The document evaluates techniques for expanding a camera's dynamic range using defocus blurring and deconvolution. It tests various aperture filters and deconvolution algorithms on sample images to determine the amount of dynamic range reduction achieved with acceptable final image quality. The best performing combination was able to reduce dynamic range by over 2 stops for one image and 4.5 stops for another, while maintaining PSNR values over 35 dB.
The document discusses computational photography and the future of cameras. It describes how cameras could encode light in time and space using coded apertures and flutter shutters to capture more information from a single photo. This would allow for features like digital refocusing and motion deblurring. It also discusses using masks inside cameras to capture 4D light field data with a 2D sensor, and how this could enable features like refocusing after the photo is taken. Finally, it proposes new types of cameras that could reconstruct 3D shape from a single photo or enable high-speed motion capture using imperceptible projected patterns.
The UP-DF750 is a compact digital film imager that provides high-quality 604 dpi images on various film sizes. It has a small footprint and can be vertically mounted. The UP-DF750 uses proven Sony thermal printing technology and is suitable for general radiology as well as mammography imaging. It has configurable settings, language support, and DICOM connectivity for integration into medical imaging networks.
The document discusses various factors that affect the mapping of light intensity arriving at a camera lens to digital pixel values stored in an image file. It describes the radiometric response function, vignetting, and point spread function, which characterize how light is mapped and degraded by the camera imaging system. Sources of noise during image sensing and processing steps are also outlined. Methods to model and remove vignetting effects as well as deconvolve blur and noise in images using estimated point spread functions and noise levels are presented.
1. Ramesh Raskar discusses his research in computational photography and creating new types of cameras that go beyond traditional camera capabilities.
2. The goal is to develop imaging platforms that have a deeper understanding of the visual world than humans by capturing and analyzing more information.
3. Examples of this research include cameras that can capture light fields and refocus images after capture, cameras that can remove motion blur in a single photo, and techniques for capturing high-speed motion with imperceptible tags.
Spatial resolution refers to the ability to distinguish between two close objects or fine detail in an image. It depends on properties of the imaging system, not just pixel count. Higher spatial resolution means finer details can be distinguished. Pixel count alone does not determine spatial resolution, as color images require interpolation between sensor pixels. Spatial resolution is measured differently for various media like film, digital cameras, microscopes, and more. It affects the ability to distinguish fine detail like gaps in a fence as distance increases.
This document discusses image characteristics and film processing in dental radiography. It begins by defining key terms like density, contrast, sharpness, magnification, and distortion which describe ideal radiographic image quality. Factors that influence these characteristics such as film speed, object distance, and tube settings are explained. The formation of latent images on film from x-ray exposure is also covered. Finally, the importance of a darkroom for safely processing films to convert latent images into visible radiographs without additional exposure is highlighted.
This document discusses fundamentals of imaging and image processing. It describes features of human vision including the retina, cones, and rods. Cones are sensitive to color while rods provide a general picture. Images are formed in the eye based on the height and focal length. The human visual system can adapt to a wide range of light intensities but can only perceive a small sub-range at a time. Electromagnetic waves carry energy proportional to their frequency. Digital images are discrete functions defined over a spatial domain with intensity values. Image formation depends on illumination and reflectance. Sampling digitizes spatial coordinates while quantization digitizes intensities into discrete levels. The sampling theorem establishes that a signal can be reconstructed from samples if the sampling rate exceeds
Photoflurography new microsoft office powerpoint 97 2003 presentationmr_koky
1. Photofluorography is the process of taking photographs of images produced on the output phosphor of an image intensifier during fluoroscopy. (2) For non-digital fluoroscopy systems, images were recorded using film-screen radiography, serial cameras, or cine cameras. (3) Serial cameras and cine cameras allowed photos or rapid sequences of photos to be taken from the image intensifier output, a process known as fluorography.
The document discusses computational photography and the future of cameras. It describes how cameras could encode light in time and space using coded apertures and flutter shutters to capture more information from a single photo. This would allow for features like digital refocusing and motion deblurring. It also discusses using masks inside cameras to capture 4D light field data with a 2D sensor, and how this could enable features like refocusing after the photo is taken. Finally, it proposes new types of cameras that could reconstruct 3D shape from a single photo or enable high-speed motion capture using imperceptible projected patterns.
The UP-DF750 is a compact digital film imager that provides high-quality 604 dpi images on various film sizes. It has a small footprint and can be vertically mounted. The UP-DF750 uses proven Sony thermal printing technology and is suitable for general radiology as well as mammography imaging. It has configurable settings, language support, and DICOM connectivity for integration into medical imaging networks.
The document discusses various factors that affect the mapping of light intensity arriving at a camera lens to digital pixel values stored in an image file. It describes the radiometric response function, vignetting, and point spread function, which characterize how light is mapped and degraded by the camera imaging system. Sources of noise during image sensing and processing steps are also outlined. Methods to model and remove vignetting effects as well as deconvolve blur and noise in images using estimated point spread functions and noise levels are presented.
1. Ramesh Raskar discusses his research in computational photography and creating new types of cameras that go beyond traditional camera capabilities.
2. The goal is to develop imaging platforms that have a deeper understanding of the visual world than humans by capturing and analyzing more information.
3. Examples of this research include cameras that can capture light fields and refocus images after capture, cameras that can remove motion blur in a single photo, and techniques for capturing high-speed motion with imperceptible tags.
Spatial resolution refers to the ability to distinguish between two close objects or fine detail in an image. It depends on properties of the imaging system, not just pixel count. Higher spatial resolution means finer details can be distinguished. Pixel count alone does not determine spatial resolution, as color images require interpolation between sensor pixels. Spatial resolution is measured differently for various media like film, digital cameras, microscopes, and more. It affects the ability to distinguish fine detail like gaps in a fence as distance increases.
