aerial view and obtaining lens distortion correction parameters and perspective transformation parameters of a wind-angle camera which corresponds to the aerial view. The area of the tag blocks is greater than that of the intersection points and is easy to distinguish. A light color is adopted on distinguish strips and a deep color is adopted on a carrier so as to reduce effects which are caused by reflect light, an absolute coordinate of a calibration pattern on a coordinate system is positioned and calibrated accurately, and a success rate of calibration is improved.

A digital camera includes a distortion correction section, which is composed of a focal length determining section, a distortion evaluation section and a correction amount calculating section. The focal length determining section evaluates a focal length at the time of image capture. Based on the focal length, the distortion evaluation section evaluates the magnitude of wide-angle distortion and optical distortion in a captured image. Based on this evaluation, the distortion correction section selects an appropriate coefficient from an optical distortion correction coefficient table or a wide-angle distortion correction coefficient table. Using the selected coefficient, the correction amount calculating section applies a coordinate transform processing to cause positive or negative distortion to the captured image, and corrects the wide-angle distortion or the optical distortion.

A projection set of geodesic lines which are parallel with each other on a curved surface of a paper face is extracted from an image in which a paper face has been imaged by an image-pickup device, using the paper face contents as a clue; and also a projection set of ruling lines which form a ruled surface corresponding to the curved surface of the paper face is extracted from the projection set of geodesic lines. Then, the curved surface of the paper face is estimated from the projection set of the geodesic lines and ruling lines, and distortion of the image is corrected based on this curved surface of the paper face. If this is done, correspondence with various types of diverse distortions becomes possible, and distortion correction can be performed even when only one part of the paper face appears in the image.

An image processing apparatus has a distortion correction processing unit. The image processing apparatus has a distortion correcting range calculating unit that calculates an input image range necessary for distortion correction processing of the distortion correction processing unit. Thus, the corrected image (output image) obtained by the distortion correction processing can be outputted without overs and shorts for the image output range. The distortion is corrected by effectively using input (picked-up) image data, serving as the original data. Further, the distortion including the pincushion distortion, the barrel distortion, and the curvilinear distortion is effectively corrected.

The invention relates to a traffic signal light intelligent control system and a control method thereof, which belong to the technical field of intelligent traffic; the system comprises four CCD camera heads, a signal processor and a controller; and the method comprises the following steps: establishing a coordinate system and the transformation relation thereof; sequentially carrying out distortion correction, sharpening and perspective transformation on a traffic flow image; extracting edges of a vehicle image and filtering out lane lines and traffic sign arrows in the image; cutting the image; carrying out edge projection for obtaining pixel coordinates which correspond to the queue length of vehicles waiting to pass on each type of lane in each direction under the computer image coordinate system; calculating the actual queue length of the vehicles waiting to pass; obtaining time required for leading all the vehicles on each type of the lane in each direction to pass; and controlling the opening and the closing of a traffic signal light according to the time of leading all the vehicles to pass. The traffic signal light intelligent control system can control the opening time and the closing time of the traffic signal light in a high-efficient and energy-saving manner, thereby providing a scientific information base for realizing the urban intelligent traffic.

Systems and methods of controlling an uninterruptible power supply are provided. The uninterruptible power supply includes an input to receive input power, and an output to provide power to a load. The uninterruptible power supply also includes an inverter, a bypass switch, and a controller. The inverter is coupled with the input and with the output, and the bypass switch can provide the input power at the output in a bypass mode of operation. The controller is coupled with the inverter and the bypass switch. The controller can activate the bypass switch in a first configuration to provide the input power at the output during a first half of a cycle of an input voltage waveform, and can activate the bypass switch in a second configuration to provide the input power at the output during a second half of the cycle. With the inverter active during bypass operation, the inverter can more quickly provide output power upon the loss of bypass power, and can provide near unity power factor correction and harmonic distortion correction.

The invention discloses a parameter calibration method. The method comprises steps of acquiring a calibration template image which is obtained by photographing of a calibration template image; performing corner detection for the calibration template image so as to extract an image corner; calculating radial distortion parameters in accordance with the extracted image corner; performing radial distortion correction in accordance with the calculated radial distortion parameters so as to reconstruct a distortion correction image; and according to a perspective projection relation of the calibration template and the reconstructed distortion correction image, calculating internal parameters and external parameters so as to achieve parameter calibration, wherein internal parameters and external parameters comprise internal parameter matrixes, rotating vectors and translation vectors. The invention also provides a parameter calibration device. The method and the device can be applied to parameter calibration of imaging devices such as video cameras or cameras under the condition of high distortion, the operation is simple and the precision is high.

