226 results about "Calibration matrix" patented technology

An optical see-through (OST) head-mounted display (HMD) uses a calibration matrix having a fixed sub-set of adjustable parameters within all its parameters. Initial values for the calibration matrix are based on a model head. A predefined set of incremental adjustment values is provided for each adjustable parameter. During calibration, the calibration matrix is cycled through its predefined incremental parameter changes, and a virtual object is projected for each incremental change. The resultant projected virtual object is aligned to a reference real object, and the projected virtual object having the best alignment is identified. The setting values of the calibration matrix that resulted in the best aligned virtual object are deemed the final calibration matrix to be used with the OST HMD.

Described herein is a method of calibrating a three-dimensional imaging system. During calibration, a position and an orientation of the three-dimensional imaging system is determined with respect to a first parameter comprising a real world vertical direction (V_w) and to a second parameter comprising an origin of a three-dimensional scene captured by the imaging system. The first and second parameters are used to derive a calibration matrix (M_C2w) which is used to convert measurements from a virtual coordinate system (M_c) of the three-dimensional imaging system into a real coordinate system (M_w) related to the real world. The calibration matrix (M_C2w) is used to rectify measurements prior to signal processing. An inverse calibration matrix (M_w2c) is also determined. Continuous monitoring and adjustment of the setup of the three-dimensional imaging system is carried out and the calibration matrix (M_c2w) and its inverse (M_w2c) are adjusted accordingly.

A method of calibrating a probe mounted on a machine in which the probe has a probe calibration matrix which relates the probe outputs in three orthogonal axes to the machine's X, Y and Z coordinate system. A datum ball mounted on the machine is bi-directionally scanned by the probe in one or more planes. For each plane, the mean direction of two approximate probe vectors in the plane is rotated about an axis orthogonal to that plane until the apparent material condition from the scan in each direction is the same. This process may be iterative. The mean values of the directions of the probe vectors for each plane are rotated, thus forming a corrected probe calibration matrix. The datum ball is preferably bi-directionally scanned in three orthogonal planes.

A view transformation matrix that represents the position/attitude of an HMD is generated based on a signal that represents the position/attitude of the HMD (S602). On the other hand, landmarks and their locations are detected based on a captured picture (S604) and a calibration matrix ΔMc is generated using the detected locations of the landmarks (S605). The position/attitude of the HMD is calibrated using the view transformation matrix and calibration matrix ΔMc generated by the above processes (S606), a picture of a virtual object is generated based on external parameters that represent the position/attitude of the calibrated HMD, and a mixed reality picture is generated (S607). The generated mixed reality picture is displayed in the display section (S609).

The invention discloses an online calibration system and an online calibration method for ununiformity of an LED (light-emitting diode) display screen. The online calibration system and the online calibration method mainly solve problems that an existing test method is only used for testing brightness uniformity, tested brightness uniformity index cannot reflect an overall performance of an LED display screen, and ununiformity calibration cannot be carried out according to tested data. The online calibration method includes steps of acquiring test images displayed by the LED display screen by a camera, and dividing LED lamp points by a method based on background prediction after noise is eliminated; repositioning luminous zones of the lamp points and component pixels of the luminous zones; and then mixing the lamp points to form colors of the pixels, and fitting acquired chromaticity coordinates of the lamp points to form a Gaussian curve after gross errors are eliminated, and solving a mean value of the chromaticity coordinates; substituting the mean value of the chromaticity coordinates into a uniformity evaluation formula to evaluate the uniformity; and finally generating a calibration matrix and performing online real-time online ununiformity calibration point by point. The online calibration method for the ununiformity of the LED display screen is high in precision and efficiency and good in stability, is simple, convenient and feasible, and is capable of being used for testing a uniformity display performance and ununiformity calibration for the LED display screen.

The invention discloses a method and equipment for multi-channel digital sound playback. The user can enjoy multi-channel music calibrated to properly match the user's location. The apparatus includes a sound signal generation unit for generating a digital sound signal from multi-channel sound resource data, and a channel calibration unit for storing a channel calibration matrix set by a control signal generated based on user's position information, using the The stored matrix calibrates the multi-channel sound signal and carries the calibrated sound signal to a plurality of speakers. A multi-channel digital sound playback method includes generating a multi-channel sound signal from multi-channel sound resource data, and setting a channel calibration matrix based on user's position information input by a user and calibrating the multi-channel sound signal using the set matrix Then carry the calibrated multi-channel sound signal to multiple speakers.