This document discusses image characteristics and film processing in dental radiography. It begins by defining key terms like density, contrast, sharpness, magnification, and distortion which describe ideal radiographic image quality. Factors that influence these characteristics such as film speed, object distance, and tube settings are explained. The formation of latent images on film from x-ray exposure is also covered. Finally, the importance of a darkroom for safely processing films to convert latent images into visible radiographs without additional exposure is highlighted.
This document discusses fundamentals of imaging and image processing. It describes features of human vision including the retina, cones, and rods. Cones are sensitive to color while rods provide a general picture. Images are formed in the eye based on the height and focal length. The human visual system can adapt to a wide range of light intensities but can only perceive a small sub-range at a time. Electromagnetic waves carry energy proportional to their frequency. Digital images are discrete functions defined over a spatial domain with intensity values. Image formation depends on illumination and reflectance. Sampling digitizes spatial coordinates while quantization digitizes intensities into discrete levels. The sampling theorem establishes that a signal can be reconstructed from samples if the sampling rate exceeds
Photoflurography new microsoft office powerpoint 97 2003 presentationmr_koky
1. Photofluorography is the process of taking photographs of images produced on the output phosphor of an image intensifier during fluoroscopy. (2) For non-digital fluoroscopy systems, images were recorded using film-screen radiography, serial cameras, or cine cameras. (3) Serial cameras and cine cameras allowed photos or rapid sequences of photos to be taken from the image intensifier output, a process known as fluorography.
Night Vision Technology was presented by Divyaprathapraju.D. The document discusses three main night vision technologies: 1) Image intensification which amplifies low levels of light, 2) Active illumination which uses infrared light to illuminate scenes, and 3) Thermal imaging which detects infrared radiation emitted by objects. Night vision has military, law enforcement, wildlife observation, and security applications by enabling vision in low light conditions. It has progressed through multiple generations with improvements such as smaller sizes and higher resolutions.
Haze is cloudiness caused by light scattering from particles or imperfect surfaces. It can be quantified for materials like liquids, glass, plastics, and metals. Transmission haze is measured by light transmitted through a sample, while reflection haze is measured by light reflected off opaque surfaces. Current HunterLab instruments measure haze similarly but not identically to ASTM standards due to instrument design differences. Measurements of several samples showed similar but not identical haze values between instrument models.
Choosing a solar ultraviolet simulator with an appropriate spectrumFrançois Christiaens
The goal of solar ultraviolet (UV) simulation is to reproduce the natural solar UV spectrum. However, this spectrum changes continuously depending on parameters, such as latitude, season, time, cloudiness, etc. From spectra recorded worldwide throughout the year, a realistic ("standard") solar UV spectrum at Earth level was defined by the Deutsches Institut f|r Normung e.V. (DIN) to represent a "worst" case situation. Exposure of human skin to such a spectrum is likely to result in intense biological effects. Simulated solar UV spectra should match the standard spectrum as closely as possible. Here, we present a method to assess the match between a laboratory spectrum and the standard spectrum. Representative UV sources such as xenon arcs, metal halide lamps and fluorescent tubes, along with various filters, have been measured. Differences between the relative irradiance of UV candidate spectra and the standard are calculated for each wavelength. These differences are squared and summed. The lower the sum, the better the match of the source spectrum to the standard sun. This method may be used with or without biological weighting by an action spectrum. We have selected the erythema action spectrum to assess and rank candidate sources. Our analysis shows that filtered ultraviolet B fluorescent tubes are the worst way of simulating solar radiation, with and without weighting by the erythema action spectrum. UV spectra from solaria equipped with combinations of ultraviolet A and ultraviolet B fluorescent tubes are also far from satisfactory. In general, metal halide lamps rank slightly better than the fluorescent UVB tubes. The choice of UV filter plays a significant role in the compliance of candidate UV source. In conclusion, the suggested method allows the determination of the most appropriate UV source to simulate real solar exposure for any targeted biological damage.
ASC 3D is a 3D camera semiconductor company founded in 1987 that designs semiconductors, lasers, optics, and 3D Flash LIDAR cameras. It has multiple patents granted and several more pending. Its unique 3D Flash LIDAR technology can generate real-time 3D images and depth maps without motion distortion for applications such as autonomous vehicles, drones, industrial automation, and more. The technology offers advantages over other 3D solutions such as being lightweight, eye-safe, and not requiring moving parts.
Comparing the Performance of Different Ultrasonic Image Enhancement Technique...Md. Shohel Rana
Medical ultrasound US images are usually corrupted by speckle noise during their acquisition. De-noising techniques are to remove noises while retaining the important signal features. Preservation of the image sharpness and details while suppressing the speckle noise. A novel restoration scheme has been introduced for ultrasound (US) images for speckle reduction which enhances the signal-to-noise ratio while conserving the edges and lines in the image
The document discusses using coded masks and modulation techniques to capture light field information and enable digital refocusing and 6D displays with a single 2D sensor. It proposes placing a coded mask in front of the sensor to heterodyne the light field and extract its 4D information. Several applications are mentioned, including coded illumination for motion capture, a 6D display using spatial and illumination variation, and a light field camera that can digitally refocus using a single photograph.
This document summarizes a method for estimating depth from a single image taken with a coded aperture camera. It begins by discussing challenges with conventional depth from defocus techniques. It then presents two key ideas: 1) using natural image priors for improved deconvolution and 2) adding a coded pattern to the camera aperture to make blur patterns more discriminable for scale estimation. The coded aperture design aims to avoid issues like division by zero that can occur with conventional apertures. Results show the method enables applications like all-in-focus imaging and digital refocusing from a single shot.
