Motion Compensation Technique Research Articles

A hybrid block-based motion estimation algorithm using JAYA for video coding techniques

In any video coding solution, motion estimation (ME) and motion compensation (MC) techniques are widely used and they play an inevitable role in reducing the temporal redundancies between successive frames. Block-based motion estimation (BME) is one of the widely utilized techniques in the recently developed video compression standards by JCT-VC including HEVC due to its efficacy and ease of implementation. In BME, the frames in a video sequence are partitioned into a number of non-overlapping blocks. Then, for each of the blocks, a best-matched block is obtained within a definite search region in the reference frame to minimize certain cost function or fitness value such as the sum of absolute difference (SAD), mean of absolute difference (MAD), or mean square error (MSE). However, the key challenge lies in the evaluation of these cost functions, since they are computationally expensive and involves the most time-taking operations in the BME process. Hence, BME-based approaches can be viewed as an optimization problem and meta-heuristic algorithms can be effectively exploited for the problem under consideration. In this paper, a hybrid BME technique using a recently developed optimization algorithm, namely, JAYA algorithm, is proposed. Besides this proposal, several other modules, namely, the fitness approximation technique, search history preservation, and early & adaptive termination criterion are utilized. The main objective behind the use of the aforementioned modules is to avoid the unnecessary evaluation of the fitness function. Exhaustive simulations are carried out to demonstrate the efficacy of the proposed method over that of the benchmark schemes with respect to different performance measures, namely, the peak signal-to-noise ratio (PSNR), PSNR degradation ratio (DPSNR), search efficiency, structural similarity index measure (SSIM), and computation time. Comparative analysis and quantitative evaluation clearly show that the present technique produces more reliable motion vectors with competitive time complexity as compared to that of the benchmark schemes.

Automated quantification and evaluation of motion artifact on coronary CT angiography images.

This study developed and validated a Motion Artifact Quantification algorithm to automatically quantify the severity of motion artifacts on coronary computed tomography angiography (CCTA) images. The algorithm was then used to develop a Motion IQ Decision method to automatically identify whether a CCTA dataset is of sufficient diagnostic image quality or requires further correction. The developed Motion Artifact Quantification algorithm includes steps to identify the right coronary artery (RCA) regions of interest (ROIs), segment vessel and shading artifacts, and to calculate the motion artifact score (MAS) metric. The segmentation algorithms were verified against ground-truth manual segmentations. The segmentation algorithms were also verified by comparing and analyzing the MAS calculated from ground-truth segmentations and the algorithm-generated segmentations. The Motion IQ Decision algorithm first identifies slices with unsatisfactory image quality using a MAS threshold. The algorithm then uses an artifact-length threshold to determine whether the degraded vessel segment is large enough to cause the dataset to be nondiagnostic. An observer study on 30 clinical CCTA datasets was performed to obtain the ground-truth decisions of whether the datasets were of sufficient image quality. A five-fold cross-validation was used to identify the thresholds and to evaluate the Motion IQ Decision algorithm. The automated segmentation algorithms in the Motion Artifact Quantification algorithm resulted in Dice coefficients of 0.84 for the segmented vessel regions and 0.75 for the segmented shading artifact regions. The MAS calculated using the automated algorithm was within 10% of the values obtained using ground-truth segmentations. The MAS threshold and artifact-length thresholds were determined by the ROC analysis to be 0.6 and 6.25mm by all folds. The Motion IQ Decision algorithm demonstrated 100% sensitivity, 66.7%±27.9% specificity, and a total accuracy of 86.7%±12.5% for identifying datasets in which the RCA required correction. The Motion IQ Decision algorithm demonstrated 91.3% sensitivity, 71.4% specificity, and a total accuracy of 86.7% for identifying CCTA datasets that need correction for any of the three main vessels. The Motion Artifact Quantification algorithm calculated accurate (<10% error) motion artifact scores using the automated segmentation methods. The developed algorithms demonstrated high sensitivity (91.3%) and specificity (71.4%) in identifying datasets of insufficient image quality. The developed algorithms for automatically quantifying motion artifact severity may be useful for comparing acquisition techniques, improving best-phase selection algorithms, and evaluating motion compensation techniques.

