Influence of a reduced wearing time on the attenuation of hearing protectors assessed via temporary threshold shifts

Valuable recommendations for the choice, utilization, care, and maintenance, and for the measurement of sound attenuation of hearing-protective devices have been laid down in international standards. Yet, by considering the wearing time of a hearing protector, the standard DIN EN 458 assumes a scarcely understandable drastic reduction in the effective attenuation even when the device is not used for only a short time in a noise-filled area. A 30 dB sound attenuation of such a protective device would, e.g., decrease to 12 dB if it were unused for only 30 min of an 8 h shift. Thus, the actual influence of a shortened wearing time on the protection of earmuffs was tested in a laboratory study using audiometric measurements of the temporary threshold shift (TTS₂) and its recovery after exposure to noise. For that purpose, the effectiveness of a hearing-protective device depending on the amount of time worn as prognosticated by DIN EN 458 was compared with the actual physiological effect of the earmuffs. Ten test subjects (Ss) participated in three test series (TS), each. In the first of the TS, the Ss were exposed to a sound pressure of 106 dB(A) for 1 h, during which the Ss wore noise-insulating earmuffs with an attenuation of 30 dB. The Ss were exposed to the same sound pressure in TS II; however, after 30 min, the earmuffs were removed for a duration of  min. Mathematically, this reduced the sound attenuation of the earmuffs to 12 dB, i.e., the average noise level over 1 h is 94 dB, which is equivalent to 85 dB(A) over 8 h. In order to evaluate the actual additional physiological cost of TS II, the Ss were exposed to 94 dB(A)/1 h without earmuffs in a third TS. This acoustic load, which is energy equivalent to the load in TS II, is also equivalent to 85 dB(A)/8 h. The results show that the continuous wearing of the earmuffs offers secure protection. However, the energetic approach and the levelling of differently structured noise loads according to the principle of energy equivalence leads to misconceiving results. The drastic reduction of the sound attenuation of the earmuffs predicted from the energetic point of view must be regarded as exaggerated. The TTS values show that TS II – which, according to the principle of energy-damage-equivalence, should result in the same effects as TS III – represents significantly less auditory fatigue. Thus, if the earmuffs are taken off briefly, a drastic reduction in the protection – as predicted in DIN EN 458 — does not result.

Relevance to industry

The results of this study demonstrate that the standards and regulations for noise rating do not correspond with the actual physiological facts and, therefore, can only be used in a very limited manner. Utilization of the principle of energy equivalence has proven problematic not only for rating noise. This principle also leads to an essential underestimation of the attenuation of hearing protectors when these devices are taken off for only a short time in a noise-filled area.     

基于L1和L2混合范式的序列图像超分辨率重建

针对超分辨率重建时需要同时滤除高斯噪声和脉冲噪声的问题,提出一种基于L₁和L₂混合范式并结合双边全变分(BTV)正则化的序列图像超分辨率重建方法。首先基于多分辨率策略的光流场模型对序列低分辨率图像进行配准,使图像的配准精度达到亚像素级,进而可以利用图像间的互补信息提高图像分辨率;其次利用L₁和L₂混合范式的优点,用BTV正则化算法解决重建的病态性反问题;最后进行序列图像超分辨率重建。实验数据显示算法可以降低图像均方误差,并将峰值信噪比(PSNR)提高1.2 dB~5.2 dB。实验结果表明,提出的算法能够有效地滤除高斯和脉冲噪声,保持图像边缘,提高图像可辨识度,可为车牌识别、人脸识别和视频监控等方面提供了良好的技术基础。     

Assessment of potential noise-induced hearing loss with commercial “Karaoke” noise

A study was conducted to assess the noise levels of popular Karaoke environments in Korea and the degree of potential noise-induced hearing loss due to commercial Karaoke noise. Using 18 subjects with normal hearing, a two-way, mixed-factors experimental design was used with two independent variables of “noise source” (no-singer, one-singer, and two-singer conditions) and “music type” (Trot, Ballad, and Rock music). For each experimental condition, average sound pressure levels and maximum sound pressure levels were measured. For assessing amount of temporary hearing threshold shift as a measure of potential hearing loss index, pure-tone audiometry was applied for measuring subjects’ hearing threshold levels of both ears before and after 100 min exposure to Karaoke noise. Questionnaires from 155 actual Karaoke users were also obtained to evaluate realistic user subjective perception on the Karaoke environment. Results showed that noise levels of typical Karaoke singing environments were higher than 95 dBA, with maximum noise levels often exceeded the US OSHA's non-permissible 115 dBA level. Further statistical analysis of hearing threshold shift revealed that up to 8 dB of significant hearing loss was found at the most important human hearing frequency band, centered at 4000 Hz, after about less than 2 h of Karaoke noise exposure, indicating that Karaoke facilities may pose a serious threat to noise-induced hearing loss. Along with some ergonomic/safety issues, practical hearing protection strategies are suggested and discussed.

