523 results about "Single camera" patented technology

The invention relates to a common-field-of-view-free camera external parameter calibration method and system based on a laser tracker. The method comprises the following steps: firstly, setting a laser tracker and defining a global coordinate system based on calibration of external parameters of a common-field-of-view-free camera of the laser tracker; for each single camera, if no common view exists between the single camera and the tracker, the tracker is transferred to the position with the common view, a temporary calibration plate is arranged, and the pose relation between the temporary calibration plate and the global coordinate system is calculated; when a public view exists, a calibration plate with a target seat is arranged in the public view, a laser tracker is used for measuring coordinates of a target ball, a camera is used for measuring coordinates of a conversion ball, a target ball coordinate system and a conversion ball coordinate system are respectively established and unified, and therefore the pose relation between the camera and the calibration plate and the pose relation between the calibration plate and the global coordinate system are calculated; and finally, obtaining external parameters of the common-field-of-view-free camera by combining all pose relationships. Compared with the prior art, the method has the advantages that the external parameters of the camera can be accurately and efficiently acquired when the camera system without the public view field is processed, the anti-interference capability is strong, the efficiency is high and the like.

Systems and methods for performing barcoding and machine vision with a single camera are disclosed herein. An example system includes an image sensor configured to capture low-resolution image data of a large field of view and high-resolution image data of a small field of view. A first data pipeline is configured to transmit the low-resolution image data to a first module configured to perform image processing on the low-resolution image data. A second data pipeline is configured to transmit the high-resolution image data to a second module configured to perform image processing on the high-resolution image data. Machine readable instructions cause the system to capture image data of the large field of view or the small field of view and the processor transmits either the low-resolution image data via the first data pipeline or the high-resolution image data via the second pipeline.

The invention provides a method for acquiring the position and attitude of a model through a single camera, and belongs to the technical field of wind tunnel measurement. The method comprises the following specific steps: S1, installing a plurality of to-be-tested coding points on a model; s2, the model is adjusted to an initial attitude, so that the incidence angle, the roll angle and the sideslip angle of the model are all zero; s3, acquiring three-dimensional coordinates of a to-be-measured coding point in the wind tunnel coordinate system, shooting an image of the model by using the main camera, and acquiring two-dimensional pixel coordinates of the to-be-measured coding point in the image; s4, calculating a rotation matrix and a translation vector from a two-dimensional pixel coordinate to a three-dimensional coordinate; s5, moving the model, repeating the step S3, and calculating a rotation matrix and a translation vector from a two-dimensional pixel coordinate to a three-dimensional coordinate; s6, on the basis of the data in the step S4 and the step S5, calculating and acquiring pose information of the model and outputting the pose information; and S7, repeating the steps S5 and S6, and obtaining and outputting the pose information of the model in real time. The data obtained by the method provided by the invention is high in precision and more accurate.

The invention is suitable for the field of image processing, and discloses a fast fusion method for point cloud data of multiple 3D cameras, terminal equipment and a storage medium. The multi-3D-camera point cloud data fast fusion method comprises the steps that calibration data of a plurality of 3D cameras are collected, the calibration data comprise an RGB image, a depth image and an internal reference matrix, and a calibration plate needs to appear in the view fields of the 3D cameras at the same time; generating a three-dimensional point cloud coordinate point set according to the calibration data, and calculating a transformation matrix between the reference camera coordinate system and the non-reference camera coordinate system according to the three-dimensional point cloud coordinate point set; and according to the transformation matrix, registering the three-dimensional point cloud coordinate point set to a preset reference camera coordinate system to obtain merged target point cloud data, the target point cloud data including RGB color values. According to the invention, multi-view complementation is realized, a physical blind area of a single camera can be covered, and the problem of point cloud missing caused by insufficient view field and shielding is solved.

The invention provides a time-space correlation multi-camera personnel tracking method and system, and the method comprises the steps: obtaining video streams of all cameras in a scene, carrying out the frame-by-frame detection of the video streams through a detection module based on a deep learning model, and obtaining pedestrian detection samples under different cameras at the current moment and corresponding appearance features. Associating the detection sample with a historical tracking trajectory to obtain a trajectory in each single camera; and carrying out inter-camera association on the trajectory in the single camera by combining a pedestrian re-identification ReID technology and homography-based spatial constraint to obtain a complete tracking trajectory of the current frame. According to the method, in the aspect of position representation of the trajectory, 2D Kalman prediction is used in an image plane, meanwhile, the 3D space position of the trajectory is predicted and tracked, and the trajectory position can be accurately drawn and output.