A scope navigation apparatus, method and a program embodied computer readable medium for navigating a scope end that is to be inserted into an object. The scope end includes at least one sensor that senses a spatial location of the scope end. An image pickup device records one or more images of a calibration device, which includes a sensor that senses a location of the calibration device. A processor calibrates the images recorded by the image pickup device and corrects for intrinsic and extrinsic parameters using a calibration matrix.

A method and apparatus for multi-cell calibration in a wireless communication system supporting cooperative Multiple Input Multiple Output (MIMO) are provided. Operations of a Base Station (BS) according to the method include transmitting a first message indicating a start of multi-cell sounding calibration to a reference Mobile Station (MS); estimating an uplink channel matrix of the reference MS using pilot symbols received from the reference MS; transmitting pilot symbols for enabling the reference MS to estimate a downlink channel matrix; when receiving downlink channel information of cooperative BSs from the reference MS, transmitting second messages comprising the downlink channel information to the cooperative BSs; and determining a multi-cell calibration matrix using the uplink channel matrix and the downlink channel information received from the reference MS.

The invention relates to an infrared two-point non-uniform calibrating method based on a frame black body field diaphragm, belonging to the field of infrared thermal imaging. The method comprises the following steps of: arranging an automatically-telescopic frame black body field diaphragm on a diaphragm of an infrared thermal imager and performing two-point calibration under a frame to obtain a gain calibration factor and an offset calibration factor of a detection unit under the coverage of a frame black body; acquiring f frames of initially-calibrated images respectively on two scenes to obtain f-1 groups of inter-frame displacement parameters on every scene; and acquiring calibration parameters of f-1 groups of images with inter-frame displacement on an internal detection unit by adopting an algebraic method, and averaging the frames to obtain finial calibration matrixes G and 0 for calibrating the entire field of a subsequent infrared video. The method has the advantages of rapidness, self-adaption and system miniaturization, and can be applied to the fields of designing, production and manufacturing of refrigerating and non-refrigerating infrared focal plane detector thermalimaging systems, satellite infrared thermal imaging systems, infrared alarm systems, scientific researches and the like.

A method for the rapid analysis of the fatty acid components present in a fat and/or oil-containing material is provided wherein the levels and types of fatty acids present in a sample are determined using Fourier Transform Near Infrared (FT-NIR) spectroscopy. The FT-NIR technique is developed by preparing a calibration matrix based on FT-NIR and Gas Chromatography (GC) analysis of known standards, and subsequently using the calibration matrix to analyze the FT-NIR spectral data obtained from a sample to be tested.

A method and apparatus for determining acquisition geometry of an imaging system from a set of calibration matrices for an arbitrary position of the system, a projection matrix makes a point in a 2D image correspond to a point of an object in a space. This matrix is produced for any unspecified position of the system from knowledge of a limited number of pre-computed calibration matrices. For instance, a projection matrix may be computed by interpolating coefficients of calibration matrices and/or applying a transformation with a rigid model defined comprehensively or locally to a particular calibration matrix.

The invention discloses a reciprocity loss compensation method of a 2*2 TDD-MIMO system channel, which mainly solves the problem of channel reciprocity loss caused by in-phase/orthogonal I/Q imbalance in a TDD-MIMO system. In the method, a base station BS and a mobile station MS first measure respectively received direction channels to obtain channel state information CSI of an uplink and a downlink; then converging the CSI of the two links to the BS, and the BS calculates the calibration matrixes respectively used for the BS and the MS; sending the calibration matrix used by the MS to the MS; and when in formal data transmission, the BS and the MS use the respective calibration matrixes to pre-process signals to be sent so as to maintain the channel reciprocity of the uplink and the downlink. The method has the advantages of easiness, good effect and little spending of the system, and is applicable in compensating for the loss of the TDD-MIMO system channel caused by I/Q imbalance.