Relevance to industry

Since noise levels from popular commercial Karaoke facilities are found to be potentially dangerous, the Karaoke-related industries, of supporting a big consumer market of entertainment, need to provide safer environments to protect naive users from potential hearing loss. Providing better design of Karaoke facilities with some ergonomic intervention strategies (such as proper sound absorptive treatment in Karaoke rooms, displaying warning signs of potential hearing loss, and setting up an upper safety volume limit in the Karaoke machine, etc.) may help those industries not only contribute for consumer protection but also develop better market with strong ethical and legal support in the future.     

Frequency weighting for the evaluation of steering wheel rotational vibration

The human perception of rotational hand–arm vibration has been investigated by means of a test rig consisting of a rigid frame, an electrodynamic shaker unit, a rigid steering wheel, a shaft assembly, bearings and an automobile seat. Fifteen subjects were tested while seated in a driving posture. Four equal sensation tests and one annoyance threshold test were performed using sinusoidal excitation at 18 frequencies in the range from 3 to 315 Hz. In order to guarantee the generality of the equal sensation data, the four tests were defined to permit checks of the possible influence of three factors: reference signal amplitude, psychophysical test procedure and temporary threshold shift caused by the test exposure. All equal sensation tests used a reference sinusoid of 63 Hz at either 1.0 or 1.5 m/s² r.m.s. in amplitude. The four equal sensation curves were similar in shape and suggested a decrease in human sensitivity to hand–arm rotational vibration with increasing frequency. The slopes of the equal sensation curves changed at transition points of approximately 6.3 and 63 Hz. A frequency weighting, called W_s, was developed for the purpose of evaluating steering wheel rotational vibration. The proposed W_s has a slope of 0 dB per octave over the frequency range from 3 to 6.3 Hz, a slope of −6 dB per octave from 6.3 to 50 Hz, a slope of 0 dB per octave from 50 to 160 Hz and a slope of −10 dB per octave from 160 to 315 Hz. W_s provides a possible alternative to the existing W_h frequency weighting defined in International Standards Organisation 5349-1 (2001) and British Standards Institution BS 6842 (1987).

Relevance to industry

For the manufacturers of tyres, steering systems and other vehicular components the proposed W_s frequency weighting provides a more accurate representation of human perception of steering wheel rotational vibration than the W_h weighting of ISO 5349-1 and BS6842.     

Physiological costs of the hearing due to noise exposure,additional physical stress,and combined exposure to alcohol and cigarette smoke

In 2 studies, each with 5 test series, physiological costs of the hearing due to legally tolerable noise exposures of 94 dB (A) for 1 hr have been measured audiometrically. The temporary threshold shifts (TTS) and their restitution time, as well as cardiovascular responses in work‐related heart rate increases, of 10 and 8 subjects (Ss), respectively, could be shown to be modulated by additional physical stress and combined exposure to alcohol (Study 1) and cigarette smoke (Study 2). Moderate dynamic muscle work (50 W) administered via a bicycle ergometer either immediately after noise, or simultaneous to the noise exposure, significantly reduced restitution time as well as the integrated restitution temporary threshold shift (IRTTS). A physical stress to 100 W—which exceeded the endurance level when demanded simultaneously to the noise exposure—did not show any favorable effects. However, if the same physical stress succeeded the noise exposure, and when it was interrupted several times for the audiometric measurements, it also brought about significant accelerations of the restitution processes. Some reductions in physiological costs of the hearing were found due to an intervening alcohol consumption (blood alcohol concentration ～ 0.08%) prior to the noise exposure and a simultaneous physical load of 50 W. Smoking 10 cigarettes instead of the consumption of alcohol was associated with a reduced TTS, but a prolonged restitution time. IRTTS as total physiological costs of the most unfavorable combination of noise, simultaneous high physical workload, and preceding smoke exposure was increased. The results of the test series with cigarette smoke—probably due to the small group of just 8 Ss and the counteracting effects of the agents carbon monoxide (CO) and nicotine—were not statistically significant, but these exposures were associated with a substantial activation of the cardiovascular system. Significant heart rate increases are evidence that CO and nicotine must not be neglected as influential factors in the context of physiological costs that the organism, and especially the hearing, has to pay for noise exposures. © 2002 Wiley Periodicals, Inc.     

