Fig 1.
Correlation between image denoising and image processing.
Fig 2.
Ridge wave transformation flowchart.
Fig 3.
Flow of wavelet threshold denoising.
Fig 4.
The diagram of Hard TA and Soft TA.
Fig 5.
The improved Hard TA and Soft TA.
Fig 6.
Block ridge wave denoising flowchart.
Fig 7.
A hybrid algorithm based on improved threshold function and wavelet transform.
Fig 8.
Comparison results of PSNR and MSE of gray images under different algorithms.
Fig 9.
Comparison results of PSNR and MSE of color images under different algorithms.
Fig 10.
Three images of fingerprint patterns.
Table 1.
Denoising evaluation indicators for fingerprint images using different algorithms.
Table 2.
Structural changes of images after denoising using different algorithms.
Fig 11.
Image smoothness of different methods.
Fig 12.
The SSIM for the different algorithms.
Fig 13.
Time spent on image denoising using different algorithms.
Fig 14.
Similarity error of different methods.
Fig 15.
Comparison of image denoising results between two algorithms.
Fig 16.
Comparison of denoising effects of different algorithms.