This document discusses the key parameters and sensitivity limits of various light detectors and imaging systems. It covers unintensified detectors like vidicons, CCD cameras, and photodiode arrays, as well as intensified detectors that use image intensifiers to amplify light signals and improve sensitivity. Cooled CCD systems are also described, which can achieve sensitivities as low as 10-10 lux through techniques like cooling to reduce dark current and slower readout rates to minimize readout noise.
CCTV, or closed-circuit television, is a technology that uses cameras to transmit video images to a specific place for monitoring and security purposes. The document discusses various types of CCTV cameras like dome cameras, bullet cameras, and their applications in areas like industries, crime prevention, and traffic monitoring. It also covers CCTV system components, types of lenses, image sensors, features like WDR, and considerations for camera selection and system design. Digital video recorders (DVRs) are also discussed which record video from CCTV cameras.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2021/10/building-the-eyes-of-a-vision-system-from-photons-to-bits-a-presentation-from-gopro/
Jon Stern, Director of Optical Systems at GoPro, presents the “Building the Eyes of a Vision System: From Photons to Bits” tutorial at the May 2021 Embedded Vision Summit.
In this tutorial, Stern presents a guide to the multidisciplinary science of building the eyes of a vision system. CMOS image sensors have been instrumental in lowering the barrier for embedding vision into systems. Their high degree of integration allows photons to be converted into bits with minimal support circuitry. Simple protocols and interfaces mean that companies can design camera-based systems with comparatively little specialist expertise.
To produce high-quality output, the image sensor and optics must be carefully co-optimized to fit the application. To assist with component selection and help avoid common pitfalls, Stern describes the key parameters and provides a practical guide to selecting both sensor and optics for a camera. He also provides an introduction to other hardware considerations and to correcting optical aberrations in the image processing pipeline.
1) Fluoroscopy uses pulsed or continuous X-rays and a video camera system to generate real-time moving images of the internal structures of the body.
2) Early fluoroscopy used image intensifiers to convert X-rays to visible light images, while modern digital fluoroscopy uses flat panel detectors and pulse-progressive fluoroscopy to acquire images.
3) Automatic brightness control and magnification allow fluoroscopy units to maintain image brightness and zoom in on areas of interest, while advances in digital technology provide faster imaging, image storage, and lower radiation doses.
This document discusses projection systems and their interfacing. It describes the key components and specifications of three main projection technologies: CRT, LCD, and DLP. CRT projectors use a cathode ray tube to generate images while LCD uses liquid crystal displays and DLP (digital light processing) uses a digital micromirror device chip. The document outlines specifications for each like brightness, resolution, throw ratio and inputs/outputs including VGA and HDMI interfaces.
This document provides an overview of computed radiography (CR) and digital radiography (DR). CR uses an imaging plate that captures x-ray data, which is then processed to produce digital images. DR directly converts x-rays to digital signals using detectors like selenium or scintillator crystals. Both produce digital images but DR has higher image quality and requires less time as there is no imaging plate development step. While DR systems have higher costs, the digital format allows for improved image processing and long-term storage compared to conventional radiography.
As we enter in the Modern day, we are witnessing dawn of the new trend in which closed body operating procedures are more often being performed through minimal access. This development is the consequence of vision and work of many dedicated individuals. They include early pioneers of endoscopy who planted the seed and lastly the current pioneers who pushed and expanded these frontiers to give rise the birth of modern laparoscopy. Therapeutic laparoscopic surgery was introduced into the surgical practice recently and within a short span of time, it has become established as defacto standard for the treatment of chronic cholelithiasis and many advanced laparoscopic procedures can be performed safely. Laparoscopic surgery, what we should witness today, may be the culmination of over a hundred years of painstaking efforts from the number of pioneers within the fields of optics, instrumentation and video laparoscopic camera. Few advances in medicine occur in isolation. The innate human curiosity to peer within the body cavities can be traced back to ancient times. However, due to primitive technology and crude instruments, several ambitions were not realized. It is probably safe to say that first laparoscopy would not have been performed had it not been for the efforts of many physicians in 1800s to develop endoscope. The device developed by Theodore Stein in mid 1880 contains all the aspects of the current endoscopic documentation system. There was a crude endoscope and a high intensity light source. Illumination was made by continuously feeding a magnesium wire into an ignition chamber utilizing a clockwise mechanism. Light from this combustion was reflected to the tube utilizing a mirror. Finally the look was focused on to some photographic plate through coupling optics.