Silicon condenser microphones with corrugated silicon oxide/nitride electret membranes

Corrugated electret membranes are used in a micromachined silicon microphone. The membranes consist of a permanently corona-charged double layer of silicon dioxide and silicon nitride, known to have excellent charge-storing properties. This electret can replace the external bias needed for condenser microphones. The well-known LOCOS technique—also combined with dry etching—is used for the first time to fabricate membranes with corrugation depths of several microns. The membrane thickness amounts to 600 nm.

The interferometrically measured center deflection is up to 40 nm/Pa for diaphragms with four corrugations of up to 3.3 μm depth and a size of A_M=1 mm². This high mechanical sensitivity limits the dynamic range to sound pressures below 50 Pa. The obtained mechanical sensitivities are in excellent agreement with the theory.

The most compliant corrugated diaphragms result in a microphone sensitivity of 2.9 mV/Pa, an equivalent noise level of 39 dB(A) and a total harmonic distortion below 1.7% at 28 Pa (123 dB SPL). The corrugation depth in the sensors has been only 1.3 μm. All sensors cover the whole audio and low ultrasonic range. The temperature coefficient is between 0.05 and 0.1 dB/K.     

电力线通信系统中基于OFDM/OQAM的时频结合消噪算法

针对电力线通信（PLC）系统中存在严重影响传输性能的脉冲噪声,传统的消噪算法大都不能有效抑制脉冲噪声的问题,提出一种时频结合的消噪算法。首先,通过选择合适的门限对时域接收信号中峰值较大的脉冲噪声进行检测和置零处理;然后,在频域根据已判决的符号来重构时域尚未消除完的峰值较小的脉冲噪声,并通过迭代来提高噪声重构的准确性;最后,从频域接收信号中减去重构的脉冲噪声。在电力线多径信道下进行仿真实验,相比传统的时域消噪和频域消噪算法,所提算法在误比特率为0.01时可以分别实现2 dB和0.5 dB的性能提升,而随着误比特率的降低,它们之间的性能差距将会更大。仿真结果表明,所提出的时频结合消噪算法能够提高电力线通信系统对脉冲噪声的抵抗能力。     

自适应加权编码L1/2正则化的图像重建算法

针对图像重建过程中噪声去除问题,提出一种自适应加权编码L_1/2正则化重建算法。首先,考虑到许多真实图像中不仅含有高斯噪声,而且含有拉普拉斯噪声,设计一种改进的L₁-L₂混合误差模型(IHEM)算法,该算法兼顾了L₁范数与L₂范数的各自优点;其次,由于迭代过程中噪声分布会发生改变,设计一种自适应隶属度算法,该算法可以减少迭代次数和运算时间;利用一种自适应加权编码方法,该方法可以有效地去除含有重尾分布特性的拉普拉斯噪声;另外,设计一种L_1/2正则化算法,该算法可以得到较稀疏的解。实验结果表明,相比IHEM算法,自适应L_1/2正则化图像重建算法的峰值信噪比(PSNR)平均提高了3.46 dB,结构相似度(SSIM)平均提高了0.02,对含有多种噪声的图像处理具有比较理想的效果。     

Development of an optical hydrogen sulphide sensor

A hydrogen sulphide (H₂S)-sensitive optode film has been fabricated by immobilising tetraoctylammonium fluorescein mercury(II) acetate (TOFMA) and tri-n-butyl phosphate in a poly(vinyl chloride) (PVC) matrix. The optode film, coated on an overhead transparency film, was employed as a sensing device for fluorimetric detection of H₂S. The fluorescence intensity monitored at 553 nm (excitation at 503 nm) increased with increasing H₂S concentrations. The optode film showed a good, linear and reversible response to H₂S from 0 to 15 ppm (v/v). It was optically stable and the reproducible response of the film on exposure to 10 ppm (v/v) H₂S was extremely good. There was no sign of degradation after 8 h of continuous use. The response to H₂S levelled off at about 27.5 ppm The response and recovery times of the optical H₂S sensor were fast and less than 2 and 5 s, respectively. An optically-based sensor for H₂S determination was successfully developed. It was anticipated that the system could be used to monitor H₂S with a concentration range of 0–25 ppm (v/v) with satisfactory results. A proposed mechanism for the detection of H₂S by the optode films is described.     

