Algorithm of stripe recognition and information detection for visible light imaging positioning

Abstract

The invention provides a stripe identification and information detecting algorithm used for visible light imaging positioning. The algorithm is applied to an LED transmitter in which FSOOK modulation is utilized. Furthermore an LED lamp is provided with a visible light communication system which is composed of a lampshade and a receiver based on a CMOS image sensor. A layer of antireflecting material is placed in front of the CMOS sensor of the receiver for generating a clear bright-and-dark fringe picture. An effective fringe area is obtained from the obtained bright-and-dark fringe picture. The obtained fringe area is converted to a gray-scale image. Autocorrelation and differential processing are successively performed on the gray-scale image for obtaining an estimated line value of the gray-scale image. The estimated line value is utilized for calculating an estimated FSOOK signal frequency. The stripe identification and information detecting algorithm has advantages of improving resolution of the bright-and-dark fringe generated by the visible light signal through FSOOK modulation, preventing a high-brightness interference problem in the bright-and-dark fringe picture, realizing relatively high information detecting performance, prolonging distance in correctly demodulating the visible light signal, and furthermore supporting wider frequency modulation range.

Description

technical field [0001] The present invention relates to the technical field of visible light positioning, and more specifically, to a stripe recognition and information detection algorithm for visible light imaging positioning. Background technique [0002] Using a mobile phone with a CMOS image sensor (CIS) to receive LED light signals can form bright and dark stripe pictures and realize low-rate information transmission. The flickering LED light signal will form a bright and dark fringe picture on the imaging plane, requiring the CMOS image sensor to adopt a rolling shutter. Existing visible light communication (VLC) systems such as figure 1 As shown, the transmitter uses an LED light source driven by on-off keying (OOK), and the receiver uses a rolling shutter CMOS image sensor to form a light and dark fringe picture, and then obtains the OOK light information through image processing of the light and dark fringe picture. figure 1 The proposed system and decoding method...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the shortcomings of unsatisfactory reliability or high computational complexity described in the above-mentioned prior art, the present invention proposes a detection method for bright and dark fringe information with high reliability and a wider modulation frequency range

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