337 results about "Nearest point" patented technology

In a biological specimen imaging method, a biological specimen which is stored in a storing section of a substrate having plural storing sections and emitting a feeble light is imaged through an objective lens. The biological specimen imaging method includes moving any one of the substrate and the objective lens or both until the desired storing section falls within the field of view of the objective lens, measuring any one of a focal position at a near point and the focal position at a far point of the objective lens or both, determining the focal position of the objective lens focused on an observed target region in the biological specimen stored in the desired storing section based on the measured focal position, and adjusting the focal position of the objective lens to the determined focal position so as to image the biological specimen through the objective lens.

A capsule endoscope is disclosed that includes a capsule and a transparent cover having a central axis and that is located in front of an objective optical system within the capsule. The objective optical system has a depth of field, a field of view, and an image surface that has curvature of field, and is arranged on the central axis of the transparent cover and the capsule. The field of view of the objective optical system includes a spherical surface that is tangent to the transparent cover at a periphery of the field of view, and the near point of the depth of field on the optical axis of the objective optical system is positioned farther from the objective optical system than is the transparent cover. Various conditions are satisfied so as to provide high quality imaging.

The present invention provides new methods and systems for treating myopia progression in myopic patients who also exhibit near point esophoria, esophoria at near, eso fixation disparity, or eso associated phoria by selectively prescribing bifocal contact lenses to such patients. Near point eso fixation disparity may include esophores, low exophores, and orthophores. One method for controlling myopia progression comprises identifying a near point esophoric myopic patient, measuring an amount of fixation disparity, and prescribing a bifocal contact lens add power prescription. The bifocal add power prescription is based on the fixation disparity measurement and a distance prescription for the patient's eye.

The invention provides an indoor and independent drone navigation method based on three-dimensional vision SLAM. The indoor and independent drone navigation method comprises the steps that an RGB-D camera obtains a colored image and depth data of a drone surrounding environment; a drone operation system extracts characteristic points; the drone operation system judges whether enough characteristicpoints exist or not, if the quantity of the characteristic points is larger than 30, it shows that enough characteristic points exist, the drone attitude calculation process is conducted, or, relocating is conducted; a bundling optimizing method is used for global optimization; an incremental map is built. Drone attitude information is given with only one RGB-D camera, a three-dimensional surrounding environment is rebuilt, the complex process that a monocular camera solves depth information is avoided, and the problems of complexity and robustness of a matching algorithm in a binocular camera are solved; an iterative nearest-point method is combined with a reprojection error algorithm, so that drone attitude estimation is more accurate; a drone is located and navigated and independentlyflies indoors and in other unknown environments, and the problem that locating cannot be conducted when no GPS signal exists is solved.

The invention discloses an improved ICP object point cloud splicing method for fusing fast point characteristic histogram. The method comprises the steps of projecting a standard sinusoidal digital grating onto the surface of the object to be measured, photographing stripe images of the surface of the object projected with the standard sinusoidal digital grating from different angles of view by aCCD camera, and obtaining photographing point clouds from multiple angles of view; for two image point clouds that need to be stitched together, building a k-D tree and interpolate to obtain that interpolated point cloud; for the two interpolated point clouds to be spliced, computing the fast point feature histogram, and obtaining the point cloud by random sampling consistent transformation; usingthe improved iterative nearest point method to obtain the first interpolated point cloud which is precisely registered; overlaying point cloud and mesh to realize the mosaic of two different angles of view of the shooting point cloud. The invention has low requirement for the initial position of the splice point cloud, the robustness is remarkably improved, the local optimization is not easy to fall into, the splice accuracy is improved, and the precise splicing of the point cloud under multi-view angles is realized, so that the practical industrial application requirements can be met.

The invention discloses a laser radar 3D point cloud data combined camera self-calibrating method, and relates to the technical fields of photography measurement and 3D reconstruction. 3D scanning iscarried out on a measured object, images of the same scene are collected in different viewpoints, features are extracted from the multiple collected images to obtain characteristic points, characteristic points in an overlapped area of any two images are searched for a corresponding nearest point, and a matching point pair is obtained by combining a random consistency algorithm; the matching pointpair is used to solve a fundamental matrix F so that the fundamental matrix F is not sensitive to Gaussian white noise; an objective function related to internal reference of a camera is establishedaccording to relation between the fundamental matrix and internal reference of the camera, and an optimization algorithm is used to solve the internal reference of the camera; and the internal reference, of the camera, needed by the optimization algorithm is set on the basis of laser radar 3D point cloud data, a pinhole imaging principle, a pixel size of a CCD camera and an image central position.Thus, the internal reference of the camera is calibrated accurately.