Noise exposed of the operators of combine harvesters with and without a cab

A considerable number of the combine harvesters in Turkey are rather old and used without cabs resulting in unhealthy working conditions for their operators. Noise is one of the detrimental factors. This study deals with determining and comparing the noise exposed on the operators of the combines with and without a cab used for wheat harvesting in Turkey. The sound pressure levels (dB) at octave band center frequencies (31.5–8000 Hz) and the sound levels (dBA) at the ear level of the operators were measured on 37 different combine harvesters with four different makes and different years from 1976 to 2001. Fifteen of the combines were without a cab, another 15 had original cabs while remaining seven combines had cabs mounted on them after manufacturing.

The sound pressure levels were in a decreasing trend from the lower frequencies to higher frequencies. This trend was more noticeable for the combines with original cab and with the cab mounted after manufacturing compared to the ones without cab. The use of a cab was more effective in the insulation of the noise at the medium and higher frequencies, which have more bothersome effect compared to the lower frequencies. The sound pressure levels were 75–102 dB and 46–89 dB at low (31.5–500 Hz) and high (500–8000 Hz) frequencies for all combines, respectively. The sound pressure levels at the frequency of 4000 Hz at which the human ear is most sensitive were 6–17 dB lower for the combines with the cabs mounted after manufacturing and 9–28 dB lower for the ones with the original cabs compared to the combines without cab. The sound levels were 85–90, 81–83, and 76–81 dBA for the combines without cab, with cab mounted after manufacturing, and with original cab, respectively.

The study showed that the use of a cab was useful in the insulation of the noise, particularly at higher frequencies. In addition, it protects the operator from the factors having detrimental effects on the working efficiency such as high temperature and dusty environment. The authors strongly recommend mounting of a cab on to the combines currently being used without a cab in rental system in Turkey to provide healthy working conditions for their operators.     

Random Early Detection method for ABR service

A new implementation for the Random Early Detection method algorithm for ABR (REDM–ABR) service is proposed in this paper. It keeps running an exponential average of the queue length (Q). When a cell arrives, the average queue size (Q_avg) is compared with two threshold levels, lower queue threshold (Q_L) and higher queue threshold (Q_H). If it is smaller than Q_L, the cell is passed, but if it is larger than Q_H, the cell marking probability is set to one. If it is in between the two thresholds, the cell marking probability is calculated depending on the value of Q_avg. The values of Resource Management (RM) cell fields: Congestion Indication (CI), No Additive Increase (NI), and Explicit Rate (ER) are filled by the Relative Rate Marking (RRM) switch and sent back to the sources. The sources will change their rate depending on CI, NI, and ER values. To investigate the effect of decreasing the impending congestion area, a dynamic Q threshold (Q_D) is used. The Q_D is shifted from Q_L toward Q_H for decreasing the congestion area and to investigate the effect of this shift on the performance of the switch through simulation study.     

Decentralized Resilient H∞ Load Frequency Control for Cyber-Physical Power Systems Under DoS Attacks

This paper designs a decentralized resilient H_∞ load frequency control (LFC) scheme for multi-area cyber-physical power systems (CPPSs). Under the network-based control framework, the sampled measurements are transmitted through the communication networks, which may be attacked by energy-limited denial-of-service (DoS) attacks with a characterization of the maximum count of continuous data losses (resilience index). Each area is controlled in a decentralized mode, and the impacts on one area from other areas via their interconnections are regarded as the additional load disturbance of this area. Then, the closed-loop LFC system of each area under DoS attacks is modeled as an aperiodic sampled-data control system with external disturbances. Under this modeling, a decentralized resilient H_∞ scheme is presented to design the state-feedback controllers with guaranteed H_∞ performance and resilience index based on a novel transmission interval-dependent loop functional method. When given the controllers, the proposed scheme can obtain a less conservative H_∞ performance and resilience index that the LFC system can tolerate. The effectiveness of the proposed LFC scheme is evaluated on a one-area CPPS and two three-area CPPSs under DoS attacks.      