Accelarating Optical Quadrature Microscopy Using GPUsPerhaad Mistry
1) Phase unwrapping is used in optical quadrature microscopy to determine viability of embryos by counting cells after unwrapping. It needs to be done at near real-time speeds to analyze sample changes.
2) The paper implements minimum LP norm phase unwrapping and affine transformations on a GPU to improve performance and latency for optical microscopy research.
3) Performance results show a 5.24x speedup for total phase unwrapping time compared to a serial CPU implementation. Further optimizations like multi-GPU support could improve speeds for higher image acquisition rates.
This document discusses different types of radiography detectors, focusing on radiographic film. It describes the components and construction of radiographic film, including the base, emulsion, and silver halide crystals. It explains how x-rays or light from intensifying screens interact with the emulsion to create a latent image. Key factors for selecting radiographic film types are also summarized, such as contrast, speed, resolution, crossover effects, spectral matching of screens and film, and safelighting considerations.
This document describes the design and operation of a DIY spectrometer built using an improvised concave diffraction grating. Light enters through a slit and is separated by wavelength when reflected off the grating. Each wavelength is focused onto a linear sensor array, which records the intensity. An Arduino microcontroller interprets the sensor data and sends it to a computer program that displays a spectrum graph in real-time. The spectrometer can characterize various light sources across ultraviolet to infrared wavelengths, including LEDs, fluorescent lamps, and white light sources. Further improvements are suggested to refine the device and add calibration features.
This document describes the concept of dual photography, which uses Helmholtz reciprocity to interchange lights and cameras in a scene. It discusses how the transposed transport matrix can be used to generate virtual captured images from virtual projected patterns. It also describes different methods used to capture the transport matrix, including fixed pattern scanning and adaptive multiplexed illumination. Limitations discussed include scenes with significant global illumination effects and situations where the camera and projector are at a large angle.
Classification of Fonts and Calligraphy Styles based on Complex Wavelet Trans...Alican Bozkurt
This document discusses optical character recognition (OCR) and font recognition techniques. It presents the results of several experiments comparing different OCR and font recognition algorithms on various datasets containing English, Farsi, Arabic, and Ottoman fonts and styles. The proposed dual tree complex wavelet transform (DT-CWT) approach achieved higher accuracy than state-of-the-art methods on most datasets, was faster, and was more robust to noise. Mean and standard deviation of wavelet coefficients were used as features with an SVM classifier.
IDEAL IMAGE CHARACTERISTICS
FACTORS RELATED TO THE RADIATION BEAM
FACTORS RELATED TO THE OBJECT
FACTORS RELATED TO THE TECHNIQUE
FACTORS RELATED TO RECORDING OF THE ROENTGEN IMAGE OF THE OBJECT
DARK/ LIGHT IMAGE IDEAL IMAGE
IDEAL QUALITY CRIETRIA
This document discusses two types of distortion that can occur in radiography: size distortion and shape distortion. Size distortion refers to unequal magnification and is influenced by the object-to-film distance and film-to-focus distance. Shape distortion occurs when there is elongation or foreshortening due to the central ray-part-film alignment. Magnification radiography can be used intentionally to visualize small structures and comes at the cost of increased patient dose. Proper technique such as parallel part-film alignment and perpendicular central ray direction can minimize distortion.
The document proposes a multi-aperture camera that can capture images at multiple aperture settings simultaneously. This allows for post-exposure control of depth of field and limited refocusing capabilities. The camera uses a relay system to split the aperture into separate optical paths and capture light through different sections of the aperture on a single image sensor. This enables extrapolating shallow depth of field beyond the physically largest aperture of the camera and refocusing the image after capture.
1. Sensitometry involves measuring the sensitivity of photographic film to radiation through analysis of the characteristic curve, which plots density versus log exposure.
2. To generate the characteristic curve, film is exposed to a range of known radiation levels using methods like variable exposure times or stepped wedges. The resulting densities are then measured and plotted.
3. The characteristic curve shows the film's response over a wide exposure range and possesses features like a toe, shoulder, and straight line regions that indicate under, over, and properly exposed areas of the film.
The document summarizes the design of a flashlight collimating system. It discusses properties of LED emitters and the objective to collimate light into a bright hotspot to increase throw. A collimating system typically uses a reflector, lens, or optics combination. Reflectors can vary the depth to diameter ratio to control hotspot size and spill light. Lenses can form a sharp image of the emitter but require addressing chromatic aberration. Optics provide more flexibility and allow total internal reflection for high efficiency. The document proposes improving reflective coatings and developing optimized reflector-like optics.
1. The document discusses image formation, cameras, and digital image acquisition and representation. It describes how images are formed through light projection and sampling, and how analog and digital cameras work to capture images.
2. Digital images are represented as matrices, with each element corresponding to a pixel value. Grayscale images have a single value per pixel while color images have multiple values representing channels like red, green, and blue.
3. Pixels in digital images are quantized to a finite set of numeric values like 8-bit integers from 0 to 255 for storage and processing in computer systems. This affects qualities like radiometric resolution of the encoded image.
The document describes the engineering design process and finite element analysis (FEA). It summarizes that the engineering design process is iterative and involves research, conceptualization, design, and production. It then explains that FEA uses the finite element method to approximate solutions to partial differential equations by dividing a complex problem into smaller, solvable elements. FEA is well-suited for problems over complicated domains, changing domains, solutions with varying precision, or non-smooth solutions like crash simulations.