View synthesis method for 3D video coding based on temporal and inter view correlation

Recently, in three-dimensional (3D) television, the temporal correlation between consecutive frames of the intermediate view is used together with the inter-view correlation to improve the quality of the synthesised view. However, most temporal methods are based on the motion vector fields (MVFs) calculated by the optical flow or block-based motion estimation which has very high computational complexity. To alleviate this issue, the authors propose a temporal-disparity-based view synthesis (TDVS) method, which uses the MVFs extracted from the bitstreams of side views and motion warping technique to create the temporal correlation between views in the intermediate position. Then a motion compensation technique is used to create a temporal-based view. Finally, the temporal-based view is fused with a disparity-based view which is generated by a traditional depth image-based rendering technique to create the final synthesised view. The fusion of these views is performed based on the side information which is determined and encoded at the sender-side of the 3D video system using a dynamic programming algorithm and rate-distortion optimisation scheme. Experimental results show that the proposed method can achieve the synthesised view with appreciable improvements in comparison with the view synthesis reference software 1D fast (VSRS-1D Fast) for several test sequences.

Application of preprocessing methods to improve time delay estimation for synthetic aperture sonar motion estimation

Synthetic aperture sonar (SAS) provides the best opportunity for side-looking sonar mounted on unmanned underwater vehicles to achieve high-resolution images at longer ranges. However, SAS processing requires maintaining a coherent phase history over the entire synthetic aperture, driving strict constraints on resolvable platform motion. This has driven the development of motion estimation and compensation techniques that use the received ping data, in addition to the onboard navigation solution, to resolve ping-to-ping platform motion. The most common approach is to use the redundant phase center technique. Here the ping interval is set, such that a portion of the array is overlapped. The accuracy of the motion estimation depends on the accuracy of the time delay estimation between the data received on the overlapping channels. Given the stochastic nature of the operational environment some level of decorrelation between these two signals is likely, even without residual platform motion. This decorrelation results in inaccurate time delay estimation and image quality degradation. In this research various preprocessing techniques have been applied to the sonar data to reduce the influence of stochastic noise with the goal of improving the accuracy of the time delay estimates.

Robust real-time extraction of respiratory signals from PET list-mode data

Respiratory motion, which typically cannot simply be suspended during PET image acquisition, affects lesions’ detection and quantitative accuracy inside or in close vicinity to the lungs. Some motion compensation techniques address this issue via pre-sorting (‘binning’) of the acquired PET data into a set of temporal gates, where each gate is assumed to be minimally affected by respiratory motion. Tracking respiratory motion is typically realized using dedicated hardware (e.g. using respiratory belts and digital cameras). Extracting respiratory signals directly from the acquired PET data simplifies the clinical workflow as it avoids handling additional signal measurement equipment. We introduce a new data-driven method ‘combined local motion detection’ (CLMD). It uses the time-of-flight (TOF) information provided by state-of-the-art PET scanners in order to enable real-time respiratory signal extraction without additional hardware resources.CLMD applies center-of-mass detection in overlapping regions based on simple back-positioned TOF event sets acquired in short time frames. Following a signal filtering and quality-based pre-selection step, the remaining extracted individual position information over time is then combined to generate a global respiratory signal. The method is evaluated using seven measured FDG studies from single and multiple scan positions of the thorax region, and it is compared to other software-based methods regarding quantitative accuracy and statistical noise stability.Correlation coefficients around 90% between the reference and the extracted signal have been found for those PET scans where motion affected features such as tumors or hot regions were present in the PET field-of-view. For PET scans with a quarter of typically applied radiotracer doses, the CLMD method still provides similar high correlation coefficients which indicates its robustness to noise. Each CLMD processing needed less than 0.4 s in total on a standard multi-core CPU and thus provides a robust and accurate approach enabling real-time processing capabilities using standard PC hardware.