Digital imaging involves capturing radiographic images digitally using various methods like computed radiography (CR), direct radiography (DR), or scan projection radiography (SPR). CR uses photostimulable phosphor plates while DR uses flat panel detectors, eliminating processing. Digital imaging provides advantages like improved image manipulation, reduced radiation exposure, and improved storage and sharing of images. Key types of digital radiography discussed are CR, DR, SPR, digital fluoroscopy, and digital subtraction angiography (DSA).
CCTV, or closed-circuit television, is a technology that uses cameras to transmit video images to a specific place for monitoring and security purposes. The document discusses various types of CCTV cameras like dome cameras, bullet cameras, and their applications in areas like industries, crime prevention, and traffic monitoring. It also covers CCTV system components, types of lenses, image sensors, features like WDR, and considerations for camera selection and system design. Digital video recorders (DVRs) are also discussed which record video from CCTV cameras.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2021/10/building-the-eyes-of-a-vision-system-from-photons-to-bits-a-presentation-from-gopro/
Jon Stern, Director of Optical Systems at GoPro, presents the “Building the Eyes of a Vision System: From Photons to Bits” tutorial at the May 2021 Embedded Vision Summit.
In this tutorial, Stern presents a guide to the multidisciplinary science of building the eyes of a vision system. CMOS image sensors have been instrumental in lowering the barrier for embedding vision into systems. Their high degree of integration allows photons to be converted into bits with minimal support circuitry. Simple protocols and interfaces mean that companies can design camera-based systems with comparatively little specialist expertise.
To produce high-quality output, the image sensor and optics must be carefully co-optimized to fit the application. To assist with component selection and help avoid common pitfalls, Stern describes the key parameters and provides a practical guide to selecting both sensor and optics for a camera. He also provides an introduction to other hardware considerations and to correcting optical aberrations in the image processing pipeline.
1) Fluoroscopy uses pulsed or continuous X-rays and a video camera system to generate real-time moving images of the internal structures of the body.
2) Early fluoroscopy used image intensifiers to convert X-rays to visible light images, while modern digital fluoroscopy uses flat panel detectors and pulse-progressive fluoroscopy to acquire images.
3) Automatic brightness control and magnification allow fluoroscopy units to maintain image brightness and zoom in on areas of interest, while advances in digital technology provide faster imaging, image storage, and lower radiation doses.
This document discusses projection systems and their interfacing. It describes the key components and specifications of three main projection technologies: CRT, LCD, and DLP. CRT projectors use a cathode ray tube to generate images while LCD uses liquid crystal displays and DLP (digital light processing) uses a digital micromirror device chip. The document outlines specifications for each like brightness, resolution, throw ratio and inputs/outputs including VGA and HDMI interfaces.
This document provides an overview of computed radiography (CR) and digital radiography (DR). CR uses an imaging plate that captures x-ray data, which is then processed to produce digital images. DR directly converts x-rays to digital signals using detectors like selenium or scintillator crystals. Both produce digital images but DR has higher image quality and requires less time as there is no imaging plate development step. While DR systems have higher costs, the digital format allows for improved image processing and long-term storage compared to conventional radiography.
As we enter in the Modern day, we are witnessing dawn of the new trend in which closed body operating procedures are more often being performed through minimal access. This development is the consequence of vision and work of many dedicated individuals. They include early pioneers of endoscopy who planted the seed and lastly the current pioneers who pushed and expanded these frontiers to give rise the birth of modern laparoscopy. Therapeutic laparoscopic surgery was introduced into the surgical practice recently and within a short span of time, it has become established as defacto standard for the treatment of chronic cholelithiasis and many advanced laparoscopic procedures can be performed safely. Laparoscopic surgery, what we should witness today, may be the culmination of over a hundred years of painstaking efforts from the number of pioneers within the fields of optics, instrumentation and video laparoscopic camera. Few advances in medicine occur in isolation. The innate human curiosity to peer within the body cavities can be traced back to ancient times. However, due to primitive technology and crude instruments, several ambitions were not realized. It is probably safe to say that first laparoscopy would not have been performed had it not been for the efforts of many physicians in 1800s to develop endoscope. The device developed by Theodore Stein in mid 1880 contains all the aspects of the current endoscopic documentation system. There was a crude endoscope and a high intensity light source. Illumination was made by continuously feeding a magnesium wire into an ignition chamber utilizing a clockwise mechanism. Light from this combustion was reflected to the tube utilizing a mirror. Finally the look was focused on to some photographic plate through coupling optics.
