Real-time keystone correction method and system for optical fingerprint sensor

Abstract

The invention relates to an optical fingerprint sensor and provides a real-time trapezoidal distortion correction system for the optical fingerprint sensor. The real-time trapezoidal distortion correction system for the optical fingerprint sensor solves the problems that in the prior art, a digital image correction method is large in operation quantity, low in speed and high in space resource consumption and can not finish or implement trapezoidal distortion correction in a low-end embedded system with limited operational capability. The real-time trapezoidal distortion correction system for the optical fingerprint sensor comprises an image sensor, a hardware collection module, a fourth storage module, a first storage module, a second storage module, a third storage module and a processing module, wherein the image sensor is connected with the fourth storage module through the hardware collection module; the fourth storage module is connected with the first storage module, the third storage module and the second storage module respectively; the first storage module, the third storage module and the second storage module are respectively connected with the processing module. A real-time trapezoidal distortion correction method and the real-time trapezoidal distortion correction system are suitable for the optical fingerprint sensor.

Description

Technical field [0001] The invention relates to an optical fingerprint sensor, in particular to a real-time keystone distortion correction method of the optical fingerprint sensor. Background technique [0002] The optical fingerprint sensor mainly uses the principle of light refraction and reflection. The light is emitted from the bottom to the prism and is emitted through the prism. The angle of the reflected light on the uneven lines of the fingerprint on the finger surface and the reflected light will be different. same. The image sensor (CMOS Sensor, hereinafter referred to as CMOS) or CCD optical device will collect the image information of different brightness and darkness, and then the fingerprint collection will be completed. Therefore, the distortion and area of ​​the fingerprint image are important indicators of the fingerprint collection system. [0003] In the optical fingerprint collection system, the finger presses the surface of the prism to collect fingerprints. ...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is aimed at the problem that in the prior art, the digital image correction method has a large amount of computation, a slow speed, and a large consumption of space resources, and cannot complete the correction of trapezoidal distortion in a low-end embedded system with limited computing power. , providing a real-time trapezoidal correction method for optical fingerprint sensors to achieve real-time judgment of sensor deformation, and a low-complexity calculation method to complete the calculation effect of pixel mapping, while achieving fast calculation speed and low space resource consumption.

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