550 results about "Fisheye lens" patented technology

To provide a technique to constitute a fisheye lens unit with a small number of lenses. A fisheye lens unit uses a predetermined projection method, wherein a variation for the predetermined projection method is not less than the variation for an equidistant projection method, the variation being expressed by an increment of an image height in relation to an increment of an incident angle at a predetermined incident angle. The fisheye lens unit includes: a first lens group provided on an object side; a second lens group provided on an image side; and an aperture stop provided between the first lens group and the second lens group. The first lens group consists of three or four lenses, the second lens group consists of two or three lenses including a final lens provided on the furthest image side of the second lens group, and the final lens is an aspheric lens that has an aspheric shape on at least one of two surfaces of the aspheric lens.

The present invention is a method for exploring the viewpoint and focal length of a fisheye lens camera (FELC). It employs the characteristic of the central symmetry of the distortion of the fisheye lens (FEL) to set its optic axis by means of a calibration target with a plurality of symmetrically homocentric figures. Once the optic axis is fixed, further disclose the viewpoint (VP) of the FELC along the optic axis through a trail-and-error procedure and calculate its effective focal length and classify it to the primitive projection mode. Because the invention is capable of finding out both the internal and external parameters of the FELC and the calibration method is easy, low-cost, suitable to any projection model, and has greater sensitivity corresponding to an increasing in image distortion, the distortive images can be transformed easily to normal ones which fit in with a central perspective mechanism. Furthermore, the invention is also practicable and excellent in its applications in the fields of quality identification of the FEL and wide-view 3-D metering.

A device for inspecting the inside of an underground pipe line which makes it possible to search for cavities on the outside of the underground pipe over the entire internal peripheral surface of the underground pipe, that is, not only upward of the underground pipe, but also toward both sides and downward thereof, to obtain detailed images of the inner peripheral surface of the pipe line without using a complex mechanism, and to display patterns of cracks and irregularities on the inner peripheral surface of the underground pipe by three-dimensional convergence images. The device comprises a pipe line internal self-propelled vehicle and an on-ground control unit, and the pipe line internal self-propelled vehicle is provided with a radar antenna, a camera equipped with a fisheye lens, a gyro, a laser sensor, and an infrared encoder.

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.

The invention discloses a calibration method of a fish-eye lens imaging system applied to target detection, which comprises the step of mathematical modeling of the fish-eye lens imaging system based on an equidistant projection and the precise calibrations of the intrinsic parameters of the imaging system (including the central point O3(u,v) of an imaging surface), the distance L between the top section of the fish-eye lens and a theoretic refractive optical center plane, the radial distortion coefficient K of the fish-eye lens, an image element aspect scale factor i, the plane torsional angle gamma between a camera coordinate system and an imaging surface coordinate system, various parameter calibration methods and matched software. The method aims at the omnidirectional vision system based on the fish-eye lens, analyzes the optical structure and the imaging principle of the fish-eye lens and introduces deformation parameters so as to establish the physical model of the fish-eye lens imaging system and then deduce the mathematical model of the system. With an independently-developed calibration procedure, three-dimensional space information is obtained from a two-dimensional image and applied to the calibration of imaging system parameters. The method is applicable to the calibration of various fish-eye type panoramic lenses, is convenient and accurate and has strong practicability.

The invention relates to the technical field of image communication, and particularly relates to a method for acquiring a panorama image by using two fish-eye camera lenses. The method comprises the following operation steps: (1) camera configuration: two fish-eye lenses with view angles of greater than 180 degrees are oppositely arranged on a camera, so that two ends of the view angles of the two fish-eye lenses are overlapped; (2) image acquisition: the camera is arranged in a panorama, and acquires a part of the panorama through one fish-eye lens to form a first image, and acquires the other part of the panorama through the other fish-eye lens to form a second image, and two ends of the first image and the second image are overlapped; (3) image processing: a processor of the camera splices the first image and the second image to form a 360-degree panorama image. According to the method provided by the invention, two images can be quickly obtained by the two fish-eye lenses, and combined into a panorama image, the operation is simple and convenient, and the combination effect is good.

