126 results about "Normalized correlation" patented technology

The present invention relates to a method and device for improving concealment of frame erasure caused by frames of an encoded sound signal erased during transmission from an encoder (106) to a decoder (110), and for accelerating recovery of the decoder after non erased frames of the encoded sound signal have been received. For that purpose, concealment/recovery parameters are determined in the encoder or decoder. When determined in the encoder (106), the concealment/recovery parameters are transmitted to the decoder (110). In the decoder, erasure frame concealment and decoder recovery is conducted in response to the concealment/recovery parameters. The concealment/recovery parameters may be selected from the group consisting of: a signal classification parameter, an energy information parameter and a phase information parameter. The determination of the concealment/recovery parameters comprises classifying the successive frames of the encoded sound signal as unvoiced, unvoiced transition, voiced transition, voiced, or onset, and this classification is determined on the basis of at least a part of the following parameters: a normalized correlation parameter, a spectral tilt parameter, a signal-to-noise ratio parameter, a pitch stability parameter, a relative frame energy parameter, and a zero crossing parameter.

A method and system for refining an estimated pitch period estimate based on a coarse pitch useful for performing frame loss concealment in an audio decoder as well as for other applications. A normalized correlation at the coarse pitch lag is computed and used as the current best candidate. The normalized correlation is then evaluated at the midpoint of the refinement pitch range on either side of the current best candidate. If the normalized correlation at either midpoint is greater than the current best lag, the midpoint with the maximum correlation is selected as the current best lag. After each iteration, the refinement range is decreased by a factor of two and centered on the current best lag. This bisectional search continues until the pitch has been refined to an acceptable tolerance or until the refinement range has been exhausted. During each step of the bisectional pitch refinement, the signal is decimated to reduce the complexity of computing the normalized correlation.

The invention provides a method for tracing the position and pose of a 3D human face in a video sequence. In the method, based on the principal component analysis, by using a deformable 3D grid model, minimizing the distance between a key point on the grid model and a corresponding key point on an input image, the model can fit the head figure of a user; the human face texture can be obtained by using the 3D model at an initial phase, so as to render human face images under different poses; the feature points can be selected in the rendered images, and a corresponding position can be searched on the input image; the matching faults can be removed by using a random sampling mode; then, mode pose changed parameters can be estimated according to the corresponding relationship between the feature points, so as to update a hypothetical state; finally, a distance between the rendered image and an actual image can be calculated by using the average normalized correlation algorithm, so as to calculate a hypothetical weight. Experiments show that the method can effectively trace the pose of the 3D head in the video.

The invention discloses a method for timing and synchronizing wireless communication, a method for searching districts and a system thereof. The method fully utilizes the time domain repetitiveness of a main synchronizing signal in a 5ms period and comprises: firstly, adopting predetermined step length sliding time domain cross-correlation to realize blind timing coarse synchronization with low complexity and without local synchronizing signal reconstruction, simultaneously, using normalized correlation processing to resist strong interference, finally, realizing timing fine synchronization with high precision, and correcting receiver integer multiple residual frequency deviation simultaneously. The method can realize timing and synchronization rapidly and accurately in particular in environment with low signal to interference and noise ratio, thereby realizing district searching in a long term evolution wireless communication system. The method can realize downlink timing and synchronization when the signal quality is in the sensitivity position of a terminal receiver and in the environment with strong interference.

The invention discloses a method for automatically registering scanned document images, which comprises the following five steps: detection by using improved characteristic points, the coarse estimation of a rotation parameter, the coarse matching of characteristic points, the elimination of the erroneous matching characteristic points, and precise matching. Concretely, the five steps comprise: detecting the characteristic points of a standard scanned document image and a scanned document image to be matched by using the improved characteristic-point detection algorithm; estimating the primary rotation angle of the scanned document image to be matched relative to the standard scanned document image according to the positions of the characteristic points; calculating matched characteristic point pairs of the characteristic points in the standard scanned document image and the scanned document image subjected to primary rotation by using a normalized correlation algorithm; eliminating the erroneous matching by using an improved random sample consensus robust algorithm; and calculating the matching parameter between the standard scanned document image and the coarsely-rotated scanned document image to be matched according to the positions of the precise matching point pairs searched from an eight neighborhood, and making the parameter act on the coarsely-rotated scanned document image to be matched so as to obtain the registered image.

With an object of solving problems existing in the prior art, the invention provides a fully automatic calibration method for a high performance camera under a complicated background. The method is combined with a Robust's checkerboard corner detection method, and two groups of checkerboards corners are adopted to serve as filters on the basis of the characteristics of the corners to filter marker images. Eight filters of two types are reduced to four filters of two types, which means that the wave processing amount halves and therefore, the calibration speed increases. Further, the method utilizes a Zhang's camera calibration method to mark the camera calibration parameters. The method utilizes the marked camera calibration parameters to standardize images to be corrected, and a normalized correlation of the standardized images is calculated, and then sub-pixel precision checkerboard corners are obtained. The method then re-projects the coordinate of the checkerboard corners onto image space to obtain a precise coordinate of the corner image. The newly obtained coordinate of the corners is then substituted into the Zhang's calibration method to obtain new computed camera parameters. By repeating the above steps, a performer can obtain highly precise camera parameters. According to the embodiments of the invention, it is possible for a performer to complete automatic corner detection and camera calibration without having to resort to human-machine interactive operations.