Proposed dynamic error control techniques for QoS improvement of wireless 3D video transmission

SummaryError control techniques like error resilience (ER) and error concealment (EC) are efficient techniques to ameliorate the lost macroblocks (MBs) in the 3D video (3DV) communication system. In this paper, we propose efficient and adaptive hybrid ER‐EC algorithms for 3DV transmission over error‐prone wireless channels. At the encoder, adaptive preprocessing ER mechanisms are proposed through using the context adaptive variable length coding entropy, slice structured coding modes, and explicit flexible macroblock ordering mapping. They are used to assist the suggested EC techniques at the decoder to accurately reconstruct the erroneous MBs and frames. At the decoder, an efficient postprocessing EC technique with multiproposition methods is proposed to dynamically select the convenient EC hypothesis method based on the size of the lost MBs, the faulty view, and the frame type. It conceals the received erroneous MBs of intra‐encoded and inter‐encoded frames of the transmitted 3DV by exploiting the temporal, spatial, and inter‐view correlations among frames and views. To further improve the decoded 3DV quality, a weighted overlapping block motion and disparity compensation technique is used to reinforce the performance of the suggested ER‐EC techniques. Experimental results on various 3DV streams prove that the suggested techniques have considerably acceptable subjective and objective 3DV performance. They achieve an improved average peak signal‐to‐noise ratio gain by almost 2.85 dB compared to the conventional error control algorithms at a packet loss rate = 40%.

Proposed optimized hybrid error recovery techniques for performance improvement of wireless 3D-MVC communication

The transmission of 3D Video (3DV) over wireless channels has become a hot issue because of the limited resources and the existence of severe channel errors. In the 3DV system, the compressed bit streams may be dropped down due to the propagation of transmission errors in the time, space, and view scopes. So, it is important to recover the Disparity Vectors (DVs) and Motion Vectors (MVs) of the corrupted Macro-Blocks (MBs) at the decoder utilizing efficient Error Concealment (EC) post-processing techniques. To enhance the received 3DV quality, we suggest optimized hybrid techniques to reconstruct the erroneous MBs of color-plus-depth inter-encoded and intra-encoded frames. A hybrid approach of Circular Scan Order Interpolation (CSOI) technique and Partitioning Motion Compensation (PMC) technique is proposed for the color intra-frames loss concealment. For the corrupted color inter-frames, a joint approach of Directional Textural Motion Coherence (DTMC) technique and Directional Interpolation Error Concealment (DIEC) technique is suggested. To estimate more additional depth-aided DVs and MVs for recovering the erroneous depth frames, a depth-assisted error recovery technique is suggested. These depth-estimated motion and disparity vectors are then added together with the estimated candidate texture DVs and MVs for reconstructing the corrupted color-plus-depth frames. Finally, the best color-plus-depth MVs and DVs are chosen by the Decoder Motion Vector Estimation (DMVE) and DIEC techniques. Simulation outcomes on various 3D video frames elucidate that the suggested hybrid color plus depth EC techniques achieve high robustness at high Packet Loss Rates (PLRs).

Range-Doppler Mapping of Space-Based Targets Using the JRO 50 MHz Radar

The Jicamarca Radio Observatory (JRO) two-dimensional square array radar system operating at ~ 6-m wavelength was used to study the Moon and low Earth orbit satellites using the Range-Doppler inverse synthetic aperture radar technique also known as Delay-Doppler imaging. The radar data was collected on Oct 21, 2015. A circularly polarized coded pulse was transmitted from a quarter-array antenna segment during lunar transit over JRO. Dual-linear polarization receive systems were employed on two quarter-array segments and on two 1/64th array modules giving the longest possible baselines across the transit path. A Range-Doppler mapping technique that uses the rotational motion of the targets and an autofocusing motion and ionospheric delay compensation technique has been implemented to generate the two-dimensional maps of the point-target (Satellite) and range-spread target (Moon). A review of our technique and the maps obtained from these observations is presented herein. Range-Doppler maps of the Moon and satellites are instructive with regards to possible further improvement of the technique, especially regarding ionospheric compensation.