The intensity of auditory warning tones in the automobile environment: detection and preference evaluations

A variety of auditory warning tones was evaluated to determine generally appropriate intensity levels for presentation in the automobile environment. Twenty-four subjects listened to tones presented at several intensity levels under three background noise conditions recorded in actual vehicles: relatively quiet (35 mile/h (56 km/h), smooth road), relatively loud (55 mile/h (89 km/h), rough road), and radio (35 mile/h (56 km/h), smooth road, and radio broadcast). Data were gathered on the minimum intensity level (in decibels (dB) above the masked threshold (MT) required to achieve a consistent criterion detection rate, as well as the preferred tone intensity level (in dB above the MT) in each background noise condition. The preferred levels were louder than those required to achieve the detection criterion in both the relatively loud and quiet background noise conditions; thus, the preferred levels are the recommended levels under those conditions. This was not the case in the radio condition; therefore, it is recommended that future research efforts evaluate the effects of automatically muting the radio/stereo system when important auditory warning tones are being presented.     

Characterization of transition metal oxide ceramic material for continuous thermocouple and its use as NTC fire wire sensor

The ceramic powder prepared from the mixture of Mn₃O₄ and La₂O₃ have been characterized for NTC behavior and the same have been used as CT²C (continuous thermocouple) sensor in the form of a thin metal cable to detect over-heating. These materials have mega ohm resistance at room temperature and showed exponential drop in resistance with the rise in temperature over a temperature range of 100–400 °C. It has been observed that as the concentration of La₂O₃ increases from 0 to 10% the NTC behavior drops from (400–260 °C) ±10%. The material was pressed into pellets and sintered at 700 °C for 3 h resulting in good bonding strength. Electrical characterization of the material was done by measuring the resistance over a temperature range of 100–400 °C. The material showed reproducible NTC characteristics over the temperature range 400, 370, 340, 280, and 260 °C with decreasing thermistor constant values (B = 9588, 9210, 8500, 5170, 3330 K⁻¹) and activation energy (ΔE = 826, 794, 733, 445, 287 meV), respectively. The decrease in activation energy of the ceramic powder with increase in La₂O₃ concentration makes it possible to fabricate thermal sensors which can be used in different temperature ranges. The microstructure was studied using SEM and evidence of a sintered body with grain size around 1 μm was observed in the material. XRD analysis indicated the single-phase tetragonal structure of the ceramic material. The process of using this ceramic material for fabrication of 10 ft continuous fire wire sensor has been explained.     

Robust Fault Detection and Isolation Based on Finite-frequency H?/H∞ Unknown Input Observers and Zonotopic Threshold Analysis

This work proposes a robust fault detection and isolation scheme for discrete-time systems subject to actuator faults, in which a bank of H_?/H_∞ fault detection unknown input observers (UIOs) and a zonotopic threshold analysis strategy are considered. In observer design, finite-frequency H_? index based on the generalized Kalman-Yakubovich-Popov lemma and H_∞ technique are utilized to evaluate worst-case fault sensitivity and disturbance attenuation performance, respectively. The proposed H_?/H_∞ fault detection observers are designed to be insensitive to the corresponding actuator fault only, but sensitive to others. Then, to overcome the weakness of predefining threshold for FDI decision-making, this work proposes a zonotopic threshold analysis method to evaluate the generated residuals. The FDI decision-making relies on the evaluation with a dynamical zonotopic threshold. Finally, numerical simulations are provided to show the feasibility of the proposed scheme.      