The present invention provides an auxiliary berthing method and system for a vessel. Position information of a vessel relative to a berth is determined by a solar blind ultraviolet imaging method; meanwhile, by a GPS method, an attitude angle of the vessel relative to the berth is determined by at least two GPS receivers. Thus, the vessel can be berthed safely when getting close to the shore at low visibility. Further, in the method and device of the present invention, it can be preferable to integrate coordinate data and angle data received by a solar blind ultraviolet imaging module and GPS signal receiving modules by a normalized correlation algorithm and a data fusion algorithm, so as to improve the positioning accuracy.

The invention relates to an anisotropic reverse time migration method for a quasi-P wave equation in a transverse isotropy with a vertical axis of symmetry (VTI) medium. The method comprises the following steps of: (1) performing discrete differentiation on a first-order quasi-P wave equation in a two-dimensional VTI medium and a perfect matched layer (PML) absorption layer boundary equation by adopting staggered meshes to obtain high-order difference formats of forward continuation and reverse continuation of the two equations; (2) performing numeric calculation to obtain a forwards-continued wave field of a shot point and a reverse time continued wave field of a receiver point, and performing normalized correlation operation on the two wave fields to obtain a migration imaging result of each imaging point in a model; and (3) extracting common imaging point gathers from migration results to obtain a final migration profile. By the method, a problem about the migration imaging of intensive transverse speed variation and a high dip angle stratum can be solved; and the influence of anisotropy of the medium is also taken into account, and the good imaging effect of longitudinal wave data acquired from an anisotropic region can be achieved by an anisotropy-theory-based migration method.

A system and method for recognizing markers on, e.g., a PCB (printed circuit board). In one aspect, a system for recognizing a marker in an image comprises an image capture module (14) for extracting image features associated with an input image of a ROI (region of interest) captured through a lens 15, an image processor (16) comprising a first marker recognition processor (17) for recognizing a marker in the input image based on a normalized correlation and a second marker recognition processor (18) for recognizing a marker in the input image based on gray value histograms; a training module 19 for building template images and histograms that are used by the image processor (16) to detect a marker in the input image and a database (20) for indexing and storing trained template images and trained histograms.

Methods and apparatus for video object segmentation are provided, suitable for use in a super-resolution system. The method comprises alignment of frames of a video sequence, pixel alignment to generate initial foreground masks using a similarity metric, consensus filtering to generate an intermediate foreground mask, and refinement of the mask using spatio-temporal information from the video sequence. In various embodiments, the similarity metric is computed using a sum of squared differences approach, a correlation, or a modified normalized correlation metric. Soft thresholding of the similarity metric is also used in one embodiment of the present principles. Weighting factors are also applied to certain critical frames in the consensus filtering stage in one embodiment using the present principles.

The invention discloses a real-time visual target tracking method based on light streams. The method includes: screening feature points rich in textural features, and tracking the feature points between every two frames of images to obtain feature point matching relations; filtering the feature points with large matching errors through various filter algorithms such as normalized correlation coefficients, forward-reverse tracking errors and random consistency detection to retain most reliable feature points so as to obtain the target motion speed in images; using the target motion speed as observation quantity, and estimating through Kalman filtering to generate the target position. Compared with a tracking algorithm, the method has the advantages that the method is unaffected by light, the target can be stably tracked under the conditions that the target moves, a camera moves, the target is blocked for a short term and the like. The method is high in calculation efficiency, and the tracking algorithm is verified for the first time on an ARM platform.

A system for autonomous tracking of aerial targets in real space. The imaging means captures and aligns first and second images. A normalized correlation operation initiates a process for producing a resultant image including blobs corresponding to elements in the real space, despite the presence of a homogenous aerial background. One of the blobs is analyzed, classified, and tracked as a target.

The invention relates to a method for realizing a color image digital watermark for certificate anti-counterfeiting and belongs to the technical field of anti-counterfeiting and information security. The technical scheme comprises the following steps of: 1, converting an RGB color space of a color image to an L*a*b* color space; 2, encoding and modulating readable watermark information to generate a colored noise watermark mode; 3, taking an increasing function related to a gradient modulus as a visual control factor; 4, embedding a watermark into an L* luminance component of the L*a*b* color space; 5, performing predictive filtering pretreatment on a watermark image before extracting the watermark and then extracting the watermark by a normalized correlation method; and 6, decoding bits of the extracted watermark into the readable watermark information. The method of the invention improves the correct extraction rate of watermark signals. The scheme has high robustness for resisting printing and scanning attack and can be widely used for the anti-counterfeiting of various certificates.

