Stretchable displays can withstand greater deformation than traditional displays,enabling their versatile integration into various electronic devices.However,when conventional stretchable displays are stretched,pixel ...Stretchable displays can withstand greater deformation than traditional displays,enabling their versatile integration into various electronic devices.However,when conventional stretchable displays are stretched,pixel size or spacing increases,reducing image quality.Various methods have been tried to maintain resolution,but the fill factor decreases when all pixels are active during stretching.Here,integrated stretchable OLEDs are presented with an integrated pixel density by overlapping quadrant pixels in voids.Overlapped pixels are vertically aligned to optically function as a single pixel in the original state.Upon stretching,these pixels are spatially separated and become individually visible,thereby increasing the fill factor.A reliable multilayered structure is designed through the patterned adhesive and the deposition of patterned electrodes.The PM-integrated stretchable display,consisting of a 3×2 array with one central pixel and four quadrant pixels per unit,successfully displayed various letters clearly in both the original and stretched states.展开更多
In recent days,detecting Optic Disc(OD)in retinal images has been challenging and very important to the early diagnosis of eye diseases.The process of detecting the OD is challenging due to the diversity of color,inte...In recent days,detecting Optic Disc(OD)in retinal images has been challenging and very important to the early diagnosis of eye diseases.The process of detecting the OD is challenging due to the diversity of color,intensity,brightness and shape of the OD.Moreover,the color similarities of the neighboring organs of the OD create difficulties during OD detection.In the proposed Fuzzy K‒Means Threshold(FKMT)and Morphological Operation with Pixel Density Feature(MOPDF),the input retinal images are coarsely segmented by fuzzy K‒means clustering and thresholding,in which the OD is classified from its neighboring organs with intensity similarities.Then,the segmented images are given as the input to morphological operation with pixel density feature calculations,which reduce the false detection in the small pixel of the OD.Finally,the OD area is detected by applying the Sobel edge detection method,which accurately detects the OD from the retinal images.After detection optimization,the proposed method achieved Sensitivity(SEN),Specificity(SPEC)and Accuracy(ACC),with 96.74%,96.78%and 96.92%in DiaretDB0(Standard Diabetic Retinopathy Database Calibration level 0),97.12%,97.10%and 97.75%in DiaretDB1(Standard Diabetic Retinopathy Database Calibration level 1)and 97.19%,97.47%and 97.43%in STARE(Structured Analysis of the Retina)dataset respectively.The experimental results demonstrated the proposed method’s efficiency for segmenting and detecting OD areas.展开更多
Developing a watermarking method that is robust to cropping attack is a challenging task in image watermarking. The moment-based watermarking schemes show good robustness to common signal processing attacks and some g...Developing a watermarking method that is robust to cropping attack is a challenging task in image watermarking. The moment-based watermarking schemes show good robustness to common signal processing attacks and some geometric attacks but are sensitive to cropping attack. In this paper, we modify the moment-based approach to deal with cropping attack. Firstly, we find the probability density function （PDF） of the pixel value distribution from the original image. Secondly, we reshape and normalize the pdf of the pixel value distribution （PPVD） to form a two dimensional image. Then, the moment invariants are calculated from the PPVD image. Since PPVD is insensitive to cropping, the proposed method is robust to cropping attack. Besides, it also has high robustness against other common attacks. Theoretical analysis and experimental results demonstrate the effectiveness of the proposed method.展开更多
基金supported by the Technology Innovation Program(20017569,Development of substrate materials thatcan be stretched more than 50%for stretchable displays)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)supported by the National R&D Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(2021M3C1C3097646)supported by BK21 FOUR(Connected AI Education&Research Program for Industry and Society Innovation,KAIST EE,No.4120200113769)。
文摘Stretchable displays can withstand greater deformation than traditional displays,enabling their versatile integration into various electronic devices.However,when conventional stretchable displays are stretched,pixel size or spacing increases,reducing image quality.Various methods have been tried to maintain resolution,but the fill factor decreases when all pixels are active during stretching.Here,integrated stretchable OLEDs are presented with an integrated pixel density by overlapping quadrant pixels in voids.Overlapped pixels are vertically aligned to optically function as a single pixel in the original state.Upon stretching,these pixels are spatially separated and become individually visible,thereby increasing the fill factor.A reliable multilayered structure is designed through the patterned adhesive and the deposition of patterned electrodes.The PM-integrated stretchable display,consisting of a 3×2 array with one central pixel and four quadrant pixels per unit,successfully displayed various letters clearly in both the original and stretched states.
文摘In recent days,detecting Optic Disc(OD)in retinal images has been challenging and very important to the early diagnosis of eye diseases.The process of detecting the OD is challenging due to the diversity of color,intensity,brightness and shape of the OD.Moreover,the color similarities of the neighboring organs of the OD create difficulties during OD detection.In the proposed Fuzzy K‒Means Threshold(FKMT)and Morphological Operation with Pixel Density Feature(MOPDF),the input retinal images are coarsely segmented by fuzzy K‒means clustering and thresholding,in which the OD is classified from its neighboring organs with intensity similarities.Then,the segmented images are given as the input to morphological operation with pixel density feature calculations,which reduce the false detection in the small pixel of the OD.Finally,the OD area is detected by applying the Sobel edge detection method,which accurately detects the OD from the retinal images.After detection optimization,the proposed method achieved Sensitivity(SEN),Specificity(SPEC)and Accuracy(ACC),with 96.74%,96.78%and 96.92%in DiaretDB0(Standard Diabetic Retinopathy Database Calibration level 0),97.12%,97.10%and 97.75%in DiaretDB1(Standard Diabetic Retinopathy Database Calibration level 1)and 97.19%,97.47%and 97.43%in STARE(Structured Analysis of the Retina)dataset respectively.The experimental results demonstrated the proposed method’s efficiency for segmenting and detecting OD areas.
基金partially funded by the Australian Research Council(No.DP110102076)
文摘Developing a watermarking method that is robust to cropping attack is a challenging task in image watermarking. The moment-based watermarking schemes show good robustness to common signal processing attacks and some geometric attacks but are sensitive to cropping attack. In this paper, we modify the moment-based approach to deal with cropping attack. Firstly, we find the probability density function （PDF） of the pixel value distribution from the original image. Secondly, we reshape and normalize the pdf of the pixel value distribution （PPVD） to form a two dimensional image. Then, the moment invariants are calculated from the PPVD image. Since PPVD is insensitive to cropping, the proposed method is robust to cropping attack. Besides, it also has high robustness against other common attacks. Theoretical analysis and experimental results demonstrate the effectiveness of the proposed method.