The utility model relates to a method for calibrating an optical strapdown inertial navigation system based on a two-axis turntable. The method comprises the following six steps: firstly, selecting an error model; secondly, mounting three axles of the optical strapdown inertial navigation system to the two-axis turntable according to the east-north-up direction, and then collecting data after the whole system is powered on and preheated; thirdly, collecting data and storing the data to a calibration matrix according to the twelve positions of east-north-up, west-south-up, north-east-down, south-west-down, up-south-east, up-north-west, down-north-east, down-south-west, south-up-west, north-up-east, south-down-east and north-down-west; fourthly, rotating around the z-axis, the y-axis or the x-axis for 3 minutes at omega of plus or minus 2 degrees per seconds, plus or minus 10 degrees per seconds, plus or minus 30 degrees per seconds, plus or minus 60 degrees per seconds or plus or minus 100 degrees per seconds according to the two positions of east-north-up and north-west-up, and equalizing the output data and storing the average value in the calibration matrix; fifthly, collecting data for 15 minutes at each position of the four positions of east-north-up, west-north-up, north-east-down and south-west-down, and then equalizing the output data and storing the average value in the calibration matrix; and sixthly, using the least square method for calculating the calibration parameters of an accelerometer, and using an analysis method for calculating the calibration parameters of a gyroscope.

The invention discloses a gun camera and dome camera linkage system-based coordinate correlation method. The method includes the following steps that: as for the same scene, monitoring images of a gun camera to be calibrated and a dome camera to be calibrated are acquired; a first scale space image set and a second scale space image set are generated based on the monitoring images; extreme value sampling points are selected from the first scale space image set and the second scale space image set respectively, and a certain number of matching point combinations are screened from different scale space image sets; a certain number of calibration point combinations are further screened from the matching point combinations; a calibration matrix of the monitoring images of the gun camera and the dome camera is acquired according to the coordinates of the calibration point combinations; and pixel points in a second monitoring image, which are corresponding to specified pixel points in a first monitoring image can be determined. According to the prior art, errors exist on a calculated calibration matrix, and as a result, a corresponding relation between the gun camera and the dome camera is not accurate, and the problem of linkage tracking failure may be brought about, while, with the method of the invention adopted, the problem in the prior art can be solved.

A reflective photo device, and electronic apparatus with a built-in camera using the device for providing calorimeter and ambient light sensor functions and the method thereof is provided, in which the built-in camera and a reflective photo device are used to provide the colorimeter and ambient light sensor functions. When the built-in camera provides the calorimeter function, the reflecting hold device is hitched on a display of an electronic device. Therefore, a light beam with color block information emitted from the display is received by the built-in camera via the reflecting operation of the reflective photo device. Thereafter, the electronic apparatus processes the light beam received by the built-in camera based on a reflector compensation matrix and a built-in camera calibration matrix to obtain a color profile of the display.

Disclosed is a system and a method for rectifying stereo images, which are acquired by two cameras, in real-time by using a calibration matrix resulting from camera calibration. The system includes a coordinate generation module; a rectification coordinate generation module; a bilinear interpolation value generation module; a rectification coordinate memory; a bilinear interpolation memory; an image buffer; an rectification module; and a control module. A structure of a hardware system capable of real-time stereo rectification is provided, and the operation results have been verified by implementing a hardware device. The real-time stereo rectification system makes it possible to acquire rectified images in real-time without using a separate computer system or a software program.

The invention discloses a non-local mean value image denoising method based on a filter window and parameter adaption. According to the invention, firstly, noise is detected, and a noise calibration matrix is established according to a detection result; the size of the noise calibration matrix is consistent with the size of an image, and the matrix value at a corresponding position of each noise point is set to be 1, and the matrix value at a corresponding position of each non-noise point is set to be 0. Then, each pixel of a noise image is successively taken as a reference point, and centric to the point, a predetermined number of non-noise reference points are taken in a counterclockwise direction to be involved in computation. Finally adaptive weighting parameters are determined according to the locations of the reference points, and a weighted result is calculated and a restored pixel value is obtained; the corresponding element in the noise calibration matrix is set to be 0 and the pixel point after denoising can be used as a reference point of other noise points. Compared with traditional image denoising methods, the method provided by the invention is added with the noise detection and noise point screening, thus improving algorithm accuracy, changing a reference point selection window and improving algorithm adaptability.

The invention is applicable to the image processing field, and provides a panoramic image or video horizontal calibration method, a panoramic image or video horizontal calibration system and a portable terminal. The method comprises steps: images or video frames of two circles after imaging of two cameras with opposite photographing directions are received; a horizontal calibration matrix in the case of photographing is acquired; and according to the horizontal calibration matrix, the images or the video frames of two circles are pasted to a left hemisphere surface and a right hemisphere surface of a spherical panoramic mathematical model in a UV mapping mode, and thus, the panoramic image or the video frame pasted to the spherical panoramic mathematical model is horizontal. When an image or a video frame photographed by a panoramic camera is not horizontal, the panoramic image or the video frame pasted to the spherical panoramic mathematical model is still horizontal.