This paper presents a significant contribution to high-fidelity audio technology through the comprehensive design and implementation of an advanced audio-grade preamplifier integrated with a ...high-performance digital-to-analog converter (DAC). The versatility of the digital section allows seamless integration of audio sources from Universal Serial Bus (USB), Bluetooth, or Sony-Philips Digital interface (SPDIF). In addition, the preamplifier accommodates various analog sources, offering flexibility to users. The unique architecture features an innovative resistor network-based DAC and precision components in the analog section, paving the way for achieving unparalleled audio fidelity. The measured distortion values are remarkably low, with a total harmonic distortion plus noise (THD+N) of only 0.03%. Furthermore, the system exhibits a signal-to-noise ratio (SNR) of 87 dB, comparable to industry benchmark. The hardware design sections went into meticulous details, providing an in-depth exploration of each block of the project. The inclusion of test and measurement data from the actual prototype enhances the credibility of the proposed work. This research not only showcases the theoretical operation of the preamplifier and DAC stage but also validates the practical implementation through many rounds of testing and validation. Our proposed work contributes to the field of high-fidelity audio by presenting a novel solution that is comparable to industry standards. The design’s adaptability to many different audio sources, coupled with robust performance metrics, positions it as a benchmark in the field of audio reproduction. The measurement results and findings presented in this paper are poised to influence future advancements in HiFi audio technology.
Chronic neck pain (CNP) is a prevalent musculoskeletal condition including notable impairments in respiratory function. The diaphragm, serving dual roles in respiration and spinal stability, is ...intricately linked to the cervical spine through fascial, neurophysiological, and biomechanical connections. However, to date, none has investigated the diaphragm function in patients with CNP.
To investigate the diaphragm function, respiratory muscle strength, and pulmonary function in patients with CNP. In addition, their associations were also examined.
A case-control study.
A total of 54 participants were recruited including 25 patients with CNP (CNP group) and 29 healthy adults (CON group). Pulmonary function including forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), and respiratory muscle strength represented by maximal inspiratory (MIP) and maximal expiratory pressure (MEP), as well as diaphragm function including ultrasonographic measures of mobility and thickness changes during maximal inspiration and expiration were assessed in all participants. Additionally, the intensity of pain and disability were evaluated using a Visual Analog Scale and Neck Disability Index only in patients with CNP.
Significant reductions of the FVC, FEV1, MIP, and MEP were found in the CNP group compared to the CON group (p < 0.05). The diaphragm mobility and thickness changes were also significantly decreased in the CNP group than the CON group with medium effect sizes (p < 0.05). Only diaphragm thickness change was positively correlated with FVC, FEV1, and MEP in patients with CNP. Furthermore, MEP showed the strongest contribution to diaphragm thickness change based on the regression analysis.
Impaired diaphragm function, respiratory muscle strength, and pulmonary function were observed in patients with CNP. Patients with smaller diaphragm thickness change had poorer pulmonary function and reduced maximal expiratory muscle strength. Diaphragm assessment and intervention may be considered in CNP management.
•First study reported ultrasonographic diaphragm function in chronic neck pain.•Reduced diaphragm mobility and thickness changes during respiratory.•Reduced respiratory muscle strength and pulmonary function.
We present Steadiface, a new real-time face-centric video stabilization method that simultaneously removes hand shake and keeps subject's head stable. We use a CNN to estimate the face landmarks and ...use them to optimize a stabilized head center. We then formulate an optimization problem to find a virtual camera pose that locates the face to the stabilized head center while retains smooth rotation and translation transitions across frames. We test the proposed method on fieldtest videos and show it stabilizes both the head motion and background. It is robust to large head pose, occlusion, facial appearance variations, and different kinds of camera motions. We show our method advances the state of art in selfie video stabilization by comparing against alternative methods. The whole process runs very efficiently on a modern mobile phone (8.1 ms/frame).
This paper presents three novel schemes for integrating digital stabilizer with video codec of a digital video camera, each designed for a different application scenario. Scheme 1 confines the global ...motion estimation (ME) to within a small background region determined by clustering the motion vectors (MVs) generated by the video encoder. Scheme 2 performs the main ME task at the digital stabilizer and sends the resulting motion vectors to the video encoder, where the motion vectors are further refined to subpixel accuracy. Scheme 3, which is applied on the decoder side, acquires the motion information directly from the video decoder to perform digital stabilization. These integration schemes achieve computational efficiency without affecting the performance of video coding and digital stabilization.
Real- Time Video Denoising on Mobile Phones Ehmann, Jana; Chu, Lun-Cheng; Tsai, Sung-Fang ...
2018 25th IEEE International Conference on Image Processing (ICIP),
2018-Oct.