MRI protocol optimization for quantitative DCE-MRI of the spine

PurposeIn this study we systematically investigated different Dynamic Contrast Enhancement (DCE)-MRI protocols in the spine, with the goal of finding an optimal protocol that provides data suitable for quantitative pharmacokinetic modelling (PKM). Materials and methodsIn 13 patients referred for MRI of the spine, DCE-MRI of the spine was performed with 2D and 3D MRI protocols on a 3T Philips Ingenuity MR system. A standard bolus of contrast agent (Dotarem - 0.2ml/kg body weight) was injected intravenously at a speed of 3ml/s. Different techniques for acceleration and motion compensation were tested: parallel imaging, partial-Fourier imaging and flow compensation. The quality of the DCE MRI images was scored on the basis of SNR, motion artefacts due to flow and respiration, signal enhancement, quality of the T1 map and of the arterial input function, and quality of pharmacokinetic model fitting to the extended Tofts model. ResultsSagittal 3D sequences are to be preferred for PKM of the spine. Acceleration techniques were unsuccessful due to increased flow or motion artefacts. Motion compensating gradients failed to improve the DCE scans due to the longer echo time and the T2* decay which becomes more dominant and leads to signal loss, especially in the aorta. The quality scoring revealed that the best method was a conventional 3D gradient–echo acquisition without any acceleration or motion compensation technique. The priority in the choice of sequence parameters should be given to reducing echo time and keeping the dynamic temporal resolution below 5s. Increasing the number of acquisition, when possible, helps towards reducing flow artefacts. In our setting we achieved this with a sagittal 3D slab with 5 slices with a thickness of 4.5mm and two acquisitions. ConclusionThe proposed DCE protocol, encompassing the spine and the descending aorta, produces a realistic arterial input function and dynamic data suitable for PKM.

Robust optimization of VMAT for lung cancer: Dosimetric implications of motion compensation techniques.

In inverse planning of lung radiotherapy, techniques are required to ensure dose coverage of target disease in the presence of tumor motion as a result of respiration. A range of published techniques for mitigating motion effects were compared for dose stability across 5 breath cycles of ±2 cm. Techniques included planning target volume (PTV) expansions, internal target volumes with (OITV) and without tissue override (ITV), average dataset scans (ADS), and mini‐max robust optimization. Volumetric arc therapy plans were created on a thorax phantom and verified with chamber and film measurements. Dose stability was compared by DVH analysis in calculations across all geometries. The lung override technique resulted in a substantial lack of dose coverage (−10%) to the tumor in the presence of large motion. PTV, ITV and ADS techniques resulted in substantial (up to 25%) maximum dose increases where solid tissue travelled into low density optimized regions. The results highlight the need for care in optimization of highly heterogeneous where density variations may occur with motion. Robust optimization was shown to provide greater stability in both maximum (<3%) and minimum dose variations (<2%) over all other techniques.

