Abstract: Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design of structures include, in one aspect, a method for hybrid surface modelling with subdivision surfaces and NURBS surfaces, the method including: modifying a control mesh (in accordance with received input) of a subdivision surface model including a topological control that tracks mesh to NURBS relationships for a limit surface of the subdivision surface, and stored NURBS surfaces representing the limit surface; obtaining an updated limit surface from the modified control mesh; finding at least one modified NURBS surface in the stored NURBS surfaces in accordance with relationship(s) tracked in the topological control; and for each modified NURBS surface, updating the modified NURBS surface with its corresponding replacement NURBS surface, and applying at least one geometric modification (associated with a modified NURBS surface in a history procedures system) to the associated modified NURBS surface a

Abstract: A method and an associated controller for safely operating a multi-axis kinematic system by using a safety function are disclosed. The method includes calculating compensation values at the run time of a controller of the multi-axis kinematic system, wherein the calculation is performed based on predefinable error values of respective axes, geometric parameters of the multi-axis kinematic system, and current axis values of the multi-axis kinematic system. The method further includes operating the safety function based on the calculated compensation values.

Abstract: Various implementations disclosed herein interpret data that define curves to display the curves in a 2D or 3D environment. In some implementations, vertices are used to represent control points that specify the geometry of a curve. These vertices are changed in an extrusion process that moves and/or adds vertices to ensure that sufficient pixels are available for anti-aliasing during rasterization, while also providing changed vertices that can be interpreted to accurately render the curve's geometry.

Abstract: A method and system for computer aided design (CAD) is disclosed for designing geometric objects, wherein interpolation and/or blending between such objects is performed while deformation data is being input. Thus, a designer obtains immediate feedback to input modifications without separately entering a command(s) for performing such deformations. A novel N-sided surface generation technique is also disclosed herein to efficiently and accurately convert surfaces of high polynomial degree into a collection of lower degree surfaces. E.g., the N-sided surface generation technique disclosed herein subdivides parameter space objects (e.g., polygons) of seven or more sides into a collection of subpolygons, wherein each subpolygon has a reduced number of sides. More particularly, each subpolygon has 3 or 4 sides. The present disclosure is particularly useful for designing the shape of surfaces. Thus, the present disclosure is applicable to various design domains such as the design of, e.g.

Abstract: A computer-implemented method for 3D reconstruction including obtaining 2D images and, for each 2D image, camera parameters which define a perspective projection. The 2D images all represent a same real object. The real object is fixed. The method also includes obtaining, for each 2D image, a smooth map. The smooth map has pixel values, and each pixel value represents a measurement of contour presence. The method also includes determining a 3D modeled object that represents the real object. The determining iteratively optimizes energy. The energy rewards, for each smooth map, projections of silhouette vertices of the 3D modeled object having pixel values representing a high measurement of contour presence. This forms an improved solution for 3D reconstruction.

Abstract: A processor receives a request to communicate a source data using a preferred communication channel and obtains a first set of communication templates that correspond to a type of the source data and the preferred communication channel. The processor obtains a performance indicator associated with each communication template from the first set of communication template and selects from the first set of communication templates, a communication template associated with the highest value of the performance indicator. The processor transforms the source data using the selected communication template by formatting the source data based at least on one or more multimedia components associated with the selected communication template and transmits the transformed source data using the preferred communication channel.

Abstract: A method for operating a thermal imaging camera includes measuring two-dimensional temperature information including a thermal image of a setting using an infrared detector array of the thermal imaging camera, the infrared detector array including a plurality of pixels sensitive to infrared radiation. At least one of ambient humidity information and ambient air temperature information is provided. An evaluation device is used to calculate two-dimensional information about a mold formation risk. The method includes generating a mold risk map of the setting using a mold growth model and using the calculated two-dimensional temperature information, and the provided at least one of ambient humidity information and ambient air temperature information.

Abstract: A handwriting processing method, a handwriting processing device and a non-transitory storage medium. The handwriting processing method includes: acquiring a handwriting point group corresponding to a stroke on a working surface of a touch device, the handwriting point group including a plurality of handwriting points arranged in sequence, and data of each handwriting point in the plurality of handwriting points including a coordinate and an action type, determining a plurality of model patterns corresponding to the plurality of handwriting plurality of model patterns being in one-to-one correspondence with the plurality of handwriting points; and sequentially connecting the plurality of model patterns, to determine a handwriting track for displaying corresponding to the handwriting point group.