Digital imaging involves capturing radiographic images digitally using various methods like computed radiography (CR), direct radiography (DR), or scan projection radiography (SPR). CR uses photostimulable phosphor plates while DR uses flat panel detectors, eliminating processing. Digital imaging provides advantages like improved image manipulation, reduced radiation exposure, and improved storage and sharing of images. Key types of digital radiography discussed are CR, DR, SPR, digital fluoroscopy, and digital subtraction angiography (DSA).
Specific innovative semi-transparent solar cell for indoor and outdoor LiFi a...Nam Yong Kim
This document discusses using semi-transparent solar cells as light-fidelity (LiFi) receivers. Two types of solar cells were tested - a copper indium gallium selenide (CIGS) module and an amorphous silicon (a-Si) module. Testing showed the CIGS module performed better for weak LiFi signals, while the a-Si module could receive high LiFi signals up to 270,000 lux. Additionally, the a-Si module's signal-to-noise ratio (SNR) and data rate increased with ambient lighting levels, an unexpected result that makes it suitable for combined indoor and outdoor LiFi applications.
Video display devices use various technologies to visually present electronic information. Common types include CRT, LCD, LED, and plasma displays. CRTs use an electron gun to excite phosphors on the screen and were widely used in monitors and TVs. They can operate in raster or random scan modes. Color CRTs use shadow mask or beam penetration methods. Flat panel displays like LCDs are thinner than CRTs and use light modulation rather than emission to display images.
The document discusses image sensors and compares CCD and CMOS sensor technologies. It describes how image sensors work by converting light into electrical signals and digital data. CCD sensors were once dominant but CMOS sensors now provide faster readouts and are less expensive to manufacture, though they can cause issues like skew and partial exposure. The document examines key attributes of image sensors like resolution, frame rate, power consumption, and dynamic range that are important for applications in consumer cameras, medical imaging, and surveillance. Choosing the best sensor requires weighing these various attributes against the needs of the specific application.
Viewing and recording the fluoroscopic imageSHASHI BHUSHAN
The document describes the process of viewing and recording intensified fluoroscopic images. It discusses how an image intensifier converts visual light images into electrical signals that are then viewed on a video monitor or recorded. Recording can be done using spot film cameras, cinefluoroscopy movie cameras, or by recording the video signal from the television camera onto magnetic tape, discs, or optical discs. The television camera converts the light image back into an electrical video signal for viewing, storage, or transmission to other viewing locations.
CCDs are light-sensitive integrated circuits used in digital cameras and video cameras to convert light into electrical charges. Each pixel on the CCD sensor converts incoming photons into an electrical charge proportional to light intensity. During image capture, the charges are transferred and read out to form a digital image. CCDs have advantages like high sensitivity and no need for chemical processing, but also disadvantages like higher power consumption and manufacturing costs compared to other sensors.
The document discusses digital radiography, including computed radiography (CR) and direct radiography using flat panel detectors. It summarizes the limitations of conventional film-based radiography and then describes the key components and workings of CR and direct digital radiography systems. Some advantages include improved image quality, ability to manipulate images digitally, faster processing, and reduced need for retakes compared to conventional methods.
Digital imaging with charge coupled devicesSteven Shaw
The document discusses capacitance and how charge accumulates on parallel plates when a potential difference is applied. It then summarizes how charge-coupled devices (CCDs) work, noting that each pixel acts as a small capacitor that releases electrons proportional to the intensity of light hitting it. The charges are transferred to a register and converted to a digital image. Key characteristics of CCDs discussed include quantum efficiency, magnification, and resolution. Medical uses of CCDs in endoscopy and X-ray detection are also summarized.
