Background Ultrasonic tactile representation utilizes focused ultrasound to create tactile sensations on the bare skin of a user's hand that is not in contact with a device.This study is a preliminary investigatio...Background Ultrasonic tactile representation utilizes focused ultrasound to create tactile sensations on the bare skin of a user's hand that is not in contact with a device.This study is a preliminary investigation on whether different ultrasonic haptic rendering methods have an impact on the perceptual threshold.Methods This study conducted experiments with the adaptive step method to obtain participants'perceptual thresholds.We examine(1)whether different parts on the palm of the hand have different perceptual thresholds;(2)whether the perceptual threshold is different when the ultrasonic focus point is stationary and when it moves in different trajectories;(3)whether different moving speeds of the ultrasonic focus point have an influence on the perceptual threshold;and(4)whether the addition of a DC offset to the modulating wave has an impact on the perceptual threshold.Results The results show that the center of the palm is more sensitive to ultrasonic haptics than the fingertip;compared with a fast-moving focus point,the palm is more sensitive to a stationary and slow-moving focus point.When the modulating wave has a DC offset,the palm is sensitive to a much smaller modulation amplitude.Conclusion For the future ultrasonic tactile representation systems,dynamic adjustment of intensity is required to compensate the difference in perceptual thresholds under different rendering methods to achieve more realistic ultrasonic haptics.展开更多
Currently,the main idea of iterative rendering methods is to allocate a fixed number of samples to pixels that have not been fully rendered by calculating the completion rate.It is obvious that this strategy ignores t...Currently,the main idea of iterative rendering methods is to allocate a fixed number of samples to pixels that have not been fully rendered by calculating the completion rate.It is obvious that this strategy ignores the changes in pixel values during the previous rendering process,which may result in additional iterative operations.展开更多
The visual noise of each light intensity area is different when the image is drawn by Monte Carlo method.However,the existing denoising algorithms have limited denoising performance under complex lighting conditions a...The visual noise of each light intensity area is different when the image is drawn by Monte Carlo method.However,the existing denoising algorithms have limited denoising performance under complex lighting conditions and are easy to lose detailed information.So we propose a rendered image denoising method with filtering guided by lighting information.First,we design an image segmentation algorithm based on lighting information to segment the image into different illumination areas.Then,we establish the parameter prediction model guided by lighting information for filtering(PGLF)to predict the filtering parameters of different illumination areas.For different illumination areas,we use these filtering parameters to construct area filters,and the filters are guided by the lighting information to perform sub-area filtering.Finally,the filtering results are fused with auxiliary features to output denoised images for improving the overall denoising effect of the image.Under the physically based rendering tool(PBRT)scene and Tungsten dataset,the experimental results show that compared with other guided filtering denoising methods,our method improves the peak signal-to-noise ratio(PSNR)metrics by 4.2164 dB on average and the structural similarity index(SSIM)metrics by 7.8%on average.This shows that our method can better reduce the noise in complex lighting scenesand improvethe imagequality.展开更多
基金the National Key Research and Development Program(2016YFB1001304)and the National Natural Science Foundation of China(61631010).
文摘Background Ultrasonic tactile representation utilizes focused ultrasound to create tactile sensations on the bare skin of a user's hand that is not in contact with a device.This study is a preliminary investigation on whether different ultrasonic haptic rendering methods have an impact on the perceptual threshold.Methods This study conducted experiments with the adaptive step method to obtain participants'perceptual thresholds.We examine(1)whether different parts on the palm of the hand have different perceptual thresholds;(2)whether the perceptual threshold is different when the ultrasonic focus point is stationary and when it moves in different trajectories;(3)whether different moving speeds of the ultrasonic focus point have an influence on the perceptual threshold;and(4)whether the addition of a DC offset to the modulating wave has an impact on the perceptual threshold.Results The results show that the center of the palm is more sensitive to ultrasonic haptics than the fingertip;compared with a fast-moving focus point,the palm is more sensitive to a stationary and slow-moving focus point.When the modulating wave has a DC offset,the palm is sensitive to a much smaller modulation amplitude.Conclusion For the future ultrasonic tactile representation systems,dynamic adjustment of intensity is required to compensate the difference in perceptual thresholds under different rendering methods to achieve more realistic ultrasonic haptics.
基金supported partially by the National Natural Science Foundation of China(No.U19A2063)the Jilin Provincial Science&Technology Development Program of China(No.20230201080GX)。
文摘Currently,the main idea of iterative rendering methods is to allocate a fixed number of samples to pixels that have not been fully rendered by calculating the completion rate.It is obvious that this strategy ignores the changes in pixel values during the previous rendering process,which may result in additional iterative operations.
基金supported by the National Natural Science(No.U19A2063)the Jilin Provincial Development Program of Science and Technology (No.20230201080GX)the Jilin Province Education Department Scientific Research Project (No.JJKH20230851KJ)。
文摘The visual noise of each light intensity area is different when the image is drawn by Monte Carlo method.However,the existing denoising algorithms have limited denoising performance under complex lighting conditions and are easy to lose detailed information.So we propose a rendered image denoising method with filtering guided by lighting information.First,we design an image segmentation algorithm based on lighting information to segment the image into different illumination areas.Then,we establish the parameter prediction model guided by lighting information for filtering(PGLF)to predict the filtering parameters of different illumination areas.For different illumination areas,we use these filtering parameters to construct area filters,and the filters are guided by the lighting information to perform sub-area filtering.Finally,the filtering results are fused with auxiliary features to output denoised images for improving the overall denoising effect of the image.Under the physically based rendering tool(PBRT)scene and Tungsten dataset,the experimental results show that compared with other guided filtering denoising methods,our method improves the peak signal-to-noise ratio(PSNR)metrics by 4.2164 dB on average and the structural similarity index(SSIM)metrics by 7.8%on average.This shows that our method can better reduce the noise in complex lighting scenesand improvethe imagequality.