Abstract: A display apparatus includes a processing portion. The display apparatus is configured to display physical quantity related to a state of a machine apparatus. The processing portion is configured to display an image in which a plurality of pieces of partial time-series data extracted from time-series data related to the physical quantity are arranged in a state where time information is provided in the image, the time information being related to time in which the plurality of pieces of partial time-series data has been acquired.

Abstract: Vector format based computer graphics tools have become very powerful tools allowing artists, designers etc. to mimic many artistic styles, exploit automated techniques, etc. and across different simulated physical media and digital media. However, hand-drawing and sketching in vector format graphics is unnatural and a user's strokes rendered by software are generally unnatural and appear artificial. In contrast to today's hand-drawing and sketching which requires significant training of and understanding by the user of complex vector graphics methods embodiments of the invention lower the barrier to accessing computer graphics applications for users in respect of making hand-drawing or sketching easier to perform. Accordingly, the inventors have established a direct vector-based hand-drawing/sketching entry format supporting any input methodology.

Abstract: An example system includes a first and second digital device. The first digital device may be configured to provide an interface displaying an image including a depiction of an object, place a bounding shape around the object, and crop contents of the bounding shape to create a portion. The second digital device may be configured to receive the portion, retrieve high-level features and low-level features, apply first Atrous Spatial Pyramid Pooling (ASPP) to the high-level features to aggregate the high-level features as aggregate features, concatenate results to create the aggregate features, up-sample, apply a convolution to the low-level features, concatenate the aggregate features with the low-level features after convolution to form combined features, segment the combined features to generate a polygonal shape outline along outer boundaries of the first object, and provide the first polygonal shape outline to the first digital device for display.

Abstract: A method and apparatus for automatically measuring and storing a various measured values of an item, or a sequence of measured values of one or more item(s) suitable for single-handed use by a user. In particular, the present invention relates to a mobile computing device with one or more sensors for determining when to measure and record a particular value of one or more items. The mobile computing device may automatically measure the values based on sensing a change in the temperature value or through using proximity as detected by one or more onboard sensors. Additionally, the mobile computing device may automatically measure the values based on coming within range of an external proximity device. In response to automatically measuring the values, the measured values are stored along with additional information for record keeping purposes.

Abstract: Systems and methods provide for efficiently and accurately determining a simplified path that conforms to the geometry of an original path by simultaneously minimizing the deviation from the original path and reducing the number of anchor points in the simplified path. A simplified path may be iteratively generated by updating parametric values and anchor points for candidate simplified paths at epochs. A deviation in distance between points on the original path and corresponding points on candidate paths may be iteratively decreased to ensure that the resulting simplified path follows the geometry of the original path to a predetermined threshold. Continuity constrains can also be applied to ensure smoothness of the simplified path.

Abstract: There is described a method of rasterizing a computer model. One or more non-linear expressions of code are identified in a fragment shader. The one or more non-linear expressions of code are transformed into one or more linear expressions of code. The one or more linear expressions of code are transferred from the fragment shader to a vertex shader. The computer model is then rasterized by executing, on the computer model, code comprised in the vertex shader, including the transferred one or more linear expressions of code.

Abstract: One or more stereoscopic images are generated based on a single monoscopic image that may be obtained from a camera sensor. Each stereoscopic image includes a first digital image and a second digital image that, when viewed using any suitable stereoscopic viewing technique, result in a user or software program receiving a three-dimensional effect with respect to the elements included in the stereoscopic images. The monoscopic image may depict a geographic setting of a particular geographic location and the resulting stereoscopic image may provide a three-dimensional (3D) rendering of the geographic setting. Use of the stereoscopic image helps a system obtain more accurate detection and ranging capabilities. The stereoscopic image may be any configuration of the first digital image (monoscopic) and the second digital image (monoscopic) that together may generate a 3D effect as perceived by a viewer or software program.

Abstract: A method for processing a touch signal includes: detecting, through an event dispatch process, a full-screen gesture touch signal, determining whether the full-screen gesture touch signal conforms to a full-screen gesture trajectory determination rule; and sending, based on a result of the determining, the full-screen gesture touch signal or a part of events of the full-screen gesture touch signal to a gesture processing process or an application processing process.