Open-field mouse brain PET: design optimisation and detector characterisation

‘Open-field’ PET, in which an animal is free to move within an enclosed space during imaging, is a very promising advance for neuroscientific research. It provides a key advantage over conventional imaging under anesthesia by enabling functional changes in the brain to be correlated with an animal’s behavioural response to environmental or pharmacologic stimuli. Previously we have demonstrated the feasibility of open-field imaging of rats using motion compensation techniques applied to a commercially available PET scanner. However, this approach of ‘retro-fitting’ motion compensation techniques to an existing system is limited by the inherent geometric and performance constraints of the system. The goal of this project is to develop a purpose-built PET scanner with geometry, motion tracking and imaging performance tailored and optimised for open-field imaging of the mouse brain. The design concept is a rail-based sliding tomograph which moves according to the animal’s motion. Our specific aim in this work was to evaluate candidate scanner designs and characterise the performance of a depth-of-interaction detector module for the open-field system. We performed Monte Carlo simulations to estimate and compare the sensitivity and spatial resolution performance of four scanner geometries: a ring, parallel plate, and two box variants. Each system was based on a detector block consisting of a 23 × 23 array of 0.785 × 0.785 × 20 mm3 LSO crystals (overall dim. 19.6 × 19.6 × 20 mm). We found that a DoI resolution capability of 3 mm was necessary to achieve approximately uniform sub-millimetre spatial resolution throughout the FoV for all scanners except the parallel-plate geometry. With this DoI performance, the sensitivity advantage afforded by the box geometry with overlapping panels (16% peak absolute sensitivity, a 36% improvement over the ring design) suggests this unconventional design is best suited for imaging the mouse brain. We also built and characterised the block detector modelled in the simulations, including a dual-ended readout based on 6 × 6 arrays of through-silicon-via silicon photomultipliers (active area 84%) for DoI estimation. Identification of individual crystals in the flood map was excellent, energy resolution varied from 12.4% ± 0.6% near the centre to 24.4% ± 3.4% at the ends of the crystal, and the average DoI resolution was 2.8 mm ± 0.35 mm near the central depth (10 mm) and 3.5 mm ± 1.0 mm near the ends. Timing resolution was 1.4 ± 0.14 ns. Therefore, the DoI detector module meets the target specifications for the application and will be used as the basis for a prototype open-field mouse PET scanner.

Phase Correction of Single-Look Complex Radar Images for User-Friendly Efficient Interferogram Formation

We present a new interferometric synthetic aperture radar processing approach that removes topography–dependent phase from single-look complex (SLC) radar images, making interferogram formation more efficient. We first adopt motion compensation techniques to resample SLC images with respect to an ideal reference orbit and then separate the residual topographic phase contributions into parts dependent only on individual SLC acquisitions, and generate topography-compensated images directly in latitude–longitude coordinates. Since the number of interferograms is typically much larger than the number of SLC images, our approach greatly reduces needed computational resources. Furthermore, we move the need for precise knowledge of imaging geometry upstream from the end user to the data provider. We demonstrate our approach for both preprocessed SLC images and raw data using COSMO-SkyMed L1A and ALOS L0 products. The performance of our method depends on the quality of the digital elevation model (DEM) used—DEM error affects the correction phase proportionally to the baseline between radar scenes and the reference orbital path. With a 1000-m baseline and a nominal 30° incidence angle, we find that the uncertainty of estimated deformation increases by approximately 1 cm with every 3 m increase in the DEM error.

Restricted affine motion compensation and estimation in video coding with particle filtering and importance sampling: a multi-resolution approach

In this paper, we propose a multi-resolution affine block-based tracker for motion estimation and compensation, compatible with existing video coding standards such as H.264 and HEVC. We propose three modifications to traditional motion compensation techniques in video coding standards such as H.264 and HEVC. First, we replace traditional search methods with an efficient particle filtering-based method, which incorporates information from both spatial and temporal continuity. Second, we use a higher order linear model in place of the traditional translation motion model in these standards to efficiently represent complex motions such as rotation and zoom. Third, we propose a multi-resolution framework that enables efficient parameter estimation. Results of extensive experimentation show reduced residual energy and better Peak Signal-to-Noise Ratio (PSNR, hereafter) as compared to H.264/HEVC for instance, especially in regions of complex motion such as zooming and rotation.

Coronary MR angiography using image-based respiratory motion compensation with inline correction and fixed gating efficiency.

