Apodization Defocused Optical Imaging System with Different Apertures using Hanning Amplitude Filter

The Optical system performance is characterized by the modulus and the phase of the amplitude impulse response (point spread function). An optical system with a nonuniform amplitude across its pupil called an apodized system. The motivation of apodizing a system is to increase the image quality of the system. In this paper, the influence of Hanning amplitude filters on the intensity of incoherent optical systems has been analyzed. A general expression for the PSF in the case of different square size pupil apertures (half diagonal=........

Thermal image segmentation based on density slicing of color histogram of images

Thermal imaging has been recently used as a new approach for human biometrics. The formation of thermal image is purely based on the heat distribution of an object. It brings some difficulties to image segmentation due to its over centralized intensity distribution and low intensity contrast. Our approach uses color slicing segmentation method to characterize the texture information using various color models. The experimental results of present study shows the color slicing technique can make good effect on the segmentation of tumor structure. We have found that segmenting these images can be made easier by using RGB, HSV, YCbCr color models by Color slicing method. We have used many Statistical operations (such as contrast, variation …) to evaluate our segmentation results

Enhancement of Underwater Image using Fuzzy Histogram Equalization

Image enhancement is a process of improving the quality of image by improving its feature. The underwater images suffer from low contrast and resolution due to scattering of light and poor visibility conditions. In this paper we proposed an image enhancement technique to enhance the quality of underwater images. The proposed technique comprises a combination of classical contrast enhancement techniques and fuzzyhistogram equalization techniques. For comparing the performance, some statistics parameter is used. The proposed technique comprises a combination of classical contrast enhancement techniques and fuzzy-histogram equalization techniques. Experiment results demonstrate the effectiveness of fuzzy logic techniques to enhance the quality of the underwater images

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used

Health-status outcomes with invasive or conservative care in coronary disease

BACKGROUND In the ISCHEMIA trial, an invasive strategy with angiographic assessment and revascularization did not reduce clinical events among patients with stable ischemic heart disease and moderate or severe ischemia. A secondary objective of the trial was to assess angina-related health status among these patients. METHODS We assessed angina-related symptoms, function, and quality of life with the Seattle Angina Questionnaire (SAQ) at randomization, at months 1.5, 3, and 6, and every 6 months thereafter in participants who had been randomly assigned to an invasive treatment strategy (2295 participants) or a conservative strategy (2322). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate differences between the treatment groups. The primary outcome of this health-status analysis was the SAQ summary score (scores range from 0 to 100, with higher scores indicating better health status). All analyses were performed in the overall population and according to baseline angina frequency. RESULTS At baseline, 35% of patients reported having no angina in the previous month. SAQ summary scores increased in both treatment groups, with increases at 3, 12, and 36 months that were 4.1 points (95% credible interval, 3.2 to 5.0), 4.2 points (95% credible interval, 3.3 to 5.1), and 2.9 points (95% credible interval, 2.2 to 3.7) higher with the invasive strategy than with the conservative strategy. Differences were larger among participants who had more frequent angina at baseline (8.5 vs. 0.1 points at 3 months and 5.3 vs. 1.2 points at 36 months among participants with daily or weekly angina as compared with no angina). CONCLUSIONS In the overall trial population with moderate or severe ischemia, which included 35% of participants without angina at baseline, patients randomly assigned to the invasive strategy had greater improvement in angina-related health status than those assigned to the conservative strategy. The modest mean differences favoring the invasive strategy in the overall group reflected minimal differences among asymptomatic patients and larger differences among patients who had had angina at baseline