This document provides information about various camera settings and technologies for capturing clear images, including:
1. Clear Scan helps eliminate banding caused when a camera's frame rate does not match a CRT display's refresh rate.
2. Slow Shutter extends the camera's exposure time to produce blur effects or allow more light in low-light scenes.
3. Super Sampling uses a 1080p camera to produce sharper 720p images by maintaining higher frequency response.
4. Detail correction adds a spike-shaped detail signal to make edges appear sharper without degrading resolution. Settings like detail level and H/V ratio control the amount and balance of detail correction.
5. Other topics covered
Digital radiography has replaced conventional screen-film radiography since the mid-1980s. There are two main types of digital receptors: solid-state detectors like CCD and CMOS sensors, and photostimulable phosphor plates. Solid-state detectors directly convert x-rays to an electrical signal while photostimulable phosphor plates store the x-ray energy and then release it as light during the scanning process. Digital images allow for features like contrast resolution, spatial resolution, latitude, and sensitivity. They can be viewed on screens and printed. Image processing can also enhance digital images.
CCD cameras use charge-coupled device sensors to capture images as video signals. The document explains how CCD cameras work, focusing on the operation of the CCD imager chip at the heart of the camera. It describes how light is converted to electrical charge in sensor cells arranged in arrays, and how the charges are transferred and converted to a video signal. It provides information on camera resolution, spectral response, power requirements and other specifications to help select an appropriate camera.
The document discusses different types of digital camera image sensors including CCD, CMOS, and full frame sensors. It explains key sensor specifications like resolution, pixel size, and crop factor which is the ratio of a sensor's diagonal size compared to a full frame 35mm sensor. A larger crop factor means a smaller sensor that crops the image circle of a lens, but can have advantages for lens sharpness by discarding lower quality edge areas.
Digital fluoroscopy uses a digital x-ray system to create dynamic images using an area x-ray beam. The main difference from conventional fluoroscopy is that images are digitized. It uses pulsed progressive fluoroscopy with short exposures to reduce patient dose while maintaining image quality. Images are detected using a charge-coupled device (CCD) instead of a TV camera, offering benefits like higher resolution, sensitivity, and stability. Flat panel detectors composed of cesium iodide and amorphous silicon pixels provide a more uniform, higher quality image than traditional image intensifiers. Overall, digital fluoroscopy improves image quality and lowers patient radiation exposure.
Different types of imaging devices and principles.pptxAayushiPaul1
Digital radiography uses digital image receptors instead of film. Large digital radiographic images require significant storage space, network bandwidth, and high-resolution monitors. Picture archiving and communication systems (PACS) provide economical storage and access to medical images across systems using DICOM standards. Common digital x-ray technologies include computed radiography, direct radiography using CCDs or flat panel detectors, and direct detection flat panel systems which directly convert x-rays to electron-hole pairs.
1. Fluoroscopy uses real-time x-ray imaging to view internal body structures. X-ray photons hit an input phosphor, releasing light photons that trigger photoelectrons which are focused onto an output screen, intensifying the image.
2. Modern fluoroscopy uses flat panel detectors instead of image intensifiers. This provides digital images without distortion and allows techniques like digital filtering to enhance images while reducing radiation dose.
3. Equipment is configured for different clinical needs but always aims to minimize scatter radiation and dose while maintaining diagnostic image quality.
High speed cameras can capture events at over 1,000 frames per second, allowing finer details to be seen when played back at normal speed. They focus light onto an image sensor, converting the image into an electronic format. The document discusses the high speed camera available in the author's lab and its uses, including combustion research, microfluidics, and sports broadcasts. It also covers aperture, depth of field, CCD and CMOS image sensors used in high speed cameras.
This document provides an overview of analog and digital data transmission and optical fibers. It discusses how analog signals carry data continuously while digital signals carry data in discrete pulses. It also explains the advantages of digital transmission such as noise immunity, multiplexing capability, and ability to detect errors. The document then describes how optical fibers transmit data using total internal reflection and their construction. It discusses the types of optical fibers and their properties. Finally, it outlines the advantages and applications of optical fibers, including their high bandwidth, low loss, immunity to interference, flexibility and secure transmission.