PurposeThe purpose of this study was to evaluate a new inline motion compensation approach called image‐based navigation with Constant Respiratory efficiency UsIng Single End‐expiratory threshold (iNAV‐CRUISE) for coronary MR angiography (CMRA).MethodsThe CRUISE gating technique was combined with iNAV motion correction and implemented inline for motion‐compensated CMRA on a 1.5 Tesla scanner. The approach was compared to conventional diaphragmatic navigator gating (dNAVG) in 10 healthy subjects. The CMRA images were compared for vessel sharpness and visual score of the right coronary artery (RCA), left anterior descending artery (LAD), left circumflex, and scan time.ResultsThe scan time was similar between the methods (dNAVG: 6:32 ± 1:09 vs. iNAV‐CRUISE: 6:58 ± 0:17, P = not significant). However, the vessel sharpness of the RCA (dNAVG: 60.2 ± 10.1 vs. iNAV‐CRUISE: 71.8 ± 8.9, P = 0.001) and LAD (dNAVG: 58.0 ± 8.0 vs. iNAV‐CRUISE: 67.4 ± 7.1, P = 0.008) were significantly improved using iNAV‐CRUISE. The visual score of the RCA was higher using iNAV‐CRUISE compared to dNAVG (dNAVG: 3,4,3 vs. iNAV‐CRUISE: 4,4,3, P < 0.01).ConclusionThe iNAV‐CRUISE approach out‐performs the conventional respiratory motion compensation technique in healthy subjects. Although scan time was comparable, the image quality was improved using iNAV‐CRUISE. Magn Reson Med 79:416–422, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

ISAR imaging of moving satellite based on GO–PO scattering model

An efficient algorithm is proposed for the radar cross-section (RCS) prediction of complex target with electronically large size, which is a combination of geometrical optics and physical optics (GO–PO) method. The method taking the multiple reflections into account is applied to the electromagnetic scattering analysis of a satellite model. Then RCS curves of entire satellite model and the model without antenna structure are figured out. Based on the simulated echoes, the traditional inverse synthetic aperture radar (ISAR) images are discussed. Moreover, an application of motion compensation technique based on the joint time-frequency analysis is presented for ISAR imaging of the moving satellite that has both translational and rotational movements. Numerical results show good performance of GO–PO method in accuracy and efficiency and the great influence of the antenna with corner structures on the scattering characteristic of the satellite.

Enhancing Cardiac PET by Motion Correction Techniques

Cardiac positron emission tomography (PET) images often contain errors due to cardiac, respiratory, and patient motion during relatively long image acquisition. Advanced motion compensation techniques may improve PET spatial resolution, eliminate potential artifacts, and ultimately improve the research and clinical capabilities of PET. Combined cardiac and respiratory gating has only recently been implemented in clinical PET systems. Considering that the gated image bins contain much lower counts than the original PET data, they need to be summed after correcting for motion, forming motion-corrected, high-count image volume. Furthermore, automated image registration techniques can be used to correct for motion between CT attenuation scan and PET acquisition. While motion correction methods are not yet widely used in clinical practice, approaches including dual-gated non-rigid motion correction and the incorporation of motion correction information into the reconstruction process have the potential to markedly improve cardiac PET imaging.

3D dosimetric validation of motion compensation concepts in radiotherapy using an anthropomorphic dynamic lung phantom

In this study, we developed a new setup for the validation of clinical workflows in adaptive radiation therapy, which combines a dynamic ex vivo porcine lung phantom and three-dimensional (3D) polymer gel dosimetry. The phantom consists of an artificial PMMA-thorax and contains a post mortem explanted porcine lung to which arbitrary breathing patterns can be applied. A lung tumor was simulated using the PAGAT (polyacrylamide gelatin gel fabricated at atmospheric conditions) dosimetry gel, which was evaluated in three dimensions by magnetic resonance imaging (MRI). To avoid bias by reaction with oxygen and other materials, the gel was collocated inside a BAREX™ container. For calibration purposes, the same containers with eight gel samples were irradiated with doses from 0 to 7 Gy. To test the technical feasibility of the system, a small spherical dose distribution located completely within the gel volume was planned. Dose delivery was performed under static and dynamic conditions of the phantom with and without motion compensation by beam gating. To verify clinical target definition and motion compensation concepts, the entire gel volume was homogeneously irradiated applying adequate margins in case of the static phantom and an additional internal target volume in case of dynamically operated phantom without and with gated beam delivery. MR-evaluation of the gel samples and comparison of the resulting 3D dose distribution with the planned dose distribution revealed a good agreement for the static phantom. In case of the dynamically operated phantom without motion compensation, agreement was very poor while additional application of motion compensation techniques restored the good agreement between measured and planned dose. From these experiments it was concluded that the set up with the dynamic and anthropomorphic lung phantom together with 3D-gel dosimetry provides a valuable and versatile tool for geometrical and dosimetrical validation of motion compensated treatment concepts in adaptive radiotherapy.

