Automatic Method for Contrast Enhancement of Natural Color Images

Shyam Lal,A. V. Narasimhadhan,Rahul Kumar 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

The contrast enhancement is great challenge in the image processing when images are suffering from poor contrast problem. Therefore, in order to overcome this problem an automatic method is proposed for contrast enhancement of natural color images. The proposed method consist of two stages: in first stage lightness component in YIQ color space is normalized by sigmoid function after the adaptive histogram equalization is applied on Y component and in second stage automatic color contrast enhancement algorithm is applied on output of the first stage. The proposed algorithm is tested on different NASA color images, hyperspectral color images and other types of natural color images. The performance of proposed algorithm is evaluated and compared with the other existing contrast enhancement algorithms in terms of colorfulness metric and color enhancement factor. The higher values of colorfulness metric and color enhancement factor imply that the visual quality of the enhanced image is good. Simulation results demonstrate that proposed algorithm provides higher values of colorfulness metric and color enhancement factor as compared to other existing contrast enhancement algorithms. The proposed algorithm also provides better visual enhancement results as compared with the other existing contrast enhancement algorithms.

Automatic Method for Contrast Enhancement of Natural Color Images

Lal, Shyam,Narasimhadhan, A. V.,Kumar, Rahul The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

The contrast enhancement is great challenge in the image processing when images are suffering from poor contrast problem. Therefore, in order to overcome this problem an automatic method is proposed for contrast enhancement of natural color images. The proposed method consist of two stages: in first stage lightness component in YIQ color space is normalized by sigmoid function after the adaptive histogram equalization is applied on Y component and in second stage automatic color contrast enhancement algorithm is applied on output of the first stage. The proposed algorithm is tested on different NASA color images, hyperspectral color images and other types of natural color images. The performance of proposed algorithm is evaluated and compared with the other existing contrast enhancement algorithms in terms of colorfulness metric and color enhancement factor. The higher values of colorfulness metric and color enhancement factor imply that the visual quality of the enhanced image is good. Simulation results demonstrate that proposed algorithm provides higher values of colorfulness metric and color enhancement factor as compared to other existing contrast enhancement algorithms. The proposed algorithm also provides better visual enhancement results as compared with the other existing contrast enhancement algorithms.

SOME τ-EXTENSIONS OF LAURICELLA FUNCTIONS OF SEVERAL VARIABLES

KALLA, SHYAM LAL,PARMAR, RAKESH KUMAR,PUROHIT, SUNIL DUTT Korean Mathematical Society 2015 대한수학회논문집 Vol.30 No.3

Motivated mainly by certain interesting extensions of the ${\tau}$-hypergeometric function defined by Virchenko et al. [11] and some ${\tau}$-Appell's function introduced by Al-Shammery and Kalla [1], we introduce here the ${\tau}$-Lauricella functions $F_A^{(n),{\tau}_1,{\cdots},{\tau}_n}$, $F_B^{(n),{\tau}_1,{\cdots},{\tau}_n}$ and $F_D^{(n),{\tau}_1,{\cdots},{\tau}_n}$ and the confluent forms ${\Phi}_2^{(n),{\tau}_1,{\cdots},{\tau}_n}$ and ${\Phi}_D^{(n),{\tau}_1,{\cdots},{\tau}_n}$ of n variables. We then systematically investigate their various integral representations of each of these ${\tau}$-Lauricella functions including their generating functions. Various (known or new) special cases and consequences of the results presented here are also considered.

Relative Wavelet Energy and Wavelet Entropy Based Epileptic Brain Signals Classification

Yatindra Kumar,Mohan Lal Dewal,Radhey Shyam Anand 대한의용생체공학회 2012 Biomedical Engineering Letters (BMEL) Vol.2 No.3

Purpose Manual analysis of EEG signals by an expert is very much time consuming due to the long length of EEG recordings. The suitable computerized analysis is essentially required to differentiate among the normal, interictal and ictal (epileptic) EEGs. Methods In the present work the EEG signals are decomposed into different sub-bands using discrete wavelet transform (DWT) to obtain the detail and the approximation wavelet coefficients. The coefficients are used to calculate the quantitative values of relative wavelet energy and wavelet entropy from different data sets to select the features of EEG signals. The support vector machine (SVM), feed forward back- propagation neural network (FFBPNN), k-Nearest Neighbor Classifier (k-NN) and Decision tree classifier (DT) are used to classify the EEG signals. Results It is revealed that the accuracy between normal subjects with eyes open condition (data set A) epileptic data set E using SVM is obtained as 96.25%. Classification accuracy between the normal subjects with eye closed condition and epileptic data set E is obtained as 83.75%using k-NN classifier. Similar accuracies while discriminating the interictal data set C versus ictal data set E, and interictal data set D versus ictal data set E are obtained as 97.5% and 97.5% respectively, using a FFBPNN. These accuracies are quite higher than the earlier results published. The results are discussed quite in detail towards the last sections of the present paper. Conclusions Our experimental results demonstrate that the proposed method gives quite high statistical parameters for EEG classifications especially to classify the interictal data(C, D) and ictal data (E). These experiments indicate that the present method can be useful in analyzing and detecting the EEG signal associated with epilepsy.