Computed radiography and digital radiography are two methods for obtaining digital x-rays. Computed radiography uses an imaging plate inside a cassette that captures x-rays, which are then digitized in a CR reader. Digital radiography uses a flat panel detector with either direct or indirect conversion of x-rays to electrical signals. Both methods provide advantages over conventional film such as faster workflow, ability to adjust images after exposure, and reduced radiation dose for patients.
author: Dr.Hasan A.Ali
content:
introduction
terminology
- advantages and disadvantages
- types of digital radiography
- types of sensors
- uses of computer in digital imaging
- other features of digital imaging
compiter radiography and digital radiography Unaiz Musthafa
This document discusses computed radiography (CR) and digital radiography (DR). CR uses reusable imaging plates instead of film, which are read by a laser scanner. DR uses a digital detector incorporated into x-ray equipment to provide direct digital output. Both have greater exposure latitude than screen-film and allow computer post-processing to enhance images. Technologists must monitor exposure indices to avoid overexposure with CR and DR systems. The document also covers digital fluoroscopy techniques like frame averaging.
Specific innovative semi-transparent solar cell for indoor and outdoor LiFi a...Nam Yong Kim
This document discusses using semi-transparent solar cells as light-fidelity (LiFi) receivers. Two types of solar cells were tested - a copper indium gallium selenide (CIGS) module and an amorphous silicon (a-Si) module. Testing showed the CIGS module performed better for weak LiFi signals, while the a-Si module could receive high LiFi signals up to 270,000 lux. Additionally, the a-Si module's signal-to-noise ratio (SNR) and data rate increased with ambient lighting levels, an unexpected result that makes it suitable for combined indoor and outdoor LiFi applications.
Video display devices use various technologies to visually present electronic information. Common types include CRT, LCD, LED, and plasma displays. CRTs use an electron gun to excite phosphors on the screen and were widely used in monitors and TVs. They can operate in raster or random scan modes. Color CRTs use shadow mask or beam penetration methods. Flat panel displays like LCDs are thinner than CRTs and use light modulation rather than emission to display images.
The document discusses image sensors and compares CCD and CMOS sensor technologies. It describes how image sensors work by converting light into electrical signals and digital data. CCD sensors were once dominant but CMOS sensors now provide faster readouts and are less expensive to manufacture, though they can cause issues like skew and partial exposure. The document examines key attributes of image sensors like resolution, frame rate, power consumption, and dynamic range that are important for applications in consumer cameras, medical imaging, and surveillance. Choosing the best sensor requires weighing these various attributes against the needs of the specific application.
Viewing and recording the fluoroscopic imageSHASHI BHUSHAN
The document describes the process of viewing and recording intensified fluoroscopic images. It discusses how an image intensifier converts visual light images into electrical signals that are then viewed on a video monitor or recorded. Recording can be done using spot film cameras, cinefluoroscopy movie cameras, or by recording the video signal from the television camera onto magnetic tape, discs, or optical discs. The television camera converts the light image back into an electrical video signal for viewing, storage, or transmission to other viewing locations.
CCDs are light-sensitive integrated circuits used in digital cameras and video cameras to convert light into electrical charges. Each pixel on the CCD sensor converts incoming photons into an electrical charge proportional to light intensity. During image capture, the charges are transferred and read out to form a digital image. CCDs have advantages like high sensitivity and no need for chemical processing, but also disadvantages like higher power consumption and manufacturing costs compared to other sensors.
The document discusses digital radiography, including computed radiography (CR) and direct radiography using flat panel detectors. It summarizes the limitations of conventional film-based radiography and then describes the key components and workings of CR and direct digital radiography systems. Some advantages include improved image quality, ability to manipulate images digitally, faster processing, and reduced need for retakes compared to conventional methods.
Digital imaging with charge coupled devicesSteven Shaw
The document discusses capacitance and how charge accumulates on parallel plates when a potential difference is applied. It then summarizes how charge-coupled devices (CCDs) work, noting that each pixel acts as a small capacitor that releases electrons proportional to the intensity of light hitting it. The charges are transferred to a register and converted to a digital image. Key characteristics of CCDs discussed include quantum efficiency, magnification, and resolution. Medical uses of CCDs in endoscopy and X-ray detection are also summarized.
This document provides information about various camera settings and technologies for capturing clear images, including:
1. Clear Scan helps eliminate banding caused when a camera's frame rate does not match a CRT display's refresh rate.
2. Slow Shutter extends the camera's exposure time to produce blur effects or allow more light in low-light scenes.
3. Super Sampling uses a 1080p camera to produce sharper 720p images by maintaining higher frequency response.
4. Detail correction adds a spike-shaped detail signal to make edges appear sharper without degrading resolution. Settings like detail level and H/V ratio control the amount and balance of detail correction.
