Automated projection-keyboard calibration method of utilizing four manually selected points

Abstract

The invention discloses an automated projection-keyboard calibration method of utilizing four manually selected points, and aims to solve the problem that larger calibration errors of current calibration methods exist. According to the method disclosed by the invention, firstly, a recognition camera is utilized to shoot a picture of an LED calibration board, and an internal parameter matrix of therecognition camera and distortion coefficients of a distortion model are calculated; then the calibration reference points of a projection keyboard are manually selected, and image coordinates of thecalibration reference points are calculated; a relative position relationship of the recognition camera and the projection keyboard is calculated according to a camera imaging model, and world coordinates of the calibration reference points are determined; a transformation equation of the calibration reference points from a camera coordinate system to a world coordinate system is established according to a projection transformation relationship, and a projection transformation matrix is obtained; and then world coordinates of each key are calculated according to a projected-keyboard size andthe world coordinates of the four calibration reference points, and a keyboard table is generated. The method is suitable for use in automated projection-keyboard calibration.

Description

technical field [0001] The invention relates to an automatic calibration method for a projection keyboard. Background technique [0002] Input devices (keyboards, mice) are important tools for human-computer interaction of computer devices or other smart devices. With the miniaturization of computer devices or wearable smart devices, many products in the electronic field will miniaturize or even miniaturize input devices. , but the smaller the input device, the trouble of inconvenient input is caused to people, but it still cannot meet the needs of mobility and portability. At present, some computer devices or wearable smart devices have adopted projection keyboards as input devices. [0003] However, there are still many problems in the calibration of the projection keyboard. At present, manual calibration is basically used for the calibration of the projection keyboard. In the actual calibration process, manual calibration is used, and each key on the projection keyboard n...

AI Technical Summary

Problems solved by technology

[0002] Input devices (keyboards, mice) are important tools for human-computer interaction of computer devices or other smart devices. With the miniaturization of computer devices or wearable smart devices, many products in the electronic field will miniaturize or even miniaturize input devices. , but the smaller the input device, the trouble of inconvenient input is caused to people, but it still cannot meet the needs of mobility and portability. At present, some computer devices or wearable smart devices have adopted projection keyboards as input devices.

[0003] However, there are still many problems in the calibration of the projection keyboard. At present, manual calibration is basically used for the calibration of the projection keyboard. In the actual calibration process, manual calibration is used, and each key on the projection keyboard needs to be manually Calibration, and the calibration by different personnel will definitely make the calibration results different, bringing errors, which will affect the accuracy of the keyboard calibration

For example, each person's finger size is different, which will lead to inconsistencies in the extraction of fingertip coordinates, which will lead to a decrease in the accuracy of the calibration results

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