The invention discloses an automatic cattle checking method and system based on two-dimensional panoramic vision, and belongs to the technical field of computer vision and intelligent breeding, and the method comprises the following steps: reasonably arranging a plurality of fixed cameras in a cattle farm area, obtaining the internal reference and distortion coefficient of each camera through employing a camera calibration technology, and obtaining the internal reference and distortion coefficient of each camera; performing real-time distortion correction on the collected video frames; on the basis of side-by-side splicing or homography matrix perspective transformation, all paths of corrected images are fused into a complete two-dimensional panoramic image, and a view blind area of a single camera is eliminated; calling a lightweight target detection model on the panorama, and extracting bounding boxes and confidence coefficients of all cattle at one time; sorting according to the confidence from high to low, performing IOU non-maximum suppression de-duplication on the detection frame, and ensuring that the same cattle only counts once in an overlapping region; and the whole process is completed through the edge computing node. According to the invention, efficient, real-time and accurate on-site cattle checking of a large-scale cattle farm can be realized.

A method and system for eliminating 2D features from planar surfaces in 2D images. Three digital images are taken, from a single camera at a fixed position, of a subject such as a pallet of boxes. One image (IA) is taken with ambient lighting, one image (I1) has ambient lighting plus a first added light source, and one image (I2) has ambient lighting plus a second added light source. An output image Q is then computed by Q=(I1−IA) / (I2−IA). Subtracting the ambient image removes ambient diffuse and specular reflections. Division eliminates all variations in the output image caused by color. The only variations that remain are those due to the angle between each surface point's normal direction and the direction from the light to that point. The output image Q, devoid of all colors and 2D features, is well suited for computing a robot grasp of an object in the image.

The invention provides a general dynamic texture generation method and system, and the method comprises the steps: separating a spatial-temporal feature from input data, constructing a spatial feature and a time feature of a texture, and carrying out the fusion of the spatial feature and the time feature, and obtaining a fusion feature; dynamically selecting a physical simulation or statistical modeling path according to a fusion feature type obtained by fusion, and generating a controllable texture evolution rule; and in combination with the generative adversarial network and the neural radiation field, processing the texture evolution rule to generate a visual consistent and physically credible dynamic texture sequence, and outputting a dynamic texture adaptive to the target scene. The method supports the generation of various dynamic textures, is high in coupling, effectively reduces the time cost of repeated modeling, solves the pain points of'fidelity-efficiency paradox 'and'physical-art balance problem' in the existing dynamic texture generation field, and has the advantages of short single-lens manufacturing period, high physical rationality standard-reaching rate and cross-scene multiplexing.

The invention provides a physical driving measurement method for monocular three-dimensional dynamic displacement of a rotary machine, and belongs to the technical field of crossing of computer vision and industrial state monitoring. According to the method, a high-speed dynamic visual acquisition system is constructed, and a time sequence video stream is obtained by using a cooperative marker; constructing a'Gaussian + motion blur 'composite gradient model taking the motion blur width as an endogenous variable, and jointly resolving sub-pixel edge coordinates and ambiguity by adopting a nonlinear optimization algorithm; decoupling the pixel displacement of the radial X axis, the radial Y axis and the axial Z axis by using the width change and the edge displacement of the marker in combination with the geometric principles of sequential robust filtering and monocular imaging; and finally, outputting a three-way physical vibration waveform by using the calibration conversion factor. According to the method, the fuzzy influence is adaptively eliminated from a physical imaging mechanism, micron-level precision three-direction vibration synchronous measurement is realized only by a single camera, and the hardware cost and the deployment difficulty are reduced.

Photometric stereo techniques enable using a single camera to perform an enrollment process for creating a user-specific anatomical model of an eye for gaze tracking. The user-specific anatomical model includes information about a user's center of vision at multiple dilation states of the eye, which can be used to enhance the accuracy of gaze tracking techniques. Accurate gaze tracking techniques enable the use of gaze tracking at close range, for example, gaze tracking within a head-mounted display device.