On exact filters for continuous signals with discrete observations

Many filtering applications have continuous state dynamics X_t =∫₀^tm(X_s)ds+σW_t +ρ, discrete observations Y_j=Y(t_j), and nonadditive or non-Gaussian observation noise. One wants to calculate the conditional probability Pr{Xt∈dz|Y_j, 0⩽t_j ⩽t} economically. In this paper we show that a combination of convolution, scaling, and substitutions efficiently solves this problem under certain conditions. Our method is easy to use and assumes nothing about the observations other than the ability to construct p(Y_j )|X(t_j), the conditional density of the jth observation given the current state     

Robust integrated shift register circuit over clock noises for in‐cell touch applications

This paper proposes an integrated shift register circuit for an in‐cell touch panel that is robust over clock noises. It is composed of 10 thin film transistors and 1 capacitor, and the time division driving method is adopted to prevent the negative effect of display signals on the touch sensing. Two pre‐charging nodes are employed for reducing the uniformity degradation of gate pulses over time. In particular, the proposed circuit connects a drain of the first pre‐charging node's pull‐up thin film transistor (TFT) to the positive supply voltage instead of clock signals. This facilitates to lower coupling noises as well as to clock power consumption. The simulation program with an integrated circuit emphasis is conducted for the proposed circuit with low temperature poly‐silicon TFTs. The positive threshold voltage that shifts up to 12 V at the first pre‐charging pull‐up TFT can be compensated for without the uniformity degradation of gate pulses. For a 60‐Hz full‐HD display with a 120‐Hz reporting rate of touches, the clock power consumption of the proposed gate driver circuit is estimated as 7.13 mW with 160 stages of shift registers. In addition, the noise level at the first pre‐charging node is lowered to ?28.95 dB compared with 2.37 dB of the previous circuit.     

A comparative study of the physical properties of CdS, Bi2S3 and composite CdS–Bi2S3 thin films for photosensor application

Thin films of CdS, Bi₂S₃ and composite CdS–Bi₂S₃ have been deposited using modified chemical bath deposition (M-CBD) technique. The various preparative parameters were optimized to obtain good quality thin films. The as-deposited films of CdS, Bi₂S₃ and composite were annealed in Ar gas at 573 K for 1 h. A comparative study was made for as-deposited and annealed CdS, Bi₂S₃ and composite thin films. Annealing showed no change in crystal structure of these as-deposited films. However, an enhancement in grain size was observed by AFM studies. In addition change in band gap with annealing was seen. A study of spectral response, photosensitivity showed that the films can be used as a photosensor.     

Comparative assessment of shift in hearing threshold among handicraft operatives in India

This case-control exploratory study is first of its kind to assess the noise exposure and loss in hearing threshold (HT) due to the occupational use of hand tools used for handicraft work. Sixty male participants involved in different crafts trade and a reference group of 50 office workers were selected. The sound pressure levels under actual work conditions were measured as per the method outlined in IS 7194:1994. The mean equivalent sound pressure level was quite high (96.37?dB(A)), exceeding the exposure limit of 90?dB(A). Audiometric tests were conducted to compare the HT between both the groups. In agreement with dose consumed, the exposed workers exhibit moderate hearing impairment in the frequency range of 1500–6000?Hz. The association of HT at different frequencies among occupation were detected using post-hoc multiple comparisons. 95% of the workers showed hearing handicap at some level and noise-induced hearing loss increases with higher age and experience. Interventions in the hand tools, implementation of hearing conservation programmes and practice of personal protective equipments have been suggested.

Practitioner Summary: As the primary outcomes, comparative assessment of the shift in hearing threshold was analyzed in anticipation to develop a better work system. Results from the study report that the sound pressure level was fairly high and 95% of the handicraft operatives showed hearing handicap at some level.     

基于非凸全变差正则的核磁共振图像重构算法

针对于核磁共振（MR）图像重构中由于欠采样导致的重构图像不够完整、边缘模糊以及噪声残留等问题,提出了一种基于L₂正则的非凸全变差正则重构模型。首先,以Moreau包络和最小最大凹罚函数为工具构造L₂范数的非凸正则;然后,将其应用于全变差正则上来构造各向同性的非凸全变差正则稀疏重构模型。所提的非凸正则可以有效地避免凸正则中对较大非零元欠估计现象,能够更有效地重构目标的边缘轮廓;同时,在一定条件下可以保证目标函数的整体凸性,从而最后可以利用交替方向乘子法（ADMM）对模型进行求解。仿真实验对若干MR图像在不同的采样模板和采样率下进行了重构。实验结果均表明,与几种典型的图像重构方法相比,所提模型性能更优,相对误差明显降低,峰值信噪比（PSNR）有明显改善,较经典的L₁非凸正则重构模型提升了大约4 dB,并且重构后的图像视觉效果显著提升,有效地保留了原始图像的边缘细节。