This patent provides an eyesight improving device which improves ocular imaging adjustment functions and is easy to use. A user puts the eyes on eyepiece parts 10, and sees a figure displayed on a target 12 by both eyes or one eye by opening or closing blocking device 14. In a state where the user focuses the eye on the figure, the target 12 is moved from a far point to a near point by target movement device 18 and is next moved from the near point to the far point, and this is repeated. In this case, the size of the figure is controlled to be changed in proportion to the distance between the eyepiecepart 10 and the target 12. The user can easily concentrate to focus the eye on the figure during the movement of the target 12. This training activates the ocular imaging adjustment functions of a ciliary muscle, a pupil, vergences and the like resulting with their improvement.

Systems and methods for a point of sale reward system are provided. The system notifies users proximate to a point of sale location of rewards available for redemption specific to that user at that specific point of sale location.

A focal position determining method determines a focal position of an objective lens focused on an observed target region in a specimen. The focal position determining method includes measuring any one of the focal position of the objective lens at a near point and the focal position of the objective lens at a far point or both so as to determine the focal position of the objective lens focused on the observed target region based on the measured focal position.

The invention relates to a bend pipe measuring and allowance locating method facing digital manufacture. The method comprises the following steps that multiple sensors are calibrated globally by meansof a laser tracker and a target, and coordinate systems of the sensors are unified into a global coordinate system; the sensors collect bend-pipe images and carry out edge detection and morphologicalrefinement to obtain a center line of the bend pipe in a strictly synchronous way, and 3D reconstruction of the center line is carried out in a bidirectional polar line matching algorithm; the centerline is dispersed into space point cloud, a control point, straightway end points and an arc center point of an arc segment are calculated, and 3D molding is carried out by taking the center line asa guiding line; and a design model matches a measurement model via a nearest point iteration method, the allowance position is calculated. Thus, self-locating cutting and welding of the bend pipe is realized, and the digital manufacturing process of the bend pipe is accelerated.

An illumination device is provided to solve locally high luminance near point-shaped light sources, while preventing overall decrease in luminance at the light-emitting face of a light guide member. The illumination device includes a light source for generating light, and a light guide member which receives light from the light source at a light input face and emits light from a light emitting face. A continuous optical pattern with prism faces and flat faces is provided on the light input face. Light emitted from the light source is diffused in the plane direction by the optical pattern, so there is no occurrence of locally-high-luminance areas near the LEDs in the light guide member. Moreover, the luminance of the light emitted in a planar manner from the light-emitting face does not decrease.

The invention relates to a method of acquiring simulated autostereoscopic video images of a scene to be viewed. On the basis of stored data containing three-dimensional information, it implements n simulated cameras, with n>=3, each generating an image of a scene on a given optical axis. The optical axes of the simulated cameras converge at a point situated at the same distance D from the simulated cameras. The scene to be viewed has a nearest point Pp and a farthest point Pe, and the inter-camera distance and the distance Dmin between the simulated cameras and the nearest point Pp are selected in such a manner that for focus varying between the nearest point Pp and the farthest point Pe the angle 2alpha between two adjacent simulated cameras varies between a value not greater than 4.5° for the point Pp and a value not less than 0.2° for the point Pe.

The invention relates to an RSS (received signal strength) fingerprint database based secondary fuzzy clustering indoor-positioning method which includes the following steps of firstly, setting a position of an indoor signal coordinate node and forming an indoor positioning system; secondly, selecting a position of a reference point, measuring an RSS vector accepted by the reference point, and setting up an RSS fingerprint database; thirdly, clustering primarily to obtain a point same with a point to be positioned; fourthly, obtaining a reference point half similar to the point to be positioned, and obtaining an overall nearest point; fifthly, clustering secondarily to obtain a point same with the overall nearest point; and sixthly, weighting all points according to similarity, and computing coordinates of the point to be positioned. The RSS fingerprint database based secondary fuzzy clustering indoor-positioning method has the advantages that impact on positioning accuracy from multiple paths and non-line-of-sight and the like can be avoided effectively, no extra facility support is required and positioning algorithm complexity and cost of a positioning system are reduced.