The invention relates to a double-mechanical-arm calibration method and device based on a single camera and a storage medium. The method comprises the steps of obtaining point cloud data of a first calibration plate; a transformation matrix between a base coordinate system of the first mechanical arm and a camera coordinate system of the camera is calculated according to the first calibration plate point cloud data, and a first transformation matrix is obtained; obtaining point cloud data of a second calibration plate; calculating a transformation matrix between a base coordinate system of the second mechanical arm and the camera coordinate system according to the point cloud data of the second calibration plate to obtain a second transformation matrix; calculating a double-arm calibration transformation matrix according to the first transformation matrix and the second transformation matrix; compared with a traditional double-camera hand-eye calibration method and a calibration method based on a measuring instrument, the cost of the technical scheme is lower, and the calibration steps are simpler and more efficient.

The invention discloses a multi-camera acquisition image splicing method, which comprises the following steps: arranging cameras, and determining the breadth information of a single camera; calibrating the camera through the calibration plate, and calculating camera parameters; calculating physical coordinates of the corresponding processing alignment pattern of each camera according to a preset camera interval; performing image processing on a machine processing plane based on the physical coordinates of the centers of the camera alignment patterns, determining the alignment pattern corresponding to each camera, and calculating an alignment change matrix; splicing transformation is carried out on images collected by the camera, splicing transformation images are determined, and a splicing transformation image set is established; carrying out image splicing on the splicing transformation images in the splicing transformation image set based on the line direction to obtain a line direction splicing image; and carrying out image splicing on the row direction spliced image based on the column direction, and determining a final spliced image. According to the processing breadth visual field information input by the user, splicing of the images collected by the multiple cameras is effectively completed, and the image splicing precision is improved.

The invention relates to the technical field of image processing, solves the problems that in the prior art, UV flat plate printing needs multiple cameras to cover the whole printing platform, and the precision is not high, and provides a scanning image processing method and device based on a single camera, equipment and a medium. The method comprises the steps that a camera is controlled to scan a calibration graph in the main scanning direction to obtain a first area image, the first area image is analyzed to correct distortion, target images are obtained, then the camera moves in the auxiliary scanning direction and repeatedly scans to obtain a second area image, distortion correction is conducted as well, and overlapped parts of the two target images are compared to obtain a target image. And longitudinal shooting overlapping parameters are calculated, and adjacent target area images are spliced by using the two groups of longitudinal overlapping parameters through a mapping splicing technology. Scanning of the whole printing platform can be completed through a single camera, hardware configuration is simplified, image splicing is carried out after multiple times of scanning and distortion correction, and the overall printing precision is improved.

A method for adjusting camera intrinsic parameters of a single camera visual tracking device is described. In one aspect, a method includes accessing a temperature of a camera of the visual tracking system, detecting that the temperature of the camera exceeds a threshold, in response identifying one or more feature points that are located in a central region of an initial image, generating a graphical user interface element that instructs a user of the visual tracking system to move the visual tracking system towards a border region of the initial image, and determining intrinsic parameters of the camera based on matching pairs of the one or more detected feature points in the border region and one or more projected feature points in the border region.

The invention provides a calibration method suitable for a single-camera high-precision scanning system. The calibration method comprises the following steps: S1, carrying out area array mode calibration on a linear array camera; by adjusting the exposure time of the line-scan digital camera, moving the base station to image at different positions of the checkerboard, and solving internal parameters and distortion parameters of the line-scan digital camera; s2, line scanning mode calibration; performing line scanning imaging on the checkerboard to obtain pixel coordinates of angular points of the checkerboard; and separating the actual rotation angle of the checkerboard from the projection error, and further deducing the rotation angle of the real camera, thereby completing calibration. According to the calibration requirement of the linear array camera in a scanning imaging scene, a two-stage algorithm combining area array mode modeling and linear scanning imaging correction is provided, and the problem that a traditional calibration method is not applicable under the condition that a single camera is fixed and moves in a single direction is effectively solved.