Night Vision Technology was presented by Divyaprathapraju.D. The document discusses three main night vision technologies: 1) Image intensification which amplifies low levels of light, 2) Active illumination which uses infrared light to illuminate scenes, and 3) Thermal imaging which detects infrared radiation emitted by objects. Night vision has military, law enforcement, wildlife observation, and security applications by enabling vision in low light conditions. It has progressed through multiple generations with improvements such as smaller sizes and higher resolutions.
Haze is cloudiness caused by light scattering from particles or imperfect surfaces. It can be quantified for materials like liquids, glass, plastics, and metals. Transmission haze is measured by light transmitted through a sample, while reflection haze is measured by light reflected off opaque surfaces. Current HunterLab instruments measure haze similarly but not identically to ASTM standards due to instrument design differences. Measurements of several samples showed similar but not identical haze values between instrument models.
Choosing a solar ultraviolet simulator with an appropriate spectrumFrançois Christiaens
The goal of solar ultraviolet (UV) simulation is to reproduce the natural solar UV spectrum. However, this spectrum changes continuously depending on parameters, such as latitude, season, time, cloudiness, etc. From spectra recorded worldwide throughout the year, a realistic ("standard") solar UV spectrum at Earth level was defined by the Deutsches Institut f|r Normung e.V. (DIN) to represent a "worst" case situation. Exposure of human skin to such a spectrum is likely to result in intense biological effects. Simulated solar UV spectra should match the standard spectrum as closely as possible. Here, we present a method to assess the match between a laboratory spectrum and the standard spectrum. Representative UV sources such as xenon arcs, metal halide lamps and fluorescent tubes, along with various filters, have been measured. Differences between the relative irradiance of UV candidate spectra and the standard are calculated for each wavelength. These differences are squared and summed. The lower the sum, the better the match of the source spectrum to the standard sun. This method may be used with or without biological weighting by an action spectrum. We have selected the erythema action spectrum to assess and rank candidate sources. Our analysis shows that filtered ultraviolet B fluorescent tubes are the worst way of simulating solar radiation, with and without weighting by the erythema action spectrum. UV spectra from solaria equipped with combinations of ultraviolet A and ultraviolet B fluorescent tubes are also far from satisfactory. In general, metal halide lamps rank slightly better than the fluorescent UVB tubes. The choice of UV filter plays a significant role in the compliance of candidate UV source. In conclusion, the suggested method allows the determination of the most appropriate UV source to simulate real solar exposure for any targeted biological damage.
ASC 3D is a 3D camera semiconductor company founded in 1987 that designs semiconductors, lasers, optics, and 3D Flash LIDAR cameras. It has multiple patents granted and several more pending. Its unique 3D Flash LIDAR technology can generate real-time 3D images and depth maps without motion distortion for applications such as autonomous vehicles, drones, industrial automation, and more. The technology offers advantages over other 3D solutions such as being lightweight, eye-safe, and not requiring moving parts.
Comparing the Performance of Different Ultrasonic Image Enhancement Technique...Md. Shohel Rana
Medical ultrasound US images are usually corrupted by speckle noise during their acquisition. De-noising techniques are to remove noises while retaining the important signal features. Preservation of the image sharpness and details while suppressing the speckle noise. A novel restoration scheme has been introduced for ultrasound (US) images for speckle reduction which enhances the signal-to-noise ratio while conserving the edges and lines in the image
The document discusses using coded masks and modulation techniques to capture light field information and enable digital refocusing and 6D displays with a single 2D sensor. It proposes placing a coded mask in front of the sensor to heterodyne the light field and extract its 4D information. Several applications are mentioned, including coded illumination for motion capture, a 6D display using spatial and illumination variation, and a light field camera that can digitally refocus using a single photograph.
This document summarizes a method for estimating depth from a single image taken with a coded aperture camera. It begins by discussing challenges with conventional depth from defocus techniques. It then presents two key ideas: 1) using natural image priors for improved deconvolution and 2) adding a coded pattern to the camera aperture to make blur patterns more discriminable for scale estimation. The coded aperture design aims to avoid issues like division by zero that can occur with conventional apertures. Results show the method enables applications like all-in-focus imaging and digital refocusing from a single shot.
Accelarating Optical Quadrature Microscopy Using GPUsPerhaad Mistry
1) Phase unwrapping is used in optical quadrature microscopy to determine viability of embryos by counting cells after unwrapping. It needs to be done at near real-time speeds to analyze sample changes.
2) The paper implements minimum LP norm phase unwrapping and affine transformations on a GPU to improve performance and latency for optical microscopy research.
3) Performance results show a 5.24x speedup for total phase unwrapping time compared to a serial CPU implementation. Further optimizations like multi-GPU support could improve speeds for higher image acquisition rates.
This document discusses different types of radiography detectors, focusing on radiographic film. It describes the components and construction of radiographic film, including the base, emulsion, and silver halide crystals. It explains how x-rays or light from intensifying screens interact with the emulsion to create a latent image. Key factors for selecting radiographic film types are also summarized, such as contrast, speed, resolution, crossover effects, spectral matching of screens and film, and safelighting considerations.
This document describes the design and operation of a DIY spectrometer built using an improvised concave diffraction grating. Light enters through a slit and is separated by wavelength when reflected off the grating. Each wavelength is focused onto a linear sensor array, which records the intensity. An Arduino microcontroller interprets the sensor data and sends it to a computer program that displays a spectrum graph in real-time. The spectrometer can characterize various light sources across ultraviolet to infrared wavelengths, including LEDs, fluorescent lamps, and white light sources. Further improvements are suggested to refine the device and add calibration features.
This document describes the concept of dual photography, which uses Helmholtz reciprocity to interchange lights and cameras in a scene. It discusses how the transposed transport matrix can be used to generate virtual captured images from virtual projected patterns. It also describes different methods used to capture the transport matrix, including fixed pattern scanning and adaptive multiplexed illumination. Limitations discussed include scenes with significant global illumination effects and situations where the camera and projector are at a large angle.
