Improved Shi-Tomasi sub-pixel corner detection based on super-wide field of view infrared images.

In this work, we propose a new, to the best of our knowledge, corner point detection method for a super-wide field of view infrared imaging system. First, the edge of the checkerboard calibration board is detected at the pixel level by morphological operation. Second, the interpolation technique is used to refine the edge so that the edge has sub-pixel accuracy. We obtain the four checkerboard unit corners near the real corner point and average the coordinates of the four corners to indirectly obtain the coordinates of the real corner point. Meanwhile, we take pictures of the same calibration board at different angles for repeatability verification. It is proved that the improvement of our algorithm for the detection of corners of super-wide field of view infrared images is more feasible compared to the traditional algorithms.

An alternative to opioid-based intravenous patient controlled analgesia in severe burn patients undergoing full thickness split graft in upper limbs.

BACKGROUND: Opioids provide good analgesic effect in burn patients during acute phase, but these patients may develop tolerance after prolonged exposure. Alternative analgesic strategies such as peripheral nerve blocks appear to provide adequate pain control while sparing opioid-related side effects. The purpose of this study was to evaluate intravenous patient-controlled analgesia (IV-PCA) and continuous peripheral nerve block (CPNB-PCA) in severe burn patients with relatively young age undergoing repeated debridement and large-area full thickness skin graft (FTSG). METHODS: The records of victims in dust explosion in Taiwan in 2016 from Chang Gung Memorial Hospital Pain Service Database between 2016 June and 2017 December were evaluated. The patients' demographic data including age, gender, weight, burn area, degree of burn, type of PCA regimen (IV-PCA versus CPNB-PCA), size of FTSG, and adverse effects were collected. RESULTS: The total in-hospital morphine consumption was significantly lower in CPNB-PCA than IV-PCA group. A trend of decrease in numerical rating scores (NRS) was observed for both groups and CPNB group had comparable NRS than IV-PCA group at rest. On movement, CPNB grouped had significantly lower NRS than IV-PCA on post-operative day 3. CONCLUSION: Our study demonstrated that in patients requiring high dosage of opioid, CPNB may be a suitable alternative for pain control.

Detection model and performance evaluation for the infrared search and tracking system.

To effectively evaluate the detection capability of the infrared search and tracking system (IRST), the mathematical models of target infrared (IR) radiation intensity envelope, atmospheric transmittance, and signal-to-noise ratio (SNR) operating range are improved, respectively. Based on the above three models, the IRST performance evaluation simulation system is designed to analyze the optimal detection point and effective detection area under different conditions (such as target speed, detection angle, detection probability, false alarm probability, and operating range). Meanwhile, in order to verify the validity of the model, the range evaluation method of calibration and cross-validation is proposed. And taking the cross-validation method as the baseline, the error of the optimized mathematical model of IRST in this paper is within 10%. The research results are of reference significance for IRST operating range evaluation, design, and use.

Fusion of Infrared and Visible Images Based on Three-Scale Decomposition and ResNet Feature Transfer.

Image fusion technology can process multiple single image data into more reliable and comprehensive data, which play a key role in accurate target recognition and subsequent image processing. In view of the incomplete image decomposition, redundant extraction of infrared image energy information and incomplete feature extraction of visible images by existing algorithms, a fusion algorithm for infrared and visible image based on three-scale decomposition and ResNet feature transfer is proposed. Compared with the existing image decomposition methods, the three-scale decomposition method is used to finely layer the source image through two decompositions. Then, an optimized WLS method is designed to fuse the energy layer, which fully considers the infrared energy information and visible detail information. In addition, a ResNet-feature transfer method is designed for detail layer fusion, which can extract detailed information such as deeper contour structures. Finally, the structural layers are fused by weighted average strategy. Experimental results show that the proposed algorithm performs well in both visual effects and quantitative evaluation results compared with the five methods.

Robust registration for ultra-field infrared and visible binocular images.

The ultra-field infrared and visible image registration is a challenging task due to its nonlinear imaging and multi-modal image features. In this paper, a robust registration method is proposed for the ultra-field infrared and visible images. First, control points are extracted utilizing phase congruency and optimized based on the guidance map, which is proposed according to significant structures information. Second, ROI pair matching is accomplished based on epipolar curve. Its effect is equivalent to a search window that is popular in methods with the standard field of view, and it can overcome the content differences in the search window caused by nonlinear imaging and vision disparity. Third, a descriptor, named multiple phase congruency directional pattern (MPCDP), is established and composed of distribution information and main direction. The phase congruency amplitudes are encoded as binary patterns, and then they are represented as weighted histogram for distribution information. Six pairs of ultra-field infrared and visible images are employed for registration experiments, and the results demonstrate that the performance of the proposed is robust and accurate in five types of ultra-field scenes and two different camera relationships.

Plane chessboard-based calibration method for a LWIR ultra-wide-angle camera.

A method is proposed to calibrate the long-wave infrared ultra-wide-angle camera in this paper. In addition, a novel calibration chessboard is designed and an advanced chessboard corner positioning method is adopted to improve the calibration precision. The designed calibration chessboard can achieve high thermal infrared contrast and exhibits outstanding stability, which is made of a thermoelectric semiconductor refrigeration device. The proposed subpixel corner positioning method can accurately locate the corners on the calibration chessboard according to the characteristics of the infrared image and the checkerboard pattern. Both the principle of the proposed infrared chessboard and the subpixel corner positioning procedure were presented, and the calibration experiment showed that the mean reprojection error and the root mean square error were reduced to 0.32 pixel and 0.39 pixel, respectively. Comparison studies were also performed to verify the calibration effect of the proposed method, and the possibilities of camera calibration error of the proposed method were analyzed.

The Plant Circadian Clock and Chromatin Modifications.

The circadian clock is an endogenous timekeeping network that integrates environmental signals with internal cues to coordinate diverse physiological processes. The circadian function depends on the precise regulation of rhythmic gene expression at the core of the oscillators. In addition to the well-characterized transcriptional feedback regulation of several clock components, additional regulatory mechanisms, such as alternative splicing, regulation of protein stability, and chromatin modifications are beginning to emerge. In this review, we discuss recent findings in the regulation of the circadian clock function in Arabidopsis thaliana. The involvement of chromatin modifications in the regulation of the core circadian clock genes is also discussed.

Correction method for fisheye image based on the virtual small-field camera.

A distortion correction method for a fisheye image is proposed based on the virtual small-field (SF) camera. The correction experiment is carried out, and a comparison is made between the proposed method and the conventional global correction method. From the experimental results, the corrected image by this method satisfies the law of perspective projection, and the image looks as if it was captured by an SF camera with the optical axis pointing at the corrected center. This method eliminates the phenomena of center compression, edge stretch, and field loss, and the image character is more obvious, which benefits the afterward target detection and information extraction.

Method for calibrating the fisheye distortion center.

A simple method is proposed to calibrate the fisheye distortion center, which synthesizes the algorithms of the ellipse fitting and gaussian surface fitting. Through analyzing the imaging projection of the equidistant fisheye lens, the calibration principle is introduced in detail. From the experimental results, we find that ellipse fitting error and the relative error of gaussian surface fitting are less than 0.06 pixels and 1.5%, respectively, and the proposed method has a higher calibration precision and stability compared with the methods in the inferences. Besides, the proposed method does not rely on any particular distortion model and other fisheye parameters, and only the image information of the calibration board is utilized, which reduces the calibration complexity and is suitable for the center calibration of any equidistant fisheye camera.