The invention provides a panoramic image generation method and device, equipment and a storage medium, and the method comprises the steps: carrying out the single-lens calibration of a wide-angle camera according to a checkerboard calibration method, and obtaining a distortion correction matrix; controlling the wide-angle camera and the array camera to perform time-space synchronous acquisition to obtain an initial panoramic image and a sub-image set; performing nonlinear distortion correction on the initial panoramic image according to the distortion correction matrix to generate a distortionless standardized panoramic image; acquiring sub-image feature information of each sub-image in the sub-image set, and acquiring a projection position, a perspective transformation matrix and a scale transformation matrix corresponding to each sub-image in the standardized panoramic image according to the sub-image feature information; and establishing a panoramic canvas coordinate system according to the standardized panoramic image, projecting each sub-image into the panoramic canvas coordinate system according to the corresponding perspective transformation matrix and the projection position, adjusting the size corresponding to the sub-image in the panoramic canvas coordinate system according to the scale transformation matrix, and generating a panoramic image according to the adjusted panoramic canvas coordinate system.

The invention provides an optical lens, a camera module and electronic equipment, the optical lens comprises a first lens group, a second lens group, a light guide module and a rear lens group, when the optical lens is in a first imaging mode, the light guide module is used for reflecting first light from the first lens group to the rear lens group, and the second lens group is used for reflecting second light from the second lens group to the rear lens group; when the optical lens is in a second imaging mode, the light guide module is used for reflecting second light from the second lens group to the rear lens group, and the optical lens has different effective focal lengths in the first imaging mode and the second imaging mode; the rear lens group comprises a third lens group and a fourth lens group which are sequentially arranged in the direction from the object side to the image side, and at least one of the third lens group and the fourth lens group is a focusing lens group capable of moving along the optical axis. The optical zoom function can be realized by using a single camera module, and many defects of a multi-module relay type optical zoom scheme in the prior art can be solved.

The invention discloses a 3D human avatar method and a 3D human avatar system which are generated based on 3d gaussian patterning and can be driven in real time. The 3D human avatar system comprises a data acquisition module, a Gaussian initialization module and a training rendering module, the data acquisition module acquires a small amount of human body data based on a single camera, predicts human body posture information based on an smplx model and expression information based on a Flame model from two-dimensional human body image data, and makes labels; a Gaussian initialization module carries out adaptive Gaussian initialization on a human body smplx model grid in any frame label to obtain a 3D Gaussian ellipsoid; and the training rendering module is used for training the 3D Gaussian ellipsoid initialized in the step 2 based on an improved 3d Gaussian sputtering model, and rendering a 3D human avatar capable of being driven in real time. According to the method, the topological consistency of the Gaussian point and the human body smplx model can be highly maintained, artifacts are reduced, and high fidelity is improved.

The invention discloses a compact stripe monocular three-dimensional measurement system and method based on a mechanical grating, and belongs to the technical field of measurement sensing. The invention aims to solve the problems that the existing three-dimensional measurement technology depends on expensive active devices, the structure is complex, and single-frame high-density fringe projection and dynamic measurement are difficult to realize. The system comprises a dense fringe projection device, a monocular acquisition module and a processing unit. The compact stripe projection device is composed of an active light source, a mechanical grating and an optical lens, and is used for projecting a single-frame compact stripe formed by the mechanical grating to the surface of an object to be measured. And the monocular acquisition module is used for acquiring a deformed stripe image which is subjected to height modulation by the surface of an object. And the processing unit is used for synchronously controlling projection and acquisition and resolving the acquired single-frame deformed stripe image based on a pre-established system calibration model so as to reconstruct a three-dimensional point cloud coordinate of the object. The passive mechanical grating is adopted to replace traditional digital projection elements such as DLP, MEMS and DOE, and monocular vision and a single-frame reconstruction algorithm are combined, so that the system has the advantages of low cost, small size, single camera and the like, and has wide application prospects in the fields of miniaturized 3D imaging modules, extremely small endoscopes, portable 3D imaging equipment, dynamic 3D imaging and the like.

The invention relates to the technical field of image shielding processing, in particular to a target graph shielding processing method and system based on variable-focus wide-view-angle cameras, and the method comprises the steps: deploying a plurality of variable-focus cameras based on seat distribution, constructing a monitoring network, and collecting an initial image; identifying desktop features according to the images, establishing a unified coordinate system and mapping each desktop; when shooting is needed, querying candidate cameras according to the coordinate system, and determining a main camera according to an imaging area and a distance score; and performing quality evaluation on the main shot image, outputting the main shot image if the main shot image reaches the standard, otherwise, triggering a dynamic re-shooting mechanism. According to the invention, through cooperation of multiple cameras and intelligent visual angle selection, the problem that a single camera is easy to block is effectively solved, and automatic and high-quality image acquisition and processing are realized.