A method for generating a presentation of a region-of-interest in an original image for display on a display screen, comprising: establishing a focal region for the region-of-interest at least partially surrounded by a shoulder region; creating a focal region image for the focal region by scaling the original image within the focal region by a focal region magnification; creating a shoulder region image for the shoulder region by scaling the original image within the shoulder region by a shoulder region magnification, the shoulder region magnification being less than the focal region magnification; and, overlaying the focal region image and the shoulder region image on the original image to thereby generate the presentation.

The invention provides an unfolding method for restoration of a fisheye image, and relates to the restoration and correction of a fisheye image based on the equidistant projection principle of a spherical model. The method comprises the following steps of: establishing a spherical imaging model, consistent with the equidistant projection principle, of the fisheye image(including the establishment of a fisheye image coordinate system and a camera coordinate system); establishing an unfolded window coordinate system and an unfolded image coordinate system, and calculating the relationship between the two coordinate systems; establishing the relationship between the unfolded image coordinate system and the camera coordinate system; calculating the relationship between the unfolded image coordinate system and the fisheye image coordinate system; and finally obtaining a whole image unfolded in any specified direction. The method can overcome the defect of the methods that can unfold only the top part information of fisheye lenses and can not only restore the top part information, but also restore all information in any direction, The method can be applied to the equidistant projection principle based fisheye lenses as well as other projection principle based fisheye lenses, so that the method has a wide application prospect in fields of image tracking, monitoring, video conference and the like.

The invention discloses a reflective panoramic imaging system and method. The reflective panoramic imaging method comprises the following steps: directly mounting an optical system on an image sensor or an existing camera optical system, and respectively locating image planes of two groups of fisheye lenses on the image sensor through a reflection element in a non-overlapped manner; selecting a camera to enter a shooting mode; dividing images formed by light on the image sensor after passing by the first fisheye lens and the second fisheye lens; respectively processing the divided images, comprising image correction, color adjustment, noise elimination, exposure and contrast adjustment; extracting, screening and matching feature points of the images; carrying out image registration, splicing and fusion; selecting the shooting mode, and compressing and storing a panoramic image and a panoramic video; and selecting a preview mode, rendering the spliced panoramic image, and displaying the panoramic image on a device connected to the camera. The reflective panoramic imaging method disclosed by the invention can be used for shooting a complete panoramic image, guaranteeing the synchronism of video steam and obtaining the panoramic video more easily.

A method of using fisheye image to generate stereoscopic panorama includes shooting out a numbers of fisheye image by fisheye camera according to specified sequence, confirming character point air at overlapped region of adjacent images and setting-up stereoscopic space model as per obtained matching point pair, calculating out position of original image on stereoscopic space and resampling original fisheye image according to calculated out parameter in order to generate out stereoscopic panorama.

The invention belongs to the field of advanced manufacturing technology, relating to a correction method of fisheye image distortion on the basis of cubic projection. The correction method comprises the following steps: 1. using a fisheye lens to obtain an imaging model, and calibrating the fisheye lens according to the imaging model to obtain a calibration parameter; 2. according to the collected fisheye image, determining a viewpoint, taking the viewpoint as the original point of a coordinate system, and building a cubic perspective projection model to obtain the cubic perspective projection of a spatial point; 3. building a mapping relation between the cubic perspective projection of the spatial point and the fisheye image; and 4. using bilinearity interpolation to realize the distortion correction of the fisheye image. The invention utilizes a cubic projection model to correct distorted fisheye images and can effectively overcome the geometric distortion existing in the original fisheye images, and the corrected image conforms to the intuitional feeling of people and has strong sense of reality.

Various embodiments of a system and method of fisheye lens image planar projection are disclosed. In general, an image created by a camera with a fisheye lens is mapped to an output image in such a way as to greatly reduce perceived distortions of people and other subjects in the output image. An advantage of at least one embodiment is that ultra wide angle fisheye lenses can now be used in a wide range of photographic situations.