Classification of Fonts and Calligraphy Styles based on Complex Wavelet Trans...Alican Bozkurt
This document discusses optical character recognition (OCR) and font recognition techniques. It presents the results of several experiments comparing different OCR and font recognition algorithms on various datasets containing English, Farsi, Arabic, and Ottoman fonts and styles. The proposed dual tree complex wavelet transform (DT-CWT) approach achieved higher accuracy than state-of-the-art methods on most datasets, was faster, and was more robust to noise. Mean and standard deviation of wavelet coefficients were used as features with an SVM classifier.
IDEAL IMAGE CHARACTERISTICS
FACTORS RELATED TO THE RADIATION BEAM
FACTORS RELATED TO THE OBJECT
FACTORS RELATED TO THE TECHNIQUE
FACTORS RELATED TO RECORDING OF THE ROENTGEN IMAGE OF THE OBJECT
DARK/ LIGHT IMAGE IDEAL IMAGE
IDEAL QUALITY CRIETRIA
This document discusses two types of distortion that can occur in radiography: size distortion and shape distortion. Size distortion refers to unequal magnification and is influenced by the object-to-film distance and film-to-focus distance. Shape distortion occurs when there is elongation or foreshortening due to the central ray-part-film alignment. Magnification radiography can be used intentionally to visualize small structures and comes at the cost of increased patient dose. Proper technique such as parallel part-film alignment and perpendicular central ray direction can minimize distortion.
The document proposes a multi-aperture camera that can capture images at multiple aperture settings simultaneously. This allows for post-exposure control of depth of field and limited refocusing capabilities. The camera uses a relay system to split the aperture into separate optical paths and capture light through different sections of the aperture on a single image sensor. This enables extrapolating shallow depth of field beyond the physically largest aperture of the camera and refocusing the image after capture.
1. Sensitometry involves measuring the sensitivity of photographic film to radiation through analysis of the characteristic curve, which plots density versus log exposure.
2. To generate the characteristic curve, film is exposed to a range of known radiation levels using methods like variable exposure times or stepped wedges. The resulting densities are then measured and plotted.
3. The characteristic curve shows the film's response over a wide exposure range and possesses features like a toe, shoulder, and straight line regions that indicate under, over, and properly exposed areas of the film.
The document summarizes the design of a flashlight collimating system. It discusses properties of LED emitters and the objective to collimate light into a bright hotspot to increase throw. A collimating system typically uses a reflector, lens, or optics combination. Reflectors can vary the depth to diameter ratio to control hotspot size and spill light. Lenses can form a sharp image of the emitter but require addressing chromatic aberration. Optics provide more flexibility and allow total internal reflection for high efficiency. The document proposes improving reflective coatings and developing optimized reflector-like optics.
1. The document discusses image formation, cameras, and digital image acquisition and representation. It describes how images are formed through light projection and sampling, and how analog and digital cameras work to capture images.
2. Digital images are represented as matrices, with each element corresponding to a pixel value. Grayscale images have a single value per pixel while color images have multiple values representing channels like red, green, and blue.
3. Pixels in digital images are quantized to a finite set of numeric values like 8-bit integers from 0 to 255 for storage and processing in computer systems. This affects qualities like radiometric resolution of the encoded image.
The document describes the engineering design process and finite element analysis (FEA). It summarizes that the engineering design process is iterative and involves research, conceptualization, design, and production. It then explains that FEA uses the finite element method to approximate solutions to partial differential equations by dividing a complex problem into smaller, solvable elements. FEA is well-suited for problems over complicated domains, changing domains, solutions with varying precision, or non-smooth solutions like crash simulations.
Information Visualization: See Patterns, Gain Insights & Make DecisionsUniversity of Maryland
This document summarizes information visualization research led by Ben Shneiderman at the University of Maryland. It discusses challenges in visualizing massive datasets and developing interaction techniques. It provides examples of visualization tools developed by Shneiderman's lab to analyze patient histories, gene ontologies, markets, networks, and text. The mantra of overview, zoom, filter and details-on-demand is emphasized for effective visualization.
This thesis describes the design and implementation of a star tracker for CubeSats. The author designed hardware modules for real-time star detection and centroid calculation using an FPGA. An image sensor and lens were selected, and a baffle was designed. Noise correction algorithms were developed. Testing showed the star tracker could detect stars up to magnitude 4.0 with sub-pixel centroiding accuracy of 0.0536 degrees. Future work includes integrating modules into an FPGA, implementing star identification and attitude algorithms, and testing the complete system.
[論文紹介] DPSNet: End-to-end Deep Plane Sweep StereoSeiya Ito
DPSNet is an end-to-end deep learning model that estimates dense depth maps from stereo image pairs. It generates cost volumes from multi-scale feature maps of reference and paired images. It then refines the cost slices with dilated convolutions considering contextual information. Finally, it regresses the depth maps from the initial and refined cost volumes. Evaluation on various datasets shows DPSNet achieves state-of-the-art performance in depth map estimation, outperforming other methods in terms of accuracy metrics while maintaining full completeness of predictions.
This document discusses using the data mining tool WEKA to perform linear regression and clustering on a dataset. WEKA is an open source software that can be used to load data files, perform predictive modeling and data analysis. The document demonstrates using WEKA to create a linear regression model to predict prices based on attributes like BTU/Hr, weight, EER and region. It also shows how to create an EM clustering model in WEKA that clusters the data into 5 groups based on the attributes.
