5.3 Physical Anti-Collision Based on Wavelet
187
Fig. 5.26 Denoising results of different denoising methods. a Wavelet threshold denoising results
by using db2 function. b Wavelet threshold denoising results by using sym4 function. c Wiener
filter denoising results. d Median filter denoising results
Table 5.4 Objective quality
evaluation of denoising
methods results
Denoising methods
SNR/dB
Experimental initial image
5.3862
Wavelet threshold denoising method by using db2
function
13.3086
Wavelet threshold denoising method by using sym4
function
13.3132
Wiener filter denoising method
13.1488
Median filter denoising method
11.3075
Therefore, the author uses sym4 wavelet threshold denoising method to denoise the
noisy images.
(2) Image matching
After denoising noisy images, in order to conduct the 3D coordinates measurement
of the RFID tags, the obtained images of the RFID tags are matched. In this paper,
a template matching method is used to match the tag images. Firstly, we select an