DOCSLIB.ORG

IMAGE SENSORS and SIGNAL PROCESSING for DIGITAL STILL CAMERAS

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
IMAGE SENSORS and SIGNAL PROCESSING for DIGITAL STILL CAMERAS IMAGE SENSORS and SIGNAL PROCESSING for DIGITAL STILL CAMERAS Edited by Junichi Nakamura Boca Raton London New York Singapore A CRC title, part of the Taylor & Francis imprint, a member of the Taylor & Francis Group, the academic division of T&F Informa plc. Copyright © 2006 Taylor & Francis Group, LLC DK545X_Discl.fm Page 1 Friday, June 24, 2005 12:47 PM Published in 2006 by CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2006 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group No claim to original U.S. Government works Printed in the United States of America on acid-free paper 10 987654321 International Standard Book Number-10: 0-8493-3545-0 (Hardcover) International Standard Book Number-13: 978-0-8493-3545-7 (Hardcover) Library of Congress Card Number 2005041776 This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC) 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Library of Congress Cataloging-in-Publication Data Image sensors and signal processing for digital still cameras / edited by Junichi Nakamura. p. cm. Includes bibliographical references and index. ISBN 0-8493-3545-0 (alk. paper) 1. Image processing—Digital techniques. 2. Signal processing—Digital techniques. 3. Digital cameras. I. Nakamura, Junichi. TA1637.1448 2005 681'.418—dc22 2005041776 Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com Taylor & Francis Group and the CRC Press Web site at is the Academic Division of T&F Informa plc. http://www.crcpress.com Copyright © 2006 Taylor & Francis Group, LLC DK545X_C000.fm Page 5 Wednesday, July 6, 2005 8:12 AM Preface Since the introduction of the first consumer digital camera in 1995, the digital still camera (DSC) market has grown rapidly. The first DSC used a charge-coupled device (CCD) image sensor that had only 250,000 pixels. Ten years later, several models of consumer point-and-shoot DSCs with 8 million pixels are available, and profes- sional digital single-lens reflex (DSLR) cameras are available with 17 million pixels. Unlike video camera applications in which the output is intended for a TV monitor and, thus, the vertical resolution of the image sensors is standardized, there is no standard output or resolution for DSCs, so the sensor pixel count continues to grow. Continuing improvements in sensor technology have allowed this ever increasing number of pixels to be fit onto smaller and smaller sensors until pixels measuring just 2.3 mm ¥ 2.3 mm are now available in consumer cameras. Even with this dramatic shrinking of pixels, the sensitivity of sensors has improved to the point that shirt- pocket-sized consumer DSCs take good quality pictures with the exposure values equivalent to 400 ISO film. Improvements in optics and electronics technologies have also been remarkable. As a result, the image quality of pictures taken by a DSC has become comparable to that normally expected of silver-halide film cameras. Consistent with these improvements in performance, the market for DSCs has grown to the point that shipments of DSCs in 2003 surpassed those of film cameras. Image Sensors and Signal Processing for Digital Still Cameras focuses on image acquisition and signal-processing technologies in DSCs. From the perspective of the flow of the image information, a DSC consists of imaging optics, an image sensor, and a signal-processing block that receives a signal from the image sensor and generates digital data that are eventually compressed and stored on a memory device in the DSC. The image acquisition part of that flow includes the optics, the sensor, and front-end section of the signal-processing block that transforms photons into digital bits. The remainder of the signal-processing block is responsible for gener- ating the image data stored on the memory device. Other technologies used in a DSC, such as mechanics, data compression, user interface, and the output-processing block that provides the signals to output devices, such as an LCD, a TV monitor, a printer, etc., are beyond the scope of this book. Graduate students in electronics engineering and engineers working on DSCs should find this book especially valuable. However, I believe it offers interesting reading for technical professionals in the image sensor and signal-processing fields as well. The book consists of 11 chapters: •Chapter 1, “Digital Still Cameras at a Glance,” introduces the historical background and current status of DSCs. Readers will be able to understand Copyright © 2006 Taylor & Francis Group, LLC DK545X_C000.fm Page 6 Wednesday, July 6, 2005 8:12 AM what DSCs are, how they have evolved, types of modern DSCs, their basic structure, and their applications. •In Chapter 2, “Optics in Digital Still Cameras,” a wide range of topics explains the imaging optics used in DSCs. It is obvious that high image quality cannot be obtained without a high-performance imaging optical system. It is also true that requirements for imaging optics have become higher as pixel counts have increased and pixel sizes have decreased. •Reviews of image sensor technologies for DSC applications can be found in Chapter 3 through Chapter 6. •First, in Chapter 3, “Basics of Image Sensors,” the functions and performance parameters common to CCD and complementary metal- oxide semiconductor (CMOS) image sensors are explained. •Chapter 4, “CCD Image Sensors,” describes in detail the CCD image sensors widely used in