Multi-Spectral Fusion and Denoising of Color and Near-Infrared Images Using Multi-Scale Wavelet Analysis

We formulate multi-spectral fusion and denoising for the luminance channel as a maximum a posteriori estimation problem in the wavelet domain. To deal with the discrepancy between RGB and near infrared (NIR) data in fusion, we build a discrepancy model and introduce the wavelet scale map. The scale map adjusts the wavelet coefficients of NIR data to have the same distribution as the RGB data. We use the priors of the wavelet scale map and its gradient as the contrast preservation term and gradient denoising term, respectively. Specifically, we utilize the local contrast and visibility measurements in the contrast preservation term to transfer the selected NIR data to the fusion result. We also use the gradient of NIR wavelet coefficients as the weight for the gradient denoising term in the wavelet scale map. Based on the wavelet scale map, we perform fusion of the RGB and NIR wavelet coefficients in the base and detail layers. To remove noise, we model the prior of the fused wavelet coefficients using NIR-guided Laplacian distributions. In the chrominance channels, we remove noise guided by the fused luminance channel. Based on the luminance variation after fusion, we further enhance the color of the fused image. Our experimental results demonstrated that the proposed method successfully performed the fusion of RGB and NIR images with noise reduction, detail preservation, and color enhancement.

Medium and time conservation affect follicular morphology and superoxide dismutase enzyme activity of bovine preantral follicles during storage at 4ºC

The aim of this study was to evaluate the morphology and superoxide dismutase enzyme (SOD) activity of bovine preantral follicles (PFs) preserved in TCM 199, saline solution or PBS at different conservation periods. Cow ovaries (n=6) were divided into 7 fragments. One small piece of each ovarian fragment was randomly removed to evaluate SOD activity, while the remainder was immediately fixed for morphological evaluation as a control group. The other 6 fragments were randomly distributed in tubes containing TCM 199, saline solution, or PBS and maintained at 4ºC for 6 or 24 h. For histological evaluation, the fragments were fixed in Carnoy and stained with PAS-hematoxylin, following being classified PFs in relation to their follicular morphology in normal or degenerated. Determination of SOD activity was based on the ability to inhibit autoxidation of adrenaline in adrenochrome. Evaluation of follicular morphology showed that follicles preserved in TCM 199 for 6 h did not differ from the control (P > 0.05). In contrast, preservation in saline solution and PBS for 6 or 24 h and TCM 199 for 24 h decreased normal PFs compared to the control (P < 0.05). SOD showed a lower activity in ovarian cortical tissue kept in TCM 199 for 6 h and saline solution for 24 h than in the other groups. Our study shows that incubation using TCM 199 at 4°C for 6 h can be used to efficiently conserve female bovine PFs in situ.

Neutralisation and contrast preservation

This paper studies the contextual variation in the voicing properties of three-consonant clusters (CC#C) in Hungarian. We investigate the velar+alveolar stop clusters /kt/ and /ɡd/, and the alveolar fricative+stop clusters /st/ and /zd/ in potentially voicing-neutralising and assimilating contexts. We show that in these contexts, regressive voicing assimilation in Hungarian is categorical, but partially contrast preserving, and that stops and fricatives are not affected in the same way. Fricatives resist voicing before a voiced obstruent and are devoiced utterance-finally. This is a phonetically unfavourable position, therefore other duration-related cues step up to prevent complete laryngeal neutralisation.

Single Image Super-Resolution Algorithm Possessing Edge and Contrast Preservation

In real time surveillance video applications, it is often required to identify a region of interest in a degraded low resolution (LR) image. State-of-the-art super-resolution (SR) techniques produce images with poor illumination and degraded high frequency details. In this paper, we present a different approach for SISR by correcting the dual-tree complex wavelet transform (DT-CWT) subbands using the multi-stage cascaded joint bilateral filter (MSCJBF) and singular value decomposition (SVD). The proposed method exploits geometric regularity for implementing the covariance-based interpolation in the spatial domain. We decompose the interpolated LR image into different image and wavelet coefficients by employing DT-CWT. To preserve edges, we alter the wavelet sub-bands with the high frequency details obtained from the MSCJBF. Simultaneously, we retain uniform illumination by improving the image coefficients using SVD. In addition, the wavelet sub-bands undergo lanczos interpolation prior to the subband refinement. Experimental results demonstrate the effectiveness of our method.

Environmental shielding is contrast preservation

The term ‘environmental shielding’ has been used to refer to a class of processes in which the phonetic realisation of a nasal stop depends on its vocalic context. In Chiriguano, for example, nasal consonants are realised as such before nasal vowels (/mã/ → [mã]), but acquire an oral release before oral vowels (/ma/ → [mba]). Herbert (1986) claims that shielding protects a contrast between oral and nasal vowels: if Chiriguano /ma/ were realised as [ma], [a] would likely carry some degree of nasal coarticulation, and be less distinct from nasal /ã/. This article provides new arguments for Herbert's position, drawn from a large typological study of South American languages. I argue that environmental shielding is contrast preservation, and that any successful analysis of shielding must make explicit reference to contrast. These results contribute to a growing body of evidence that constraints on contrast are an essential component of phonological theory.