The document discusses using the data mining tool WEKA to perform linear regression and clustering analysis. It provides steps for loading the housing unit dataset and building linear regression and EM clustering models in WEKA. The linear regression output shows the attributes that predict housing unit price. The clustering analysis identifies 5 clusters in the data and provides details on the attribute means and standard deviations for each cluster.
This documents presents DELPH workflow for handling side-scan sonar data. It describes all steps from sensor acquisition to data processing and mapping.
Ben Shneiderman is a professor of computer science at the University of Maryland who researches information visualization for knowledge discovery. His research community focuses on interdisciplinary work at the intersection of computer science, information studies, and social sciences. Some of the key challenges in information visualization that he addresses are creating meaningful visual displays of massive data, enabling user interaction through widgets and window coordination, and developing process models for knowledge discovery.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
The document describes modifications made to a log periodic dipole antenna (LPDA) to make it more portable while maintaining performance. Specifically:
- The original LPDA had a boom length of 5.5 meters, which was reduced to 3.11 meters to improve portability.
- 38 elements were used on two booms to cover frequencies from 45MHz to 1000MHz. Plastic insulation and a spacing factor of 0.08 were used.
- The antenna was connected to a CALLISTO spectrometer via coaxial cable to convert radio signals for detection and measurement of solar bursts.
- Initial results showed the modified compact LPDA operated successfully while maintaining the desired frequency range and directivity.
Mapping and classification of spatial data using machine learning: algorithms...Beniamino Murgante
This document summarizes the results of a spatial interpolation comparison exercise conducted in 2004. Participants were asked to estimate pollution values at 1008 locations based on observations from 200 random monitoring locations. The best results in the emergency scenario came from methods using neural networks, with one participant achieving a mean absolute error of 14.85. Geostatistical methods also performed well overall, with many participants achieving errors less than 20. The results are presented in a table ranking methods by their performance in the emergency scenario.
Improved Visualization, Counting and Sizing of Polydisperse Nanoparticle Coll...HORIBA Particle
The ViewSizer® 3000 offers the ability to visualize nanoparticle colloids without requiring calibration standards or knowledge of any particle material properties, such as refractive index. It was developed by MANTA – the Most Advanced Nanoparticle Tracking Analysis – and offers the user an unprecedented ability to count and size highly polydispersed samples, such as milk, sea water, or blood plasma.
View recorded webinars:
http://bit.ly/particlewebinars
This document discusses two mass spectrometry techniques for analyzing proteins and peptides - electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). It provides an overview of how each technique works, including that ESI involves applying a high voltage to charge droplets containing sample which evaporate until single charged molecules enter the mass spectrometer, while MALDI involves mixing sample with an absorbing matrix that facilitates sublimation of ions into the gas phase with a laser. The document also compares advantages and disadvantages of each method, such as ESI being suitable for larger molecules and online coupling while MALDI provides quick, sensitive analysis of small amounts of sample. Examples of spectra from each technique analyzing can
This is a straightforward image classification study to create and compare classifiers (KNN, Neural Networks and Adaboost) that decide the correct orientation of a given image i.e. 0°,90°,180° or 270°
Panoramic Video in Environmental Monitoring Software Development and Applica...pycontw
This document summarizes a presentation on using panoramic video from a Ladybug3 360-degree spherical camera for environmental monitoring applications. The presentation covers using Python and APIs to access and process Ladybug video, applying techniques like SIFT and OpenCV to match images and derive flow fields, and discusses challenges with GPS data accuracy and developing a method for correcting panoramic image orientation. The goal is to allow analyzing related views across videos for tasks like measuring landslide sizes over time.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
1) The document discusses various techniques for edge detection in digital images, including differential operators, log operators, Canny operators, and binary morphology.
2) It first performs wavelet-based denoising on input images to remove noise before edge detection.
3) It then applies different edge detection operators and compares their advantages and disadvantages through simulations. Binary morphology is shown to obtain better edge features compared to other operators.
4) The overall goal is to extract clear and complete edge profiles from images to aid in tasks like image segmentation.
Implementation of Power Gating Technique in CMOS Full Adder Cell to Reduce Le...Amit Bakshi
1) The document presents a design for a 1-bit full adder cell that implements power gating techniques to reduce leakage power and ground bounce noise for use in mobile applications.
2) A sleep transistor is added between the actual ground rail and circuit ground to cut off the leakage path during sleep mode.
3) Stacking power gating with a delayed select input is also implemented and shown to further minimize both leakage power and ground bounce noise.
4) Simulation results demonstrate that the proposed design significantly reduces active power and standby leakage power compared to a conventional CMOS full adder cell.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/temporal-event-neural-networks-a-more-efficient-alternative-to-the-transformer-a-presentation-from-brainchip/
Chris Jones, Director of Product Management at BrainChip , presents the “Temporal Event Neural Networks: A More Efficient Alternative to the Transformer” tutorial at the May 2024 Embedded Vision Summit.
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Integration with BrainChip’s Akida neuromorphic hardware IP further enhances TENNs’ capabilities, enabling the realization of highly capable, portable and passively cooled edge devices. This presentation delves into the technical innovations underlying TENNs, presents real-world benchmarks, and elucidates how this cutting-edge approach is positioned to revolutionize edge AI across diverse applications.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
Fueling AI with Great Data with Airbyte WebinarZilliz
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Skybuffer SAM4U tool for SAP license adoptionTatiana Kojar
Manage and optimize your license adoption and consumption with SAM4U, an SAP free customer software asset management tool.
SAM4U, an SAP complimentary software asset management tool for customers, delivers a detailed and well-structured overview of license inventory and usage with a user-friendly interface. We offer a hosted, cost-effective, and performance-optimized SAM4U setup in the Skybuffer Cloud environment. You retain ownership of the system and data, while we manage the ABAP 7.58 infrastructure, ensuring fixed Total Cost of Ownership (TCO) and exceptional services through the SAP Fiori interface.
