High dynamic range

About: High dynamic range is a research topic. Over the lifetime, 4280 publications have been published within this topic receiving 76293 citations. The topic is also known as: HDR.

Switchable Temporal Propagation Network

Abstract: Videos contain highly redundant information between frames. Such redundancy has been extensively studied in video compression and encoding, but is less explored for more advanced video processing. In this paper, we propose a learnable unified framework for propagating a variety of visual properties of video images, including but not limited to color, high dynamic range (HDR), and segmentation information, where the properties are available for only a few key-frames. Our approach is based on a temporal propagation network (TPN), which models the transition-related affinity between a pair of frames in a purely data-driven manner. We theoretically prove two essential factors for TPN: (a) by regularizing the global transformation matrix as orthogonal, the "style energy" of the property can be well preserved during propagation; (b) such regularization can be achieved by the proposed switchable TPN with bi-directional training on pairs of frames. We apply the switchable TPN to three tasks: colorizing a gray-scale video based on a few color key-frames, generating an HDR video from a low dynamic range (LDR) video and a few HDR frames, and propagating a segmentation mask from the first frame in videos. Experimental results show that our approach is significantly more accurate and efficient than the state-of-the-art methods.

Absolute profile measurement of large moderately flat optical surfaces with high dynamic range.

Abstract: We present a novel procedure for absolute, highly-accurate profile measurement with high dynamic range for large, moderately flat optical surfaces. The profile is reconstructed from many sub-profiles measured by a small interferometer which is scanned along the specimen under test. Additional angular and lateral distance measurements are used to account for the tilt of the interferometer and its precise lateral location during the measurements. Accurate positioning of the interferometer is not required. The algorithm proposed for the analysis of the data allows systematic errors of the interferometer and height offsets of the scanning stage to be eliminated and it does not reduce the resolution. By utilizing a realistic simulation scenario we show that accuracies in the nanometer range can be reached.

High dynamic range image tone mapping based on asymmetric model of retinal adaptation

Abstract: Global tone mapping operators using the symmetrical retinal response model to light tend to produce a low dynamic range (LDR) image that exhibits loss of details of its corresponding high dynamic range (HDR) image in a bright or dark area. In this paper, we introduce a new asymmetric sigmoid curve (ASC) based on the model of retinal adaptation encompassing symmetrical S-shaped curve, and present two global tone mapping operators by using the ASC. In the proposed method, an ASC-based tone mapping function is obtained by using a well-known classic photography technique, called zone system. In addition, a contrast-enhancing tone mapping function is introduced by formulating a bi-criteria optimization problem with the luminance histogram of an input HDR image and the ASC-based mapping function. Experimental results demonstrate that the proposed method enhances the global contrast while preserving image details in the tone-mapped LDR image. Moreover, the objective assessment results using an image quality metric indicate that the proposed method shows a high performance to state-of-the-art global tone mapping operators.

An ULV PWM CMOS Imager With Adaptive-Multiple-Sampling Linear Response, HDR Imaging, and Energy Harvesting

Abstract: This paper presents an ultra-low-voltage (ULV) $300\times 200$ pixel pulsewidth-modulation (PWM) CMOS imager with monitoring and capturing for Internet-of-Things (IoT) and artificial intelligent (AI) applications, fabricated in the CMOS 0.18- $\mu \text{m}$ standard process technology. In always-ON monitoring operation, the imager provides high dynamic range (HDR) and energy harvesting (EH) modes for event detection and energy collection, respectively. In low-power image capturing operation, the imager provides a linear-response (LR) mode for object identification and recording. In the LR mode, the proposed ULV PWM pixel with threshold variation cancellation (TVC) achieves a non-linearity of +0.36/−0.29% and a fixed-pattern noise (FPN) of 0.159%. With the proposed pixel-wise adaptive-multiple-sampling (AMS) scheme and the corresponding $n$ -time multiple sampling using dual-slope ramping (DSR) reference, the 0.4-V-operated PWM pixel achieves a total noise of 9.42e− at 4-time AMS operation. The achieved peak signal-to-noise ratio (PSNR) and dynamic range (DR) are 60.1 dB in the LR mode and 141 dB in the HDR mode, respectively, and the harvested power is 15.5 $\mu \text{W}$ at 60 klx in the EH mode.

W-CDMA SiGe TX-IC with high dynamic range and high power control accuracy

Abstract: This paper demonstrates the SiGe TX-IC for W-CDMA mobile terminals. For the TX-IC, a novel architecture of a variable gain amplifier is proposed to improve dynamic range and power control accuracy. With the 0.5 /spl mu/m SiGe BiCMOS technology, this TX-IC achieved over 100 dB dynamic ranges within /spl plusmn/1.5dB accuracy over all temperatures. Output power of 7 dBm can be achieved by employment of P-MOSFET current mirror type self bias control circuit for the driver amplifier. Measurement results also satisfy the specification defined by 3GPP.