High accuracy sub-pixel image registration under noisy condition

• Published in: 2015 IEEE International Symposium on Circuits and Systems (ISCAS) pp. 1674 - 1677
• Main Authors: Qiang Song, Ruiqin Xiong, Siwei Ma, Xiaopeng Fan, Wen Gao
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.05.2015
• Subjects: distribution of the phase change; Frequency-domain analysis; Image registration; Least squares approximations; Noise measurement; Noise robustness; Noisy image registration; phase difference plane; Signal to noise ratio; weighted least squares
• ISSN: 0271-4302; 2158-1525
• DOI: 10.1109/ISCAS.2015.7168973

Image registration plays an important role in many image processing applications. A key problem is that the accuracy of registration can be severely affected by noise. This paper presents a sub-pixel registration method for noisy images. In particular, we investigate how to estimate transitional shift to a high precision using the noisy phase data in frequency domain. Based on theoretical analysis, we find that the noise-caused phase change for every frequency component of high signal-to-noise ratio (SNR) can be well approximated by a Gaussian distribution. Furthermore, we show that the reliability of phase data can also be measured by the SNR of corresponding frequency component. A noise-robust registration framework is proposed to utilize high-SNR frequency components adaptively, while masking out the components of SNR lower than a threshold. Experiments demonstrate that the proposed method is superior to existing image registration methods in the presence of noise.