In the realm of cybersecurity, offensive security practices act as a critical shield. By simulating real-world attacks in a controlled environment, these techniques expose vulnerabilities before malicious actors can exploit them. This proactive approach allows manufacturers to identify and fix weaknesses, significantly enhancing system security.
This presentation delves into the development of a system designed to mimic Galileo's Open Service signal using software-defined radio (SDR) technology. We'll begin with a foundational overview of both Global Navigation Satellite Systems (GNSS) and the intricacies of digital signal processing.
The presentation culminates in a live demonstration. We'll showcase the manipulation of Galileo's Open Service pilot signal, simulating an attack on various software and hardware systems. This practical demonstration serves to highlight the potential consequences of unaddressed vulnerabilities, emphasizing the importance of offensive security practices in safeguarding critical infrastructure.
How information systems are built or acquired puts information, which is what they should be about, in a secondary place. Our language adapted accordingly, and we no longer talk about information systems but applications. Applications evolved in a way to break data into diverse fragments, tightly coupled with applications and expensive to integrate. The result is technical debt, which is re-paid by taking even bigger "loans", resulting in an ever-increasing technical debt. Software engineering and procurement practices work in sync with market forces to maintain this trend. This talk demonstrates how natural this situation is. The question is: can something be done to reverse the trend?
FREE A4 Cyber Security Awareness Posters-Social Engineering part 3Data Hops
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HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Introduction of Cybersecurity with OSS at Code Europe 2024Hiroshi SHIBATA
I develop the Ruby programming language, RubyGems, and Bundler, which are package managers for Ruby. Today, I will introduce how to enhance the security of your application using open-source software (OSS) examples from Ruby and RubyGems.
The first topic is CVE (Common Vulnerabilities and Exposures). I have published CVEs many times. But what exactly is a CVE? I'll provide a basic understanding of CVEs and explain how to detect and handle vulnerabilities in OSS.
Next, let's discuss package managers. Package managers play a critical role in the OSS ecosystem. I'll explain how to manage library dependencies in your application.
I'll share insights into how the Ruby and RubyGems core team works to keep our ecosystem safe. By the end of this talk, you'll have a better understanding of how to safeguard your code.
Best 20 SEO Techniques To Improve Website Visibility In SERPPixlogix Infotech
Boost your website's visibility with proven SEO techniques! Our latest blog dives into essential strategies to enhance your online presence, increase traffic, and rank higher on search engines. From keyword optimization to quality content creation, learn how to make your site stand out in the crowded digital landscape. Discover actionable tips and expert insights to elevate your SEO game.
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Topics covered:
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• How do the organization’s priorities determine CoE Structure?
Speaker:
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HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
Defocus Techniques for Camera Dynamic Range Expansion
1. Defocus Techniques for
Camera Dynamic Range
Expansion
Matthew Trentacoste, Cheryl Lau, Mushfiqur Rouf,
Rafal Mantiuk, Wolfgang Heidrich
University of British Columbia
2. Defocus DR expansion
• Sensorsexpanded, dynamic rangeexist
Can be
limited in
but tradeoffs
• Evaluate the scene incident onthe dynamic
range of
the opposite, reduce
the sensor
by optical blurring, restore in software
1/9 1/9 1/9 5/9 5/9 5/9
5 1/9 1/9 1/9
= 5/9 5/9 5/9
1/9 1/9 1/9 5/9 5/9 5/9
3. Approach
• Use 2 techniques to aid:
coded aperture + deconvolution
• Aperture filtermore information
PSF preserves
to improve deconvolution quality
[Rashkar 2006][Levin 2007][Veeraraghavan 2007]
• Deconvolution tousing natural image statistics
Recent advances
restore original image
[Bando 2007][Levin 2007]
4. Physical setup
• Rays from focused onto sensoraperture
plane and
scene pass through
• Cone of rays fromforming the shape of the
intersects sensor,
out-of-focus points
aperture
• A patternsensor aperture plane ispoints
onto the
in the
for out-of-focus
projected
5. Coded Aperture
• Originally from x-ray 1989]
[Fenimore 1978][Gottesman
astronomy
• Structured of pinhole, but better SNR with
resolution
arrays + decoding algorithm
• Employed in visible light photography
[Rashkar 2006][Levin 2007][Veeraraghavan 2007]
• Improve frequency properties of filter
6. Aperture filters
• What makes a good filter?
• Frequency response
• Position and spacing of zero frequencies
• Diffraction / transmission
7. Deconvolution
• Restore image distorted by PSF
[Wiener 1964][Richardson 1972][Lucy 1974]
f = f0 ⊗ k + η
• Ill-posed, infinite solutions
• No exact solution due to noise
• Division in FFT, issues with small
values in OTF of filter
8. Deconvolution
• Current state-of-the-art methods rely on natural
image statistics
• Real-worlddistribution of several properties:
Heavy-tail
images share
gradients
• Prior 2007][Levindeconvolution algorithms
[Bando
term in
2007]
• Favors interpretations fewthe image with all the
gradient intensity at a
of
pixels
9. Evaluation
• Goal : determine whether any combo of filterDR
deconvolution yields meaningful reduction in
/
with acceptable final image quality
• Measure DR reduction both in terms of image
local contrast and filter
• Measure image quality as images between
deconvolved and original
difference
10. Source material
Atrium Morning Atrium Night
Figure 3.3: Sample images used in evaluation.