The present invention discloses a single-camera multi-projection dual-axis projection structured light three-dimensional reconstruction measurement system, which relates to the technical field of structured light measurement. The method comprises: using a structured light projector to project structured light to a detection object to generate a dual-axis phase-coded fringe image and collect it, reconstructing a height map of the detection object according to the image, eliminating the noise of the occluded area according to the installation position of the structured light projector group and the collected image and obtaining a height map of the unobstructed real height area, fusing the height map of the real height area to obtain a complete and accurate height map, obtaining point cloud data of the detection object according to the height map and performing three-dimensional reconstruction; the present invention can project a 45-degree rotated structured light through a structured light projector and present dual-axis phase-coded fringe on the detection object, eliminate the influence of shadows and high reflections, increase the number of effective point clouds, improve the measurement precision and accuracy of the system, and obtain a complete and accurate measurement result of the detection object.

Disclosed are embodiments for determining the position and speed of a projectile in three-dimensional world coordinates using a single camera and radar. In some embodiments, a method comprises: determining a zero radial speed time of the projectile based on radar measurements of the projectile; determining a radial speed of the projectile at a particular time based on the radar measurements; determining a radial speed slope at the particular time based on the radial speed measurements; determining a two-dimensional image point of the projectile at the particular time; determining a depth scale coefficient at the particular time based on the zero radial speed time, the radial speed, the radial speed slope, the image point, and a homographic transformation; and determining a position of the projectile in space at the particular time based on a three-dimensional position of the camera, the depth scale coefficient, the image point and the homographic transformation.

The invention relates to the technical field of industrial visual inspection, and discloses an asynchronous exposure double-view-field imaging system and method, and the system can achieve the merging of independent view field images collected by two parallel lenses into a single linear array camera through a reflector and a non-polarization beam splitting cube based on the asynchronous exposure double-view-field imaging system. Meanwhile, in cooperation with precise time sequence control, the system drives two independent stroboscopic light sources to be synchronous with line trigger signals of the camera, different view fields are alternately illuminated in odd-even line periods, the camera is made to perform asynchronous exposure, and two paths of image information are collected in a time-sharing mode; and finally, reconstructing two complete, independent and seamlessly spliced detection images from the interleaved data streams through an odd-even line separation algorithm. According to the invention, with the hardware cost of a single camera, the detection visual field is obviously expanded, the detection efficiency and the image geometric precision under the high-line scanning frequency are ensured, and the excellent balance of the performance, the cost and the efficiency is realized.

The present invention relates to the field of distance measurement technology, and discloses a method, device, computer equipment and storage medium for distance measurement of long-distance targets, including: using an image acquisition device to collect image data of a target object, using inertial navigation data synchronized with the image data by a carrier inertial navigation; preprocessing the image data to obtain preprocessed image data; determining the spatial position and direction of each frame of the image; performing feature matching on each frame of the image to obtain the same feature points of each frame of the image; and calculating the distance of the target object based on the same feature points of each frame of the image and the inertial navigation data. The present invention achieves high-precision target distance estimation and motion trajectory inference by combining a monocular camera and an inertial navigation system, thereby solving the limitations of a monocular camera in depth measurement, and can effectively improve the distance measurement accuracy of a single camera for a target, especially a long-distance target. It can be combined with the movement of the carrier in a dynamic scene to provide a more accurate target distance calculation.

The invention relates to the technical field of deformation monitoring, and discloses a large-range deformation measurement method and device based on multi-camera space-time consistency under the complex working condition of AI + vision + IMU fusion. The method comprises the steps of multi-camera data synchronization, IMU data fusion, AI algorithm optimization, space-time consistency calculation and deformation compensation. The method comprises the following steps: enabling multiple cameras to jointly work through a space-time synchronization technology to obtain a multi-view image, recording motion information by using an IMU (Inertial Measurement Unit) to compensate visual errors, fusing and optimizing data by using an AI deep learning model, constructing a measurement model through space-time consistency analysis, and carrying out deformation compensation by combining visual and IMU information. The method avoids the measurement limitation of a single camera, effectively eliminates the measurement error of a complex environment, can achieve high-precision real-time dynamic deformation monitoring in a large range, can be widely applied to the fields of civil engineering, aerospace and the like, and has remarkable innovativeness and application value.