5. Other topics covered
Digital radiography has replaced conventional screen-film radiography since the mid-1980s. There are two main types of digital receptors: solid-state detectors like CCD and CMOS sensors, and photostimulable phosphor plates. Solid-state detectors directly convert x-rays to an electrical signal while photostimulable phosphor plates store the x-ray energy and then release it as light during the scanning process. Digital images allow for features like contrast resolution, spatial resolution, latitude, and sensitivity. They can be viewed on screens and printed. Image processing can also enhance digital images.
CCD cameras use charge-coupled device sensors to capture images as video signals. The document explains how CCD cameras work, focusing on the operation of the CCD imager chip at the heart of the camera. It describes how light is converted to electrical charge in sensor cells arranged in arrays, and how the charges are transferred and converted to a video signal. It provides information on camera resolution, spectral response, power requirements and other specifications to help select an appropriate camera.
The document discusses different types of digital camera image sensors including CCD, CMOS, and full frame sensors. It explains key sensor specifications like resolution, pixel size, and crop factor which is the ratio of a sensor's diagonal size compared to a full frame 35mm sensor. A larger crop factor means a smaller sensor that crops the image circle of a lens, but can have advantages for lens sharpness by discarding lower quality edge areas.
Digital fluoroscopy uses a digital x-ray system to create dynamic images using an area x-ray beam. The main difference from conventional fluoroscopy is that images are digitized. It uses pulsed progressive fluoroscopy with short exposures to reduce patient dose while maintaining image quality. Images are detected using a charge-coupled device (CCD) instead of a TV camera, offering benefits like higher resolution, sensitivity, and stability. Flat panel detectors composed of cesium iodide and amorphous silicon pixels provide a more uniform, higher quality image than traditional image intensifiers. Overall, digital fluoroscopy improves image quality and lowers patient radiation exposure.
Different types of imaging devices and principles.pptxAayushiPaul1
Digital radiography uses digital image receptors instead of film. Large digital radiographic images require significant storage space, network bandwidth, and high-resolution monitors. Picture archiving and communication systems (PACS) provide economical storage and access to medical images across systems using DICOM standards. Common digital x-ray technologies include computed radiography, direct radiography using CCDs or flat panel detectors, and direct detection flat panel systems which directly convert x-rays to electron-hole pairs.
1. Fluoroscopy uses real-time x-ray imaging to view internal body structures. X-ray photons hit an input phosphor, releasing light photons that trigger photoelectrons which are focused onto an output screen, intensifying the image.
2. Modern fluoroscopy uses flat panel detectors instead of image intensifiers. This provides digital images without distortion and allows techniques like digital filtering to enhance images while reducing radiation dose.
3. Equipment is configured for different clinical needs but always aims to minimize scatter radiation and dose while maintaining diagnostic image quality.
High speed cameras can capture events at over 1,000 frames per second, allowing finer details to be seen when played back at normal speed. They focus light onto an image sensor, converting the image into an electronic format. The document discusses the high speed camera available in the author's lab and its uses, including combustion research, microfluidics, and sports broadcasts. It also covers aperture, depth of field, CCD and CMOS image sensors used in high speed cameras.
This document provides an overview of analog and digital data transmission and optical fibers. It discusses how analog signals carry data continuously while digital signals carry data in discrete pulses. It also explains the advantages of digital transmission such as noise immunity, multiplexing capability, and ability to detect errors. The document then describes how optical fibers transmit data using total internal reflection and their construction. It discusses the types of optical fibers and their properties. Finally, it outlines the advantages and applications of optical fibers, including their high bandwidth, low loss, immunity to interference, flexibility and secure transmission.
Computed radiography and digital radiography are two methods for obtaining digital x-rays. Computed radiography uses an imaging plate inside a cassette that captures x-rays, which are then digitized in a CR reader. Digital radiography uses a flat panel detector with either direct or indirect conversion of x-rays to electrical signals. Both methods provide advantages over conventional film such as faster workflow, ability to adjust images after exposure, and reduced radiation dose for patients.
author: Dr.Hasan A.Ali
content:
introduction
terminology
- advantages and disadvantages
- types of digital radiography
- types of sensors
- uses of computer in digital imaging
- other features of digital imaging
compiter radiography and digital radiography Unaiz Musthafa
This document discusses computed radiography (CR) and digital radiography (DR). CR uses reusable imaging plates instead of film, which are read by a laser scanner. DR uses a digital detector incorporated into x-ray equipment to provide direct digital output. Both have greater exposure latitude than screen-film and allow computer post-processing to enhance images. Technologists must monitor exposure indices to avoid overexposure with CR and DR systems. The document also covers digital fluoroscopy techniques like frame averaging.