The invention relates to a fish eye lens calibration and fish eye image distortion correction method which belongs to the field of digital image processing and is very suitable for occasions of vision navigation, mobile monitoring and so on. Since imaging using a large wide angle will cause serious distortion, generally, imaging correction is needed to facilitate human eye observation. The method provided by the invention is mainly technically characterized by establishing a space coordinate system 1 and employing a least square curve-fitting method to calibrate a fish eye image to determine the center andthe radius of a fish eye lens, establishing a cylindrical projection model in a space coordinate system UV, and setting one-to-one relationships among an image point q2 of the fish eye image, a point q1 on object sphere and a point q projected on a cylinder, wherein q1 is in vertical projection relation with a bottom plane on which q2 is located and line q1q parallels to line oq2, thus achieving the purpose of fish eye image correction.

The invention belongs to the field of digital image processing and discloses a fisheye image correction method after calibration conducted by a fisheye lens. The method includes the steps that firstly, a complete fisheye camera projection and distortion model is established and is a commonly-used fisheye model, a self-made planer calibration board and the commonly-used fisheye model are used for calibrating model parameters of a fisheye camera, and the calibrated lens distortion parameters are used for restoring circular distortion fisheye images to perspective images meeting the requirements for the human eye visual effect. The fisheye lens calibration and fisheye distortion correction method based on a planar checkerboard is quite suitable for occasions such as visual navigation and mobile monitoring. The method is suitable for the circular fisheye images and incomplete fisheye images can be corrected as well.

A graphics system comprises pixel calculation units and a sample buffer which stores a two-dimensional field of samples. Each pixel calculation unit selects positions in the two-dimensional field at which pixel values (e.g. red, green, blue) are computed. The pixel computation positions are selected to compensate for image distortions introduced by a display device and/or display surface. Non-uniformities in a viewer's perceived intensity distribution from a display surface (e.g. hot spots, overlap brightness) are corrected by appropriately scaling pixel values prior to transmission to display devices. Two or more sets of pixel calculation units driving two or more display devices adjust their respective pixel computation centers to align the edges of two or more displayed images. Physical barriers prevent light spillage at the interface between any two of the display images. Separate pixel computation positions may be used for distinct colors to compensate for color distortions.

The present invention provides a Satellite-bone camera space image distortion correction method based on the stellar map matching, the stellar point on the image is used as referecen point, achieving the distortion correction, including following steps: (1)image segmentation, extracting the stellar facula in the image; (2) calculating areal coordinates of each facula by the centroid method, as a real coordinate; (3) processing pre-correction according to the deformation parameter obtained by the ground standardization of the camera; (4) processing stellar map matching by single frame or multiple frames Hausdorff distance stellar map matching method, calculating academic coordinate corresponding to the practical coordinate; (5) calculating deformation parameter of the image by the corresponding relation between the practical coordinate and the academic coordinate; (6) obtaining corrected image by the three steps fitting of a polynomial and interpolation method. In addition, the invention aiming at correctoon impact of the camera plain shaft point system error, provides a adaptive compensation method. The invention has small operation, evident image correcting effect, and effectively preventing the impact of the correction caused by the image noise and the input system error.

An improved, adaptive optics control system having a signal-to-noise ratio-tuned wavefront corrector is disclosed. The system comprises a wavefront corrector, a wavefront sensor, a wavefront reconstructor and a wavefront controller. The wavefront corrector has a surface controlled by a plurality of actuators. The wavefront slope sensor has a subaperture separation mechanism for defining a plurality of subapertures through which the distorted wavefront can pass, each subaperture corresponding to an actuator of the wavefront corrector. The wavefront slope sensor produces a wavefront sensor output signal for each subaperture indicative of the distortion of the wavefront. The wavefront reconstructor is adapted to receive the wavefront sensor output signals and calculate corresponding phase estimates based thereon, each phase estimate having a signal-to-noise ratio. The wavefront reconstructor generates a plurality of correction signals to be applied to each of the actuators of the wavefront corrector, each correction signal having a bandwidth. The wavefront controller is adapted to selectively adjust the bandwidth of each correction signal based on the signal-to-noise ratio of the corresponding phase estimate of the actuator to which it is to be applied. A method of optical wavefront distortion correction is also disclosed.

Distortion data discretely stored in a distortion data memory 8 are read out by a selector 9 and fed to a signal processor 5. For each coordinate position, the signal processor 5 calculates an approximation formula representing an image height-distortion curve based on the distortion data fed thereto, and performs distortion correction based on the approximation formula.