A learning data generation device for generating learning data for learning a recognizer capable of estimating a contour of a sphere making spinning motion, with high accuracy, the sphere being recorded in a single camera video image, is provided. The learning data generation device includes: a spinning rate estimation unit that receives an input of a learning video image in which motion of a spinning sphere is recorded and an initial value of a size of a contour of the recorded sphere in the video image, sets a plurality of set values of the size of the contour based on the initial value, and obtains an estimated value of a spinning rate of the sphere based on the learning video image, for each of the set values; a contour determination unit that receives an input of a true value of the spinning rate of the sphere, the true value being obtained in advance for the learning video image, and determines at least any of a plurality of the set values respectively corresponding to a plurality of the estimated values selected in order of closeness to the true value, as a determined value of the contour; and a learning data output unit that outputs the learning video image and the determined value as learning data.

The invention discloses a vehicle positioning method and device, electronic equipment and a computer program product, and the method comprises the steps: obtaining sensor data and high-precision map data of a vehicle, the sensor data comprising image data of a plurality of cameras and IMU data; performing semantic segmentation on the image data to obtain road sign segmentation results of the plurality of cameras; performing road mark matching according to the road mark segmentation result and the high-precision map data to obtain road mark matching results of the plurality of cameras; constructing a first vehicle pose optimization constraint according to the road sign matching results of the plurality of cameras and the IMU data; and solving the pose of the vehicle at the current moment according to the first vehicle pose optimization constraint and the optimization solution algorithm. According to the method, the vehicle pose optimization constraint is constructed by using the road identification information observed by the plurality of vehicle-mounted cameras, the problem of positioning failure caused by failure of a single camera is avoided, the problem of positioning continuity of scenes such as road identification information loss is solved by using the IMU data, and the positioning precision and stability are improved.

The invention relates to the technical field of photovoltaic cells, and discloses photovoltaic cell glue path printing detection equipment and a photovoltaic cell glue path printing detection method. In the invention, the lighting assembly comprises the first light source and the second light source of different types of light sources, so that the advantages of the different types of light sources can be combined for photographing and imaging in the imaging process, thereby improving the glue path imaging quality; the situation of glue path detection misjudgment caused by too small glue path gray scale difference value due to imaging shadow of a single-type light source is prevented; meanwhile, the optical imaging assembly is additionally provided with four cameras from a single camera, one camera corresponds to one quadrant of the battery piece, and each camera can capture more details of the battery piece in the imaging process, so that the imaging precision and effect are improved, the glue path analysis and detection precision is further improved, the misjudgment rate of battery piece printing defects is reduced, and the product quality is improved. The labor cost is saved, and the loss of cell picking during cell detection is reduced.

The invention relates to a three-dimensional projection deformation measurement and error compensation method based on a single camera, and the method comprises the steps: collecting a plurality of projection images at multiple moments through a single camera, and recording an image intensity value at each pixel coordinate in each projection image at each moment; inputting the image intensity value into a pre-trained deep learning model, and outputting three-dimensional height prediction of a corresponding pixel coordinate at a corresponding moment; performing correlation search based on the image intensity values of the pixel coordinates in each projection image at the reference moment and the deformation moment to obtain an optimal pixel displacement component; based on the three-dimensional height prediction of each pixel coordinate at the reference moment and the deformation moment, constructing an image surface displacement vector at the deformation moment by using the optimal pixel displacement component, calculating a three-dimensional displacement field at the deformation moment based on the image surface displacement vector at the deformation moment, and then performing three-dimensional strain field calculation; and finally, an efficient and robust closed-loop process is formed through error compensation, and measurement and compensation of three-dimensional deformation in a single-camera scene are realized.

Systems and methods are provided herein for creating interactive 3D content for XR devices using a single camera. This may be accomplished by receiving a first piece of content comprising a plurality of segments, wherein the first piece of content is recorded by a first camera. A system may identify a first object within a first segment of the first piece of content and compare the first object with a plurality of 3D models stored in a database. In response to determining that a first 3D model of the plurality of 3D models corresponds to the first object, the system then generates a second piece of content, by combining the first 3D model with the first piece of content. The system also generates an index associated with the second piece of content.