The invention discloses a method for obtaining the leaf area index and the average leaf inclination of rice canopy by using a hemisphere photographic process. The method comprises the following steps of: collecting a hemisphere image of rice canopy from bottom to top inside the rice canopy by using a digital hemisphere shooting system based on a fisheye lens; after performing gray conversion and binaryzation on the hemisphere image, obtaining the canopy porosity under the zenith angle at a viewing angle of 57 degrees, and calculating the rice canopies LAI and ALIA under the condition of the single zenith angle at the viewing angle of 57 degrees based on the Beer-Lambert law and a poisson model as well as the two characteristics of the blade projection function of the rice canopy; simulating the leaf inclination distribution of the rice canopy by an elliptic function and optimizing the rice canopies LAI and ALIA calculated by using the single-angle method so as to rapidly acquire the rice canopies LAI and ALIA. The rice canopies LAI and ALIA can be obtained in real time without picking up rice blade outdoors for destructive artificial measurement, and basic parameters for monitoring the rice growth in real time and remotely estimating the yield of rice are provided.

To provide a conference system, a monitoring system, an image processing apparatus, an image processing method and A non-transitory computer-readable storage medium that stores a computer-image processing program capable of accurately and effectively recognizing an object based on a fisheye-distorted image photographed at a wide angle.

When an instruction of selecting an arbitrary point Ci(ui, vi) of a 2D-viewable planar regular image generated based on a fisheye-distorted image S photographed by a fisheye lens is received, point Si(xi, yi) on the fisheye-distorted image S is calculated as a coordinate corresponding to Ci(ui, vi), and a pixel information group configuring the planar regular image is newly generated based on a pixel information group configuring the fisheye-distorted image S.

Disclosed is a fisheye lens comprised of the first through the seventh lens elements: wherein a field of view is larger than 180° a calibrated distortion is 10% or less, a relative illumination is 80% or more, all the refractive surfaces of the lens elements are spherical surfaces, the first lens element is a negative meniscus lens element having a convex surface facing an object side, the second lens element is a bi-concave lens element, the third lens element is a positive meniscus lens element having a convex surface facing an image side, a stop is located between the third and the fourth lens elements, the fourth lens element is a bi-convex lens element, the fifth lens element is a bi-concave lens element, the sixth and the seventh lens elements are bi-convex lens elements.

The invention discloses a splicing method for panoramic images of fish-eye lenses. The method comprises: unit images shot by a plurality of fish-eye lenses are mapped to a three-dimensional spherical surface respectively to determine a polynomial fitting model; a matching feature point in an overlapped area of each image in a plurality of to-be-registered unit images is mapped to the three-dimensional spherical surface by the polynomial fitting model, the multiple unit images are calculated on the three-dimensional spherical surface to obtain registered model matrixes of all unit images, and according to the registered model matrixes, the multiple unit images are registered on the three-dimensional spherical surface to form a spherical panoramic image; the spherical panoramic image is unfolded to form a cylindrical panoramic image; the cylindrical panoramic image is processed, and a parameter mapping table of a correspondence position relation between each pixel point in the cylindrical panoramic image and each pixel point in the multiple unit images is established; and the parameter mapping table is invoked and fish-eye images shot by the multiple fish-eye lenses are fused to obtain a panoramic image. According to the invention, a splicing error in a spliced overlapped area of the fish-eye panoramic image can be eliminated.

A device for converting display screen into touch panel screen includes a projection screen; an image projection unit for projecting an image on the projection screen; a light pointer for emitting a light spot signal of a specific wavelength on the projection screen; an image detecting unit, which includes a fisheye lens for receiving the image on the projection screen to generate a fisheye distorted image; and an optical filter for filtering out the optical energy except the light spot signal of the specific wavelength; an image processing unit, coupled to the image detecting unit, for calculating a first position of the light spot on the projection screen according to the fisheye distorted image; and a message transmitting unit, coupled to the image processing unit, for outputting a touch panel signal according to the calculating result of the image processing unit.