Conference Proceeding
We present an algorithm for real-time video denoising on mobile platforms. Based on Gaussian-Laplacian pyramid decomposition, our solution's main contributions are fast alignment and a new ...interpolation function that fuses noisy frames into a denoised result. The interpolation function is adaptive to local and global properties of the input frame, robust to motion alignment errors, and can be computed efficiently. We show that the proposed algorithm has comparable quality to offline high-quality video denoising methods, but is orders of magnitude faster. On a modern mobile platform, our work takes less than 20ms to process one HD frame, and it achieves the highest score on a public benchmark.
In this paper, we investigate the assessment of image realism by focusing our attention on the color compatibility between an inserted object and the background in an image composite. We propose a ...technique based on two color compatibility properties to achieve realistic image composition. The first property is related to the color similarity, and the second one to the consistence of color tendency between image regions. We further propose algorithms based on these two properties for image realism assessment and recoloring. These algorithms only require information from the image to be tested, making them suitable for practical applications where real images are unavailable. Effectiveness of the algorithms is demonstrated through various images and verified by ground truth.
Closing up onto our sun: solar imaging Shrivastava, Kushagra; Chia, Keith Wen Kai; Wong, Kang Jun ...
EPJ Web of Conferences,
2020, Letnik:
240
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Solar activity research provides insight into the Sun’s past, future (Science Daily, 2018). The solar activity includes observations of large numbers of intense sunspots, flares, and other phenomena; ...and demands a wide range of techniques and measurements on the observations. This research needs long term data collection before critical analyses can occur, to generate meaningful learning and knowledge. In this project, we will use solar imaging to make observations of solar activity, and take our baby steps to make contributions in citizen science. Observations will be made in 3 wavelengths to gain a more thorough analysis by looking at different perspectives of the Sun, namely H-Alpha, Calcium-K, and white light.
Recent proliferation of camera phones, photo sharing and social network services has significantly changed how we process our photos. Instead of going through the traditional download‐edit‐share ...cycle using desktop editors, an increasing number of photos are taken with camera phones and published through cellular networks. The immediacy of the sharing process means that on‐device image editing, if needed, should be quick and intuitive. However, due to the limited computational resources and vastly different user interaction model on small screens, most traditional local selection methods can not be directly adapted to mobile devices. To address this issue, we present TouchTone, a new method for edge‐aware image adjustment using simple finger gestures. Our method enables users to select regions within the image and adjust their corresponding photographic attributes simultaneously through a simple point‐and‐swipe interaction. To enable fast interaction, we develop a memory‐ and computation‐efficient algorithm which samples a collection of 1D paths from the image, computes the adjustment solution along these paths, and interpolates the solutions to entire image through bilateral filtering. Our system is intuitive to use, and can support several local editing tasks, such as brightness, contrast, and color balance adjustments, within a minute on a mobile device.
Motion blur of fast-moving subjects is a longstanding problem in photography and very common on mobile phones due to limited light collection efficiency, particularly in low-light conditions. While ...we have witnessed great progress in image deblurring in recent years, most methods require significant computational power and have limitations in processing high-resolution photos with severe local motions. To this end, we develop a novel face deblurring system based on the dual camera fusion technique for mobile phones. The system detects subject motion to dynamically enable a reference camera, e.g., ultrawide angle camera commonly available on recent premium phones, and captures an auxiliary photo with faster shutter settings. While the main shot is low noise but blurry (Figure 1(a)), the reference shot is sharp but noisy (Figure 1(b)). We learn ML models to align and fuse these two shots and output a clear photo without motion blur (Figure 1(c)). Our algorithm runs efficiently on Google Pixel 6, which takes 463 ms overhead per shot. Our experiments demonstrate the advantage and robustness of our system against alternative single-image, multi-frame, face-specific, and video deblurring algorithms as well as commercial products. To the best of our knowledge, our work is the first mobile solution for face motion deblurring that works reliably and robustly over thousands of images in diverse motion and lighting conditions.
DSLR cameras can achieve multiple zoom levels via shifting lens distances or swapping lens types. However, these techniques are not possible on smartphone devices due to space constraints. Most ...smartphone manufacturers adopt a hybrid zoom system: commonly a Wide (W) camera at a low zoom level and a Telephoto (T) camera at a high zoom level. To simulate zoom levels between W and T, these systems crop and digitally upsample images from W, leading to significant detail loss. In this paper, we propose an efficient system for hybrid zoom super-resolution on mobile devices, which captures a synchronous pair of W and T shots and leverages machine learning models to align and transfer details from T to W. We further develop an adaptive blending method that accounts for depth-of-field mismatches, scene occlusion, flow uncertainty, and alignment errors. To minimize the domain gap, we design a dual-phone camera rig to capture real-world inputs and ground-truths for supervised training. Our method generates a 12-megapixel image in 500ms on a mobile platform and compares favorably against state-of-the-art methods under extensive evaluation on real-world scenarios.
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