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
Literature Review Basics and Understanding Reference Management.pptx
Train.pptx
1. Introduction
• All imaging systems are characterized by a few simple
parameters:
1. Size of the sensitive area
2. Number of picture elements (pixels)
3. The range of light levels that the detector can work with.
• There is always a high light level above which the
detector is saturated and a low light level below which a
useful image cannot be obtained.
• Domestic TV cameras have their sensitivity defined in
terms of the lux.
• For quantitative work the lux is a very unsatisfactory unit
since it is defined with a broad spectrum light source.
2. Introduction (Contd.)
• Very roughly, low cost monochrome TV
cameras that use CCDs are often able to
work down to 0.1 lux or better.
• This corresponds to photon arrival rates of
about 1010 photons/second/mm2.
• Color CCD cameras have sensitivity limits
in the region of 10 lux, which are very high
light levels.
4. Unintensified Imaging Detectors
1-Unintensified Vidicons
• These are a form of TV camera tube where the image that
falls on the target progressively discharges the target.
• A scanned electron beam recharges the target each time
the image is ‘read out’.
• The resolution of vidicons is generally poor.
• In addition, the target recharging mechanism is highly non-
linear, so it is difficult to use vidicons for accurate
photometric work.
• The low light level sensitivity limit is set by internally
generated noise sources which occur even in the absence
of an input signal (dark current and read-out noise).
• This limits vidicon sensitivity to around 10-3 lux at best.
5. 2- Unintensified CCD TV cameras
• They consist of a slice of silicon that absorbs photons and directly
generates a charge (one electron per absorbed photon).
• The generated charges are held in place by an array of electrodes
and the signal is read out by transferring the charge in each pixel to
the device output, one pixel at a time.
• At low signal level the performance of a CCD TV camera is limited by
the internally generated dark current and by the noise generated in
the first stage signal amplifier that is built as part of the CCD chip.
• The best monochrome CCD TV cameras will work down to 10-3 lux.
The CCD response is highly linear, although CCD cameras are often
designed with an intentional electronic non-linearity that gives a
cosmetically more appealing picture on a TV monitor.
• Their resolution is largely set by the pixel size and their sensitivity is
very high.
• By virtue of being solid state integrated circuits they are rugged and
highly resistant to damage from light overload.
6. 3- Unintensified Photodiode Arrays
• They are generally one-dimensional devices, often
with long, thin pixels (2.5 mm by 25 microns is
common).
• They have similar advantages to CCDs in that they
are solid state devices and are therefore rugged.
• The large area of their pixels gives a high dark
current at room temperatures.
• Even if the device is cooled and in the absence of
signal or dark current, the readout structure
generates a rather high readout noise.
7. Intensified Imaging Detectors
• In trying to achieve low light level performance with any of
the above systems we find we are limited by sources of
noise that are generated internally by the detector itself.
• If we can amplify the signal we wish to detect and couple
that intensified signal to the detector then we should be able
to work at lower light levels.
• This can be achieved by an image intensifier which is
placed in front of the detector and consists of a
photocathode which emits many photons or electrons for
each incident photon.
• Image intensifiers produce an improvement in sensitivity
which can be as high as a factor of 1000, or even more.
• However, the intensifiers have a number of consequences
on the overall performance of the system.
8. Intensifiers Consequences on System Performance
1. The light detection efficiency of the photocathode is often poorer
than that of the detector to which it is coupled.
2. The overall luminous gain of the intensifier plus the image
coupling to the detector has to be carefully selected so that no
saturation will result for relatively low input signal.
3. An intensifier reduces the dynamic range of the detector (the ratio
of the strongest detectable signal to the weakest detectable
signal in a single image)
4. With all intensifiers there is a lot of signal-induced background
which limits the dynamic range to a level that can be as low as
100:1.