The present invention provides a three-dimensional image measuring apparatus and method capable of measuring projections and depressions on a surface of an object with fine precision, as well as ensuring stable convergence, even for stereo images with significant project distortion. The apparatus includes an area setting section 56 for setting a reference area 57 in one image 53 of a pair of stereo images 46 and a search area 58 in the other image 54 in a position corresponding to the reference area 57, a search image distortion correcting section 62 for applying an image distortion correction to either one of the one image 53 or the other image 54 according to the positional relationship between the reference area 57 and the search area 58 corresponding to the reference area 57, and an area shape measuring section 66 for measuring a shape of a measuring object 41 photographed in the stereo images 46 based on the reference area 57 in the one image 53 and the search area 58 in the other image 54, either one of which has been corrected by the search image distortion correcting section 62.

An image processing apparatus applied to a digital camera, includes: a frame memory that inputs and stores, via a bus, image data obtained by capturing an optical image through an optical system by a CCD; a first data-order converting unit that reads and inputs the image data from the frame memory in units of a block in the row direction, and converts and outputs the image data in the column direction; an image processing unit that is connected to the first data-order converting unit for pipeline processing and performs image processing; a distortion correction processing unit that is connected to the image processing unit for pipeline processing and performs the distortion correction processing; and a second data-order converting unit that is connected to the distortion correction processing unit for pipeline processing, returns block data in the column direction into that in the row direction, and outputs the converted data to the frame memory.

A completely differential approach to correcting duty-cycle distortions of a differential clock signal propagating through a differential amplifier. A duty-cycle distortion correction (DCDC) differential amplifier circuit/device is provided with a differential amplifier whose output wires are coupled to a correction circuit. The correction circuit comprises a differential low pass filter and a differential correction amplifier. The differential correction amplifier's output is dotted back into the output of the amplifier. The differential output of the amplifier is passed through the low pass filter, which provides differential DC output signals that triggers respective correction amplifier transistors to generate an inverted correction current that is added back to respective differential output pulse. The DCDC differential amplifier provides a completely differential approach to correction of duty-cycle distortions within the differential output.

The invention discloses an anti-counterfeiting fingerprint identification device and an anti-counterfeiting fingerprint identification method. The device is provided with a sense control unit which comprises a CapSenseSigma-Delta (CSD) chip, wherein the CSD sense chip is connected with a conductive film. Fingerprints of living organisms are judged by recording an increment in the CSD sense chip and summating numeric codes converted by a modulator. The fingerprint identification method comprises the following steps in turn: 1) initializing; 2) circuit self-checking; 3) performing a corresponding program according to information input by a user; 4) judging whether to communicate; 5) acquiring image data; and 6) comparing registered users. The device of the invention has low cost, can outputa signal by touching lightly, does not need to adopt any distortion correction optical element, and can reduce manufacturing cost and realize miniaturization; the linear distortion relationship obtained by comparing an acquired fingerprint image with an actual fingerprint image can be corrected by software; and therefore, the device has the advantages of high quality of acquired optical imaging image, high fingerprint identification reliability, low error identification rate, good effect on anti-counterfeiting fingerprints, simple structure and low power consumption.

The specification and drawings present a new method, system, apparatus and software product for correcting a geometrical distortion of an image using a hybrid interpolation technique by a digital image processor. After calculating corrected coordinates of pixels in the image, the interpolation of color components of the pixels can be performed by using the corrected coordinates, wherein at least one color component is interpolated using a quality interpolator which is different from quality interpolators used for other color components.

The invention discloses a calibration method and device used for a laser processing system. The calibration method includes the steps that firstly, a lens in a galvanometer is controlled to be adjusted according to a calibration picture which is edited in advance, a laser device is driven, a laser beam generated by the laser device is made to penetrate through the galvanometer, and the calibration picture is etched on marking paper which is placed on a processing platform in advance; secondly, an image, photographed by a camera, of the processing platform is obtained, and the image includes the calibration picture; thirdly, distortion correction is conducted according to the image and the calibration picture etched on the marking paper, and the corresponding relation between an image coordinate system and a galvanometer coordinate system is obtained. According to the calibration method and device used for the laser processing system, distortion correction is achieved through the calibration picture on the marking paper, a target does not need to be used, cost is saved under the premise that precision is ensured, and the calibration operation is simplified.

A projector includes an image projection section, a sensor that senses a projected first calibration image at a low resolution and generates first sensing information, senses the first calibration image at a high resolution and generates third sensing information, and senses a second calibration image at a high resolution and generates second sensing information, a projection area detection section that generates projection area information, based on the first and second sensing information, a projection-target area detection section that generates projection-target area information, based on the first, second, and third sensing information, and an image distortion correction section that corrects distortion of an image projected by the image projection section, based on the projection area information and the projection-target area information.