The invention relates to an intelligent-texture anti-counterfeiting method based on perceptual hashing. A first step is characterized in that image characteristic extraction is performed, which comprises that (1) a perceptual hashing algorithm is used to process an image so as to obtain one visual characteristic vector V (j) of an original texture image; (2) a user uses a mobile phone to scan the texture image to be tested and upload to a server, the perceptual hashing algorithm is used to process the image to be tested and the visual characteristic vector V ' (j) of the image to be tested is acquired. A second step is characterized in that image discrimination is performed, which comprises (3) a normalized correlation coefficient NC value between the visual characteristic vector V (j) of the original texture image and the visual characteristic vector V ' (j) of the image to be tested is acquired; (4) the obtained NC value is returned to the mobile phone of the user. An experiment proves that the method of the invention possesses a strong conventional attack resistance capability and a geometric attack resistance capability. A problem of automatically discriminating the texture image is solved. An intelligent texture anti-counterfeiting technology is realized. Discrimination accuracy is high and a speed is fast.

A signal detection scheme is provided. According to the provided signal detection scheme, a received signal is correlated in a frequency domain with a reference signal. Additionally, the reception power of the received signal is calculated and the correlation value is normalized with the reception power. Therefore, a single threshold value may be used regardless of the reception power of the received signal when comparing the correlation between the received signal and the reference signal with the threshold value in order to determine whether the received signal is a desired signal or noise.

The invention discloses a method for identifying and positioning spacers of transmission lines by the aid of a video image processing technology, and belongs to the technical field of digital video image processing and online monitoring for transmission lines. The method includes positioning target areas of images and positioning centers of the spacers by processes for normalizing the original images, acquiring direction fields, matching templates and the like; computing the direction fields of the images by a square-gradient algorithm when the target areas are positioned, and combining the direction fields with isotropic consistency information to position the target areas of the images corresponding to the transmission lines; and positioning the centers of the spacers by a histogram-based and normalized-correlation quick template matching algorithm. The quick template matching algorithm sets histogram matching joint threshold values and normalized-correlation matching maximum values as the foundation for judging the matching optimal positions, coordinates with the maximum probabilities in a plurality of matching results are selected to be used as center points of the spacers, and reference information is provided for monitoring conditions of the transmission lines and predicting faults.

A determination target region includes a combination of a red gray image, a green gray image, and a blue gray image. A CPU part transforms a three gray value matrixes to a single first data array uniquely associated with a pixel position in the determination target region. The CPU part calculates a normalized correlation value with a single second data array transformed from a model image according to the same predetermined rule, and determines whether or not a match is found with the model image according to whether or not the normalized correlation value exceeds a predetermined threshold value.

The invention belongs to the field of image processing and computer vision and particularly to a TLD-based variable-scale target tracking method suitable for UAVs. The method uses a design thought of a tracking-learning-detection (TLD) frame, uses a median optical flow tracker as a tracker, a normalized correlation detector as a detector, and an improved kNN detector as a learning device. Based on the characteristics and difficulties of a UAV detection video sequence, the TLD-based variable-scale target tracking method suitable for UAVs takes account of algorithm performance and adaptability, integrates the advantages of a median optical flow method and a correlation tracking algorithm, and solves the target robust tracking problem of the target tracking of a UAV video processing system when a target is given indefinitely, less pixels of the target to be tracked, unobvious texture, obvious target appearance attitude angle and scale changes, and tracking process real-time performance.

To determine authenticity of a solid body simply and precisely, a reference area of a paper sheet which is genuine is optically read from two different directions, and the image is registered as a reference image. A check area of a paper sheet subjected to the authenticity determination, including the reference area and having a size larger than the reference area, is read from two different directions with a scanner, and data on a partial area having the same size as the reference area are extracted from each set of check data collected by the reading. For a set consisting of the reference image and the check image optically read from the same direction, the value of the correlation with the reference image is repetitively calculated by the normalized correlation method while the partial area is shifted within the check area. The maximum correlation value and the normalized score of the maximum correlation value are compared with respective thresholds to determine the authenticity of the paper sheet. If the paper sheet is determined to be “genuine” for the authenticity determination of each set, the paper sheet subjected to the authenticity determination is finally determined to be “genuine.”

An image defect inspecting apparatus of the present invention includes a template image producing section for producing a template image from reference image data, a corresponding image extracting section for extracting a predetermined image located at a position corresponding to a template image from digital data of a scanned image for inspection, data embedding sections for embedding desired same pattern data into the template image and the image extracted by the corresponding image extracting section, a normalized correlation value calculation processing unit for acquiring a normalized correlation coefficient from the template image and the extracted image, into which the pattern data is embedded, and a defect judging section for judging as to whether a defect is present by comparing the normalized correlation coefficient acquired by the normalized correlation value calculation processing unit with a predetermined threshold value so as to acquire a large/small relationship thereof.