ABSTRACT
In video processing, background initialization aims to obtain a scene without foreground objects. Recently, the background initialization problem has attracted the attention of researchers because of its real-world applications, such as video segmentation, computational photography, video surveillance, etc. However, the background initialization problem is still challenging because of the complex variations in illumination, intermittent motion, camera jitter, shadow, etc. This paper proposes a novel and effective background initialization method using singular spectrum analysis. Firstly, we extract the video's color frames and split them into RGB color channels. Next, RGB color channels of the video are saved as color channel spatio-temporal data. After decomposing the color channel spatio-temporal data by singular spectrum analysis, we obtain the stable and dynamic components using different eigentriple groups. Our study indicates that the stable component contains a background image and the dynamic component includes the foreground image. Finally, the color background image is reconstructed by merging RGB color channel images obtained by reshaping the stable component data. Experimental results on the public scene background initialization databases show that our proposed method achieves a good color background image compared with state-of-the-art methods.
ABSTRACT
BACKGROUND: Autoimmune thyroid disease (AITD) often coexists with pernicious anemia (PA) among whites. The study aimed to determine thyroid autoimmunity in Chinese patients with PA. METHODS: From the data of a hospital-based longitudinal study of Chinese PA patients (1994-2007), those with complete information of antibodies to thyroid peroxidase (TPO), thyroglobulin (Tg), and gastric parietal cell; serum thyroid-stimulating hormone and free thyroxine; gastric mucosal histology; and family history of AITD were analyzed. RESULTS: Among 126 Chinese PA patients, 44% had TPO/Tg antibodies and 13.5% AITD. TPO/Tg antibodies occurred in 33% (16 of 49) of male and 52% (40 of 77) of female patients (P = 0.034). Graves disease (8 patients) tended to antedate PA and was associated with no or low titers of TPO/Tg antibodies. Primary hypothyroidism (9 patients) developed during follow-up and was associated with high TPO/Tg antibody titers. The TPO/Tg antibodies did not affect the clinical course of PA but was associated with an enhanced risk of developing AITD and vitiligo. Overall, AITD (before and after PA) occurred in 23% (13 of 56) and 5.7% (4 of 70) of PA patients with and without antibodies (P = 004). During follow-up (mean duration of 75.24 +/- 46.39 months), 10 patients developed AITD-7 new onset of hypothyroidism and 3 progression/relapse of prior AITD. Logistic regression analysis of presenting features of PA revealed 2 independent factors for AITD development during follow-up-presence of thyroid antibodies (odds ratio 20.2, 95% confidence interval 1.8-223) and history of prior AITD (odds ratio 39.8, 95% confidence interval 2.3-679). CONCLUSION: It is recommended to screen thyroid antibodies and monitor thyroid function during follow-up.