Abstract: A touch input device includes: a position detector that determines an input range in a touch input produced with an inputter on a touch panel and that detects, as a touch position, any position within the input range; a line information generator that generates line information which is information of a line connecting a plurality of the touch positions detected with the position detector; a smoothing level setter that sets, based on the area of the input range, a smoothing level indicating the degree of smoothing; and a smoothing processing processor that executes, on the line of the line information generated by the line information generator, smoothing corresponding to the smoothing level set by the smoothing level setter.

Abstract: A tool path compensation device according to an aspect of the present disclosure includes: a tool path acquisition unit which acquires tool path information that specifies a tool path on which a tool machining a workpiece moves by way of a plurality of command points through which the tool should pass; a tool shape acquisition unit which acquires tool shape information that specifies a shape of the tool; a target shape acquisition unit which acquires target shape information specifying a target shape after machining of the workpiece; and a density adjustment unit which adjusts a density of the command points, so that the density of the command points becomes larger as curvature of the target shape increases.

Abstract: A method is provided for modifying an image. The method comprises displaying an image, the image comprising a portion of an object; and determining if an edge of the object is in a location within the portion. The method further comprises detecting movement, in a member direction, of an operating member with respect to the edge. The method still further comprises moving, if the edge is not in the location, the object in an object direction corresponding to the detected movement; and modifying, if the edge is in the location, the image in response to the detected movement, the modified image comprising the edge in the location.

Abstract: A biometric information display device includes a display controller configured to display a morphological image indicative of a morphology of a subject, on a display, an input controller configured to receive a designation of a specified position on the morphological image, a pathway generating section configured to generate a pathway based on the specified position on the morphological image, and a current extracting section configured to extract current components at a plurality of positions along the pathway, based on current information reconstructed based on magnetic field measurement data generated by the subject. The display controller displays the current components extracted along the pathway on the display.

Abstract: A computer displays data sources associated with tables of data. The computer also displays data object icons, each representing a logical combination of tables. While displaying the data sources and the data object icons, the computer detects a portion of an input on a table. In response, the computer generates a candidate data object icon corresponding to the table. The computer also detects another portion of the input on the candidate data object icon. In response, the computer moves the candidate object icon towards the data object icons, while providing a visual cue connecting the candidate object icon to a neighboring data object icon. The computer detects yet another portion of the input, and, in response, displays a connection between the candidate object icon and the neighboring data object icon, and updates the tree of the one or more data object icons to include the candidate data object icon.

Abstract: In implementations of systems for generating indications of perceptual linear regions of vector objects, a computing device implements a linear region system to receive input data describing an outline of a vector object. The linear region system determines differences between sequential points of the outline and linear approximation lines projected through the sequential points. The linear region system combines a first linear group and a second linear group of the linear groups into a combined group based on a linearity constraint. An indication of a perceptual linear region of the vector object is generated for display in a user interface based on the combined group.

Abstract: In some implementations, a computing device can perform multi-display alignment through observed user interactions. The computing device can receive user input aligning a first alignment object on a first display device with a second alignment object on a second display device. The computing device can align the display buffers for each display device based on the positions of the alignment objects in each display buffer corresponding to each display device. The computing device can align display buffers based on observed movements of graphical objects between multiple display devices. When display buffers corresponding to the display devices are misaligned, the user may correct the path of a graphical object when moving the graphical object between display devices. The computing device can detect the correction and align the display buffers of the display devices so that graphical objects are presented at the appropriate locations when moved between the display devices.

Abstract: A robotic motion control method provided by the present disclosure includes: obtaining a position and orientation of a starting point where the robot is currently located through a positioning sensor, and obtaining a position and orientation of a preset target point where the robot is moved to; determining an arc path and a straight path of the robot according to the position and orientation of the starting point, the position and orientation of the preset target point, and a preset arc radius; and moving the robot to the preset target point according to the determined arc path and straight path. Because there are only pure circular motion and pure linear motion which are simple during the movement of the robot, it is beneficial to improve the precision of the motion control of the robot and enable the robot to reach the target position in a reliable manner.

Abstract: A programmatic arbitrary distribution of items in a modeling system may be provided. To perform the distribution, a surface may be received, and a point count of application points associated with locations on the surface may be determined. A density map may be applied over the surface to assign a density to portions of the surface for the point count. Application points are then assigned to locations on the surface according to the density map and a scattering function of the point count, where the scattering function is based on one or more repulsion forces between neighboring points. The one or more repulsion forces are treated as pushing each of the neighboring point apart. Thereafter, the surface may be provided having the application points scattered across the surface based on the one or more repulsion forces.