Radius Atrium Morning Atrium Night
min max reduction min max reduction
Original 0.00 11.0 0.00 12.0
1 0.00 10.8 0.200 0.452 12.0 0.452
2 0.00 10.6 0.424 0.622 12.0 0.622
3 0.00 10.3 0.716 1.163 11.8 1.34
4 0.02 10.0 1.00 1.436 11.4 1.99
5 0.08 9.94 1.14 1.589 11.4 2.23
6 0.15 9.92 1.24 1.731 11.2 2.51
8 0.31 9.83 1.48 1.890 10.8 3.13
9 0.40 9.79 1.61 1.950 10.5 3.41
11 0.66 9.71 1.94 2.08 10.3 3.74
13 0.86 9.67 2.19 2.18 10.1 4.13
16 1.04 9.59 2.45 2.26 9.61 4.65
Figure 3.4: Amount of reduction in dynamic range as a function of radius of a standard aperture (disk)
filter in pixels. All units are in terms of powers of two, referred to as exposure value (EV) stops.
Atrium Morning Atrium Night
11. Source material
Atrium Morning Atrium Night
Figure 3.3: Sample images used in evaluation.
Radius Atrium Morning Atrium Night
min max reduction min max reduction
Original 0.00 11.0 0.00 12.0
1 0.00 10.8 0.200 0.452 12.0 0.452
2 0.00 10.6 0.424 0.622 12.0 0.622
3 0.00 10.3 0.716 1.163 11.8 1.34
4 0.02 10.0 1.00 1.436 11.4 1.99
5 0.08 9.94 1.14 1.589 11.4 2.23
6 0.15 9.92 1.24 1.731 11.2 2.51
8 0.31 9.83 1.48 1.890 10.8 3.13
9 0.40 9.79 1.61 1.950 10.5 3.41
11 0.66 9.71 1.94 2.08 10.3 3.74
13 0.86 9.67 2.19 2.18 10.1 4.13
16 1.04 9.59 2.45 2.26 9.61 4.65
2.45 EV
Figure 3.4: Amount of reduction in dynamic range as a function of radius of a standard aperture (disk)
filter in pixels. All units are in terms of powers of two, referred to as exposure value (EV) stops.
Atrium Morning Atrium Night
12. Source material
Atrium Morning Atrium Night
Figure 3.3: Sample images used in evaluation.
Radius Atrium Morning Atrium Night
min max reduction min max reduction
Original 0.00 11.0 0.00 12.0
1 0.00 10.8 0.200 0.452 12.0 0.452
2 0.00 10.6 0.424 0.622 12.0 0.622
3 0.00 10.3 0.716 1.163 11.8 1.34
4 0.02 10.0 1.00 1.436 11.4 1.99
5 0.08 9.94 1.14 1.589 11.4 2.23
6 0.15 9.92 1.24 1.731 11.2 2.51
8 0.31 9.83 1.48 1.890 10.8 3.13
9 0.40 9.79 1.61 1.950 10.5 3.41
11 0.66 9.71 1.94 2.08 10.3 3.74
13 0.86 9.67 2.19 2.18 10.1 4.13
16 1.04 9.59 2.45 2.26 9.61 4.65
2.45 EV 4.56 EV
Figure 3.4: Amount of reduction in dynamic range as a function of radius of a standard aperture (disk)
filter in pixels. All units are in terms of powers of two, referred to as exposure value (EV) stops.
Atrium Morning Atrium Night
13. Tests
• Filters evaluated: • Deconvolution evaluated:
• Normal aperture • Wiener filtering
• Gaussian • Richardson-Lucy
• Veeraraghavan • Bando
• Levin • Levin
• Zhou
14. Evaluation (cont)
• Success criteria:
• Reduction of computational cost of deconv
to justify the
at least 2 stops
• Quality of at least PSNR 35
22. Conclusions
• Levin deconv at very low noise levels with
coded filters
the best, obtaining results
• No combination of filter and deconvolution
consistently produced acceptable results
• Efficiency of the approach is scene dependent
Most efficient for small, isolated bright regions
Editor's Notes
Can be expanded by multiple exposures, new filter arrays, or better sensor tech
Blurring causes pixels to distribute energy over a local neighborhood
Reducing local contrast
Depending on image structure, can translate to reduction in global contrast
Images with small features: good
Images with large features: not good
Conv = FFT mult -> Deconv = FFT div -- properties of filter influence ability to deconvolve
Restore image convolved by a known function degraded by noise - Ill posed, numerous solutions
Real world images all share several properties - specifically the distribution of gradient intensity
Surfaces = large regions of flat intensity with sharp changes - mostly small changes but some very large
FFT of a conventional aperture is roughly a sinc function
Information loss
How well it preserves the information of the signal
Physical shape of pattern and whether it causes more diffraction
The more light it lets through the better
Heavy-tail = most values near zero, but a few with much high values
Narrower peak, and wider tail than a Gaussian
Results in sharper images with less noise and ringing
Blurring decreases local contrast
Image structure determines how much global contrast is reduced
Small features reduce more than large ones
CAN ONLY REDUCE CONTRAST OF FEATURES SMALLER THAN PSF DIAMETER
Done in simulation - evaluate best case
Change in dynamic range as each image is blurred by different filter radii
Size of bright and dark features affects how much dynamic range is reduced
Change in dynamic range as each image is blurred by different filter radii
Size of bright and dark features affects how much dynamic range is reduced
2 stops to justify computational cost -- Green area denotes acceptable by our criteria
Levin performs the best when there is no noise
Levin and Zhou perform best overall
Gaussian is worst - destroys too much information
Noise sensitivity of Weiner becomes apparent
Levin performs best in morning scene, RL wins out for night
Levin yields sharper results, but introduces more ringing - bright points ruin shadow detail
Levin and Zhou perform slightly better in the morning scene
All same in the night
Investigate deconvolution routines that are better able to handle the relative differences of HDR images