Planarization pre-processing method

Abstract

The invention provides a planarization pre-processing method comprising the following steps: calculating the covariance matrix of a sampling point; calculating the characteristic value and characteristic vector of the covariance matrix; determining the direction of z' axis according to obtained minimum characteristic value; determining the directions of x' axis and y' axis according to the directions of z axis and z' axis; calculating a coordinate transformation matrix; carrying out matrix transformation on the sampling point; and removing the direction information of z' axis to finish projection. The projection algorithm can determine a projection plane only through the respective statistical characteristic of the sampling point of a handwritten character track so that the determined projection plane changes in adaptability along with the change of an writing angle so as to generate optimal projection effect. Therefore, a writer can perform spatial handwriting with more free postureswithout influencing identification effect.

Description

technical field [0001] The invention relates to handwriting recognition technology, in particular to a preprocessing method in the space handwriting recognition technology. Background technique [0002] Handwriting recognition technology has been developed for many years and can be roughly divided into offline recognition and online recognition. The research object of offline handwriting recognition is a character image, which is a static two-dimensional lattice, while the research object of online handwriting recognition is the coordinates of handwriting points input in chronological order, which not only has spatial information, but also time information. Because online identification has more information, online identification is preferred in the case of instant input. Online handwriting recognition technology can be divided into plane handwriting recognition and spatial handwriting recognition according to different writing spaces. Among them, plane handwriting recognit...

AI Technical Summary

Problems solved by technology

Although plane handwriting recognition is in line with people's traditional handwriting habits, it also has inherent defects: first, there is inevitable direct contact between the stylus and the tablet, which causes equipment wear; second, the input device requires both the stylus A handwriting board is also required, which increases the cost of the equipment, and also makes the handwriting equipment bulky and difficult to carry; third, the writer needs to write on a fixed writing surface, which restricts the writing posture and is prone to fatigue

If a camera is used to capture the handwriting trajectory or designate a writing plane for spatial handwriting, the freedom of writing is still greatly restricted. If it is required to face a specific direction and write on a specific plane, it will not only be prone to fatigue, but also affect the telling effect

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