Abstract: Graphical interactive model selection is provided. A response variable vector for each value of a group variable and an explanatory variable vector are defined. A wavelet function is fit to the explanatory variable vector paired with the response variable vector defined for each value of the group variable. Each fit wavelet function defines coefficients for each value of the group variable. A curve is presented for each value of the group variable and is defined by the plurality of coefficients of an associated fit wavelet function. An indicator is received of a request to perform functional analysis using the coefficients for each value of the of the group variable based on a predefined factor variable. A model is trained using the coefficients for each value of the group variable and a factor variable value associated with each observation vector of each plurality of observation vectors as a model effect.

Abstract: A method for smoothing coordinates, a touch chip, and an electronic terminal are provided. The method includes: acquiring touch point coordinates of a current data frame on a touch screen, and touch point coordinates of N consecutive data frames prior to the current data frame, the N is a natural number greater than or equal to 2; performing a Bessel interpolation iteration on the touch point coordinates of N+1 data frames including the current data frame with the touch point coordinates of the N+1 data frames as initial iteration values; and acquiring an iteration result of the Bessel interpolation iteration, and implementing coordinate smoothing according to the iteration result. According to the embodiments of the present disclosure, the cost of smoothing coordinates is lowered, and the effect of smoothing coordinates is improved.

Abstract: An image generator generates images of a set of virtual fibers and effects thereon by processing representations of the set of fibers and computing representation of a virtual surface for a fiber clump in the set of virtual fibers from an artist parameter representing a desired artist effect, computing correlations of the vertices from a set of vertices based on associations of the vertices corresponding to the artist parameter, computing a set of relevant vertices using the correlations of the vertices, computing orthogonal gradients to produce a plurality of gradients using a selected vertex and the set of relevant vertices for the fiber clump, and computing the virtual surface of the fiber clump from the plurality of gradients.

Abstract: Artificial intelligence is introduced into an electronic meeting context to perform various tasks before, during, and/or after electronic meetings. The tasks may include a wide variety of tasks, such as agenda creation, participant selection, real-time meeting management, meeting content supplementation, and post-meeting processing. The artificial intelligence may analyze a wide variety of data such as data pertaining to other electronic meetings, data pertaining to organizations and users, and other general information pertaining to any topic. Capability is also provided to create, manage, and enforce meeting rules templates that specify requirements and constraints for various aspects of electronic meetings.

Abstract: An image scaling method based on a linear extension/contraction mode, includes step I: compressing an original image matrix composed of image pixels in a row by row manner with a Linearlization or OptimalPLR compression method to obtain a line segment segmentation form; step II: lengthening the line segments under Policy I or shortening the line segments under Policy II by resampling at a upscaling or downscaling factor, to obtain an upscaled or downscaled image in the row direction; and step III: upscaling the data upscaled in the row direction in the step II in a column by column manner through the process in the step II, to obtain an image upscaled in the column direction. The method which is an image scaling technique directly based on PLA for data compression, not only can compress static image data, but also can compress image data of dynamic data streams.

Abstract: The present invention provides a method that includes accepting a plurality of positional data with corresponding times of the motion, determining one or more continuous positional functions that together represent an approximation of path of the positional data, and determining, for each positional function, one or more time functions that together represent an approximation of the times for the positional data corresponding to the positional functions.

Abstract: Methods and apparatuses for compressing drive curves for scanning devices and corresponding computer programs are provided. In this case, a drive curve is decomposed into segments. Segments which are not yet present in a library are stored in the library. Moreover, for each segment a pointer to a corresponding segment in the library is stored in a list.

Abstract: Techniques are disclosed for tracing a vector image over at least a part of a raster image. One or more edges of the raster image (e.g., bitmap or photograph) are identified, and an edge model is generated. The edge model is a vector image including a plurality of Bezier curves that overlap with the edges of the raster image. One or more user inputs are received, which identify a first and second path point on the edge model. A subset of the plurality of Bezier curves that are between the first and second path points and on the edge model are selected. The subset of the plurality of Bezier curves are displayed, without displaying Bezier curves that are not within the subset. In an example, the subset of the Bezier curves traces edges of a section of the raster image between the first and second path points.