Novel Block Matching Reduced Complexity Motion Estimation and Compensation Algorithm for Mobile Domain: DBTSSDS

Communication between ends have dramatically increased by the expansion in wired (Hard) and wireless networks (soft wire). The user end machines have constrained capability. The availability of power/computation capability/storage and processing buffer/registers along with display. This necessitate the processing or preprocessing of information before transmitting in processed, compressed form. The bottleneck is to transmit the data through the channel with constrained capacity, in error free and acceptable quality. The data is enormously increases with HD content further necessitate effective and vigorous video processing procedures to permit error free real-time encoding and decoding. The real-time conferencing and events generates large sets of data which demands maximum level of compression and very high quality of reception. Even though latest standards like 3G /4G/5G along with efficient coding techniques the available channel has significantly increased but still processing is needed to adjust and accommodate more information in terms of numbers and quality. Numerous methodology had been proposed for compressing the Video but Block Matching methodology(BM) remains the most acceptable. BM is also commonly known as Motion Estimation and compensation(ME) techniques had been utilized for reducing the computational complication of the coding process. BM algorithms is important for accomplishing the effectual and reasonable compression. The block matching algorithm dictates the total computation cost and actual bit budget. Lately various fast search algorithms for video coding have also been proposed. This paper presents a method built on the extension and adjustment of research work MTSSDS block matching algorithm. The proposed algorithm utilizes the concept of logical dead blocks. The projected algorithm is labeled as DBTSSDS which expands to include and manipulate Dead Block on Modified Three steps and Diamond Search (DS) Block Matching Algorithm for the active block based motion estimation for mobile domain. It has been found that from the original (3SS/TSS) and DS, the PSNR value (thus quality) has increased slightly and the significant lowering of computations and thus computation time (faster) has been reduced significantly. The investigational fallouts utilizing various video sequences with different environment are utilized for validating and equate the benefits of projected motion estimation technique.

The effect of isoflurane on 18F-FDG uptake in the rat brain: a fully conscious dynamic PET study using motion compensation.

BackgroundIn preclinical positron emission tomography (PET) studies an anaesthetic is used to ensure that the animal does not move during the scan. However, anaesthesia may have confounding effects on the drug or tracer kinetics under study, and the nature of these effects is usually not known.MethodWe have implemented a protocol for tracking the rigid motion of the head of a fully conscious rat during a PET scan and performing a motion compensated list-mode reconstruction of the data. Using this technique we have conducted eight rat studies to investigate the effect of isoflurane on the uptake of 18F-FDG in the brain, by comparing conscious and unconscious scans.ResultsOur results indicate that isoflurane significantly decreases the whole brain uptake, as well as decreasing the relative regional FDG uptake in the cortex, diencephalon, and inferior colliculi, while increasing it in the vestibular nuclei. No statistically significant changes in FDG uptake were observed in the cerebellum and striata.ConclusionThe applied event-based motion compensation technique allowed for the investigation of the effect of isoflurane on FDG uptake in the rat brain using fully awake and unrestrained rats, scanned dynamically from the moment of injection. A significant effect of the anaesthesia was observed in various regions of the brain.

Utilizing Massive Compute Resources in the Public Cloud for Complex Image Processing

This paper explores the deployment of complex image processing applications in a public cloud to make massive processing jobs practical for post-production budgets and timescales. It uses an illustrative example of an iterative motion-compensated super-resolution pixel reconstruction technique deployed in a cloud platform that can process what was an 8-week job on local hardware in a few hours using a public cloud. However, the technique is not without its pitfalls. Even large public cloud data centers have practical limits that cannot be ignored. Real-world examples range from 35-mm restoration for digital 3D re-release to the latest Hollywood 120 frames/sec, 4K, 3D high-dynamic-range content. Large-scale resources can be leveraged for otherwise impractical techniques, opening the door to a new breed of high-end media processing tools and making them accessible to post-production facilities.