Extending Camera's Capabilities in Low Light Conditions Based on LIP Enhancement Coupled with CNN Denoising.

Using a sensor in variable lighting conditions, especially very low-light conditions, requires the application of image enhancement followed by denoising to retrieve correct information. The limits of such a process are explored in the present paper, with the objective of preserving the quality of enhanced images. The LIP (Logarithmic Image Processing) framework was initially created to process images acquired in transmission. The compatibility of this framework with the human visual system makes possible its application to images acquired in reflection. Previous works have established the ability of the LIP laws to perform a precise simulation of exposure time variation. Such a simulation permits the enhancement of low-light images, but a denoising step is required, realized by using a CNN (Convolutional Neural Network). A main contribution of the paper consists of using rigorous tools (metrics) to estimate the enhancement reliability in terms of noise reduction, visual image quality, and color preservation. Thanks to these tools, it has been established that the standard exposure time can be significantly reduced, which considerably enlarges the use of a given sensor. Moreover, the contribution of the LIP enhancement and denoising step are evaluated separately.

Consensus study to define appropriate inaction and inappropriate inertia in the management of patients with hypertension in primary care.

OBJECTIVES: To elaborate and validate operational definitions for appropriate inaction and for inappropriate inertia in the management of patients with hypertension in primary care. DESIGN: A two-step approach was used to reach a definition consensus. First, nominal groups provided practice-based information on the two concepts. Second, a Delphi procedure was used to modify and validate the two definitions created from the nominal groups results. PARTICIPANTS: 14 French practicing general practitioners participated in each of the two nominal groups, held in two different areas in France. For the Delphi procedure, 30 academics, international experts in the field, were contacted; 20 agreed to participate and 19 completed the procedure. RESULTS: Inappropriate inertia was defined as: to not initiate or intensify an antihypertensive treatment for a patient who is not at the blood pressure goals defined for this patient in the guidelines when all following conditions are fulfilled: (1) elevated blood pressure has been confirmed by self-measurement or ambulatory blood pressure monitoring, (2) there is no legitimate doubt on the reliability of the measurements, (3) there is no observance issue regarding pharmacological treatment, (4) there is no specific iatrogenic risk (which alters the risk-benefit balance of treatment for this patient), in particular orthostatic hypotension in the elderly, (5) there is no other medical priority more important and more urgent, and (6) access to treatment is not difficult. Appropriate inaction was defined as the exact mirror, that is, when at least one of the above conditions is not met. CONCLUSION: Definitions of appropriate inaction and inappropriate inertia in the management of patients with hypertension have been established from empirical practice-based data and validated by an international panel of academics as useful for practice and research.