• Clearly these effects reduce the overall imaging quality of the
system, and imperfections in the intensifier itself (photocathode
non-uniformities, geometric distortions and resolution) will be
added to those inherent in the unintensified detector.
• However, intensifiers are generally capable of making much
lower light levels accessible to the scientist, albeit at a
considerable increase in overall system cost.
9. 1- Intensified Vidicons
• The most commonly used intensified vidicon is the Silicon
Intensified Target (SIT) vidicon which encapsulates a single
stage intensifier inside the vacuum envelope of a standard
vidicon.
• This gives a signal gain of about 2000 and allows work
down to 10-4 lux.
• As with all vidicons the linearity is poor.
• The resolution is reduced although it is possible to
purchase units with fairly high resolution.
• Further improvements in sensitivity are possible by gating
off the readout for several frames while letting the stored
image integrate up before reading it out.
• This cannot be used too much as the intensifier
photocathode itself suffers from dark current which limits
the sensitivity that may be achieved.
10. 2- Intensified CCD TV cameras
• As with the SIT camera, adding an intensifier
to a standard CCD TV camera gives a great
improvement in low light level sensitivity and
levels of 10-5 lux may be achieved with
careful component selection.
• As with the SIT camera the intensifier has
lower detection efficiency (photocathode
rather than silicon) and both resolution and
dynamic range are degraded.
11. 3- Intensified photodiode array
• Use of a high gain image intensifier allows
the high readout noise of the unintensified
photodiode array (PDA) to be overcome.
• Intensified PDAs are widely used for
spectroscopic applications where the
importance of the gain in sensitivity more
than offsets the lower detection efficiency
and poorer resolution of the system.
12. Video Signal Handling
• Both vidicons and CCD TV cameras (intensified or not)
produce standard video output signals.
• These consist of 525 or 625 lines of picture information
every 30 or 40 milliseconds.
• They have a big advantage in that image changes such as
motion may be displayed immediately on a standard TV
monitor.
• Computer cards known as frame grabbers allow a single TV
frame or a sequence of frames to be digitized and passed to
the computer software analysis package.
• This has several consequences:
• The high pixel rate (up to 10 MHz) means that the digitizing
is usually done to no more than 8 bits (256 levels)·
• The fast readout is often a source of noise limiting the useful
range of the data.
13. Video Signal Handling (Contd.)
• One method of improving the signal to noise that can be
achieved from a single video frame is to use a frame
grabber that allows a series of consecutive frames to be
co-added and averaged.
• However, most TV cameras are manufactured so that for
single frame operation the camera performs well. As
soon as many frames are averaged the summed image
can show other fixed pattern noise that cannot be
suppressed by averaging.
• Frame averaging will only work if truly random noise
limits the performance of the system. Video-rate
cameras usually suffer from many other noise sources
and these are not improved by frame-averaging.
14. Cooled CCD Systems
• The CCD is clearly attractive as an imaging detector
because it is rugged, compact, has good resolution,
excellent linearity and high detection efficiency.
• By cooling the CCD, by slowing down the read-out of the
CCD and by breaking free from the restrictions of TV
output format (analogue video signals), a much better
noise performance can be achieved, higher resolution
images can be obtained and dramatic sensitivity
improvements are possible, albeit at a longer cycle time
between images.
• This approach to achieving very low light level sensitivity
without using an image intensifier was originally
developed for astronomy.
15. Cooled CCD Systems
• At room temperatures, standard CCD TV cameras generate a dark
current that is very high - often hundreds or thousands of electrons
per pixel per second is typical.
• If the CCD is cooled, the dark current reduces roughly by a factor of
10 for every 20oC. Typical figures are 10 electrons per pixel per
second at -40oC, and less than one electron per pixel per hour at -
140oC.
• The next barrier to achieving very low light level performance is the
noise that is generated when the CCD is read out at video rates (i.e.
pixel rates of several megahertz).
• If the readout rate is reduced it becomes possible to use special
electronic signal processing procedures (called double correlated
sampling) to give a read-out noise of only a few electrons.
• This can to be compared with a read-out noise often several
hundred times higher at TV read-out rates.
• The net effect of using cooled CCDs and slower read-out rates is
that it is possible to achieve limiting sensitivities of 10-10 lux and
below at full image resolution.