Abstract: The present disclosure relates to systems, methods, and non-transitory computer readable media for removing an anchor point from a Bezier spline while preserving the shape of the Bezier spline. For example, the disclosed systems can replace adjacent input segments of an initial Bezier spline that are connected at an anchor point with a new contiguous segment that does not include an anchor point and that spans the portion of the spline covered by the adjacent segments. The disclosed systems can utilize an objective function to determine tangent vectors that indicate locations of control points for generating the new segment to replace the adjacent segments. In addition, the disclosed systems can generate a modified Bezier spline that includes the new segment in place of the adjacent segments of the initial Bezier spline.

Abstract: Computer-implemented methods and apparatus are provided for annotating digital images of line plots with ground truth labels. For each digital image, such a method includes supplying image data defining the image of a line plot to a machine-learning model trained to generate a set of control points defining a spline corresponding to the line plot. The method further comprises displaying the spline, and the set of control points, superimposed on the image in a graphical user interface and, in response to user manipulation via the graphical user interface of one or more control points, dynamically adjusting the displayed spline in accordance with manipulated control points whereby the displayed spline can be adjusted for conformity with the line plot. The set of control points for the adjusted spline is then stored as a ground truth label for the image.

Abstract: It is an object of the present invention to provide a technique capable of reducing a difference between a three-dimensional shape represented by map data, using approximation, and a real three-dimensional shape. A map data generating apparatus is a map data generating apparatus capable of generating map data representing a three-dimensional shape, using approximation, the map data generating apparatus including: an acquisition part that acquires a shape point sequence indicating the three-dimensional shape, and a control part that generates an arc passing three object points, based on the three object points in the shape point sequence acquired by the acquisition part, and determines whether an approximation division point that should not be approximated in the three-dimensional shape is included in the three object points, based on the arc.

Abstract: An activity recognition method includes steps of obtaining a plurality of embedded feature values, converting a data set obtained by at least one sensor into an activity feature value, comparing the activity feature value with the embedded feature values to generate a comparison result, and performing an activity recognition according to the comparison result. Therefore, the present invention achieves the advantages of precisely recognizing activities.

Abstract: A method for rendering an object is provided. The method may include obtaining tile information associated with a region of interest (ROI) from a database. The method may include extracting, from the tile information, one or more links along a center line of an overpass in the ROI. The method may include determining at least one intersection of the one or more links. The method may include performing a topology analysis on the one or more links and the at least one intersection to generate a link chain of the one or more links. The method may include constructing a model of the overpass based on the link chain of the one or more links. The method may further include rendering the model of the overpass.

Abstract: Implementations of the present disclosure relate to methods, systems, and computer program products for multimedia object management. In one implementation, a computer-implemented method is disclosed and the method may be implemented by one or more processors in a computer. In the method, a graphic pattern indicating a request for searching in a repository for at least one target object may be received. A search condition may be obtained from the received graphic pattern by a graphical analysis. Based on an association model indicating associations between the search condition and at least one feature of one or more objects in the repository, at least one target object may be found according to the obtained search condition. In other implementations, a computer-implemented system and a computer program product for searching for at least one target object is disclosed.

Abstract: In processing to thicken a white thin line, the application range thereof is controlled to as to prevent a white thin line not intended by a user from being thickened. The thickening processing is performed for a line that has a density less than or equal to a predetermined density and includes a pixel having attribute information of a drawing object; and not performed for a line that has a density less than or equal to the predetermined density and includes a pixel not having attribute information of the drawing object.

Abstract: Stroke operation prediction techniques and systems for three-dimensional digital content are described. In one example, stroke operation data is received that describes a stroke operation input via a user interface as part of the three-dimensional digital content. A cycle is generated that defines a closed path within the three-dimensional digital content based on the input stroke operation and at least one other stroke operation in the user interface. A surface is constructed based on the generated cycle. A predicted stroke operation is generated based at least in part on the constructed surface. The predicted stroke operation is then output in real time in the user interface as part of the three-dimensional digital content as the stroke operation data is received.

Abstract: Techniques for intuitive modifications of digital graphics in a digital media environment are described. For example, a digital graphics creation system accesses vector artwork including a vector object, such as a Bezier curve. The digital graphics creation system receives user inputs, including a user input defining handles on the vector object and a user input interacting with the handles indicating a desired change to the vector object. The digital graphics creation system modifies the vector artwork, including the vector object, by accounting for topology of the vector object and maintaining connections between connected segments of the vector object. The digital graphics creation system outputs the modified vector artwork, including the vector object, such as in a user interface.

Abstract: Systems and techniques are described herein for generating a triangle mesh for an image represented by curves (e.g., Bezier segments). An outline of an image is determined and reduced to a set of connected polylines that are efficiently represented in an edge list. A triangle mesh is generated based on the edge list, rather than by directly sampling the curves of the image and using the samples as vertices of triangles. Thus, the triangle mesh is generated with a number of triangles independent from a number of curves representing the image. Samples of the curves are bound to the triangle mesh by representing the samples with barycentric coordinates with respect to a triangle in the mesh. Hence, once a mesh is deformed, locations of the samples are determined from the barycentric coordinates and triangles in the deformed mesh, and used to reconstruct the curves of the deformed image.

Abstract: Photorealistic image stylization concerns transferring style of a reference photo to a content photo with the constraint that the stylized photo should remain photorealistic. Examples of styles include seasons (summer, winter, etc.), weather (sunny, rainy, foggy, etc.), lighting (daytime, nighttime, etc.). A photorealistic image stylization process includes a stylization step and a smoothing step. The stylization step transfers the style of the reference photo to the content photo. A photo style transfer neural network model receives a photorealistic content image and a photorealistic style image and generates an intermediate stylized photorealistic image that includes the content of the content image modified according to the style image. A smoothing function receives the intermediate stylized photorealistic image and pixel similarity data and generates the stylized photorealistic image, ensuring spatially consistent stylizations.

Abstract: Techniques of generating curves in drawing applications involve generating rational interpolating curves in response input points being specified on a display such that the rational interpolating curves have an adjustable sharpness at each of the input points. Along these lines, a user specifies control points of a curve in a drawing application by, e.g., moving these control points on a display. In response, a computer running the drawing application generates a rational interpolating curve that intersects the input points such that the curvature of each curve at its input point is a local maximum and such that the user's sharpness values change the roundness of the curve around corresponding control points.

Abstract: A numerical controller that creates a tool path from a plurality of command points includes: a command point sequence acquisition unit that acquires an existing command point sequence; a command point creating unit that creates at least one additional command point, based on the existing command point sequence; and an interpolation processing unit that interpolates the existing command point sequence and the additional command point to create the tool path. The command point creating unit outputs, as the additional command point, an intersection point Q1 between an arc C1 passing through consecutive three command points, P0, P1 and P2, in the existing command point sequence and a perpendicular bisector of a line segment whose end points are P1 and P2.

Abstract: This invention relates to as animation authoring system and an animation authoring method, to enable beginners to produce a three-dimensional animation easily and to solve input ambiguity problem in the three-dimensional environment. The animation authoring method according to the invention comprises the steps of: (a) receiving a plane route of an object on a predetermined reference plane from a user; (b) creating a motion window formed along the plane route and having a predetermined angle to the reference plane to receive motion information of the object on the motion window from the user; and (c) implementing an animation according to the received motion information.

Abstract: A makeup part generating apparatus includes a drawing receiver that receives a drawing operation of a makeup part image that is to be overlaid on a facial image, an information acquiring unit that acquires, at each time point in a process of the drawing operation, a progress image that is an image drawn by the time point, and a drawing technique used at the time point, and an information processor that records and outputs makeup part information including, in a time-series manner, image information indicating the progress image, and technique information indicating at least one of the drawing technique and a makeup technique that is an application technique of a cosmetic corresponding to the drawing technique.

Abstract: A method of selection of an object in an environment including a plurality of real and/or virtual objects is described. The environment being displayed to a user through a display device includes an assignment of a gesture path to each object of the plurality of objects and the gesture path includes a series of gestures to be performed by the user to select the object.

Abstract: A method and system for writing trajectory synchronization among multiple clients are disclosed. The method includes: receiving (S10) segmented writing trajectory data of a real-time writing trajectory transmitted in segments by each transmitting end; forwarding (S20) each segment of the segmented writing trajectory data to each receiving end in real time respectively, where the segmented writing trajectory data is received asynchronously and restored into a real-time writing trajectory by each receiving end; receiving (S30) complete writing trajectory data of a complete writing input transmitted by each transmitting end; and forwarding (S40) the complete writing trajectory data transmitted by each transmitting end to each receiving end, where the complete writing trajectory data is received synchronously and inserted into an interface for display by each receiving end.