The invention discloses a control method for a periodic variable-thickness strip rolling speed, and belongs to the technical field of rolling. The control method comprises horizontal rolling speed control and the vertical rolling speed control of a roller, wherein the horizontal rolling speed control is performed in a way that: a thick region of a strip is rolled at a thick region rolling speed; the rolling speed starts to decrease at a near point A of a transition region and decreases to VB at a starting point B of the transition region; at the transition region, the horizontal rolling speed at the transition region is calculated according to a transition region curvilinear equation and a second flow equivalence principle; and the rolling speed starts to increase after an end point C of the transition region and increases to a thin region rolling speed at a far point D of the transition point to start to roll a thin region; the vertical rolling speed control of the roller is performed in the way that: the vertical rolling speed of the roller is 0 when the thick region of the strip is rolled; after the thick region is rolled and a rolled piece reaches the starting point B of the transition region, the roller starts downward pressing, and the vertical rolling speed of the transition region is Vdy(x); the Vdy(x) starts to decrease after reaching a maximum point Q1 and decreases to 0 at the end point C of the transition region; and the steps are repeated periodically.

A capsule endoscope is disclosed having an illumination means, an imaging system that includes an objective optical system, and a transparent cover. The invention is characterized by one of: (1) the transparent cover has a larger radius of curvature in a central region of the field of view of the objective optical system than the radius of curvature of the transparent cover in a peripheral region of the field of view of the objective optical system, or (2) the imaging system has a different near point of focus distance for a central region of the field of view than the near point of focus distance of a region that is peripheral to the central region of the field of view and the objective optical system includes a meniscus lens element of positive refractive power and a plano-convex lens element.

A method fits primitive shapes to a set of three-dimensional (3D) points by first converting the set of 3D points to a distance field. Each element in the distance field is associated with a distance to a nearest point in the set of 3D points. A set of two or more candidates are hypothesizing from the primitive shapes, and a score is determined for each candidate using the distance field. Then, the primitive shape to fit to the 3D points is selected from the candidates according to their scores.

The invention discloses a multimodal multi-dimensional blood vessel fusion method and a multimodal multi-dimensional blood vessel fusion system, and relates to medical equipment data image processing. The method comprises the steps of respectively extracting blood vessel images in a plurality of medical images, and extracting blood vessel center lines corresponding to the blood vessel images; registering and fusing the blood vessel center lines through an iterated near point algorithm, so as to obtain three-dimensional data; and synchronously displaying the three-dimensional data in the way of the cross-sectional image of cross sections, coronal planes and vertical planes. According to the method, other information outside the blood vessels can be rejected, so that no other covers can be generated when a doctor observes the blood vessels.

The present invention relates to a method for generating a mesh model representing a 3D surface from unorganized 3D points extracted from a 3D scanner by using a shrink-wrapping scheme of boundary cells. A method for generating 3-dimensional mesh according to the present invention comprises the steps of: (a) receiving unorganized 3D point coordinates extracted by a 3D scanner or a digitizer; (b) extracting a minimum bounding box including all the point coordinates and uniformly dividing the extracted bounding box into cells of a predetermined size; (c) extracting a boundary cell including at least one point from the cells, extracting a boundary surface from all the boundary cells, and generating an initial mesh by summing extracted boundary surfaces; (d) calculating distances between each vertex constituting the mesh and the several points, finding a nearest point, and moving the vertex to the nearest point; and (e) averaging location of each shrink-wrapped vertex and location of the neighboring vertexes, and moving the shrink-wrapped vertex to center of neighboring vertexes.

The invention provides a point cloud automatic registration method based on a local feature descriptor. an initial matching point pair can be obtained based on a local fast point feature histogram descriptor and a sampling consistency algorithm; A coarse registration matrix is obtained through an error measurement loss function, and then a fine registration rigid body transformation matrix is obtained by combining an iteration nearest point algorithm, so that the problem that three-dimensional point clouds cannot be automatically registered under different visual angles can be effectively solved; Compared with an existing method, the method has the advantages that mark points do not need to be pasted, the method is not affected by a positioning device, an additional auxiliary device is notneeded, the requirement for the environment is not high, efficiency is high, and the method has high robustness in actual measurement.

A low-head impulse jet waterwheel for power generation at irrigation canal drop structures and navigation dam spillways achieves renewable electric power generation that has been lost until now due to lack of suitable equipment to convert such energy at competitive cost. Conventional practice has limited use of impulse turbines to heads of more than 50 meters or about 150 feet. However, there is now no need for such a limitation. Kinetic energy of a low-pressure jet is employed in a way that enables numerous locations to generate electricity conveniently near points of use, from a renewable source at minimum cost. The equipment can be pre-assembled for minimum installation cost at sites with no existing impoundment and can be automatically raised clear of flood levels with built-in lifting equipment. Existing multi-span bridges offer convenient access for installation and maintenance. Raising the equipment also provides clear passage for fish migration.