Study of a High SO2 Event Observed over an Urban Site in Western India

Chinmay Mallik,S. Venkataramani,Shyam Lal 한국기상학회 2012 Asia-Pacific Journal of Atmospheric Sciences Vol.48 No.2

Continuous measurements of SO2, NOx and O3 along with sampling based measurements of CO, CH4, NMHCs and CO2 were carried out during May, 2010 at Ahmedabad. The diurnal variations of SO2 in ambient air exhibited elevated values during the night and lower levels during the sunlit hours. The mean concentration of SO2during the study period was 0.95 ± 0.88 ppbv. However, the ambient SO2 exceeded 17 ppbv in the night of 20 May, 2010. On the same day, tropospheric columnar SO2 from OMI showed almost 350% increase corroborating the surface observations over an extended height regime. This was also the highest columnar value of SO2 during the summer of 2010. Columnar loadings were also found to be high for formaldehyde, precipitable water vapor and aerosol optical depth on 20 May. Elevated concentrations were also recorded for other trace gases like NO2 and O3. Analysis of related data of trace gases indicated characteristics of fresh emissions with dominant contributions from mobile sources during the study period. However, SO2/NO2ratio of 0.36 during the event period on 20th May connotes non-local influences. Analyses of meteorological parameters suggest combined impacts of transport and inversion causing higher levels of SO2 and other pollutants during 20-21 May. Episodes of such enhancements may perturb chemical and radiative balance of the atmosphere.

Addendum: Improved postoperative recovery profile in pediatric oral rehabilitation with low-dose dexmedetomidine as an opioid substitute for general anesthesia: a randomized double-blind clinical trial

Naik B Naveen,Manoj Kumar Jaiswal,Venkata Ganesh,Ajay Singh,Shyam Charan Meena,Vamsidhar Amburu,Shiv Lal Soni 대한치과마취과학회 2023 Journal of Dental Anesthesia and Pain Medicine Vol.23 No.1

Improved postoperative recovery profile in pediatric oral rehabilitation with low-dose dexmedetomidine as an opioid substitute for general anesthesia: a randomized double-blind clinical trial

Naik B Naveen,Manoj Kumar Jaiswal,Venkata Ganesh,Ajay Singh,Shyam Charan Meena,Vamsidhar Amburu,Shiv Lal Soni 대한치과마취과학회 2022 Journal of Dental Anesthesia and Pain Medicine Vol.22 No.5

Background: Low-dose dexmedetomidine may be a suitable alternative to opioids for pediatric ambulatory procedures under general anesthesia (GA). However, the recovery profile remains unclear. Herein, we aimed to evaluate the effects of low-dose dexmedetomidine on the recovery profile of children. Methods: Seventy-two children undergoing ambulatory oral rehabilitation under GA were randomly and equally distributed into two groups (D and F). Group D received an infusion of dexmedetomidine 0.25 μg/kg for 4 min for induction, followed by maintenance of 0.4 μg/kg/h. Group F received an infusion of fentanyl 1 μg/kg over 4 min for induction, followed by maintenance at 1 μg/kg/h. The primary outcome was the extubation time. The secondary outcomes were awakening time, end-tidal sevoflurane (ET-Sevo) requirement, change in hemodynamic parameters, Richmond Agitation–Sedation Scale (RASS), Children's Hospital of Eastern Ontario pain scale (CHEOPS) score, length of PACU stay, and incidence of adverse events. Results: Statistically significant differences were observed in the recovery profile between the groups: the median time for extubation was 3.65 (3.44–6.2) vs. 6.25 (4.21–7) minutes in groups D vs. F (P=0.001), respectively, while the corresponding awakening times were 19 (18.75–21) and 22.5 (22–24) minutes, respectively (P < 0.001). The mean ET-Sevo was low in group D (1.1 vs. 1.2; P < 0.001). The heart rate was significantly low across all time points in group D, without resulting in bradycardia. The median RASS and CHEOPS scores were also significantly lower in group D. No significant differences were observed in the mean arterial pressure, incidence of adverse events, or length of PACU stay. Conclusion: Low-dose dexmedetomidine was more effective than fentanyl as an opioid substitute at providing a better recovery profile in pediatric ambulatory oral rehabilitation under GA. Dexmedetomidine also significantly reduced sevoflurane consumption without causing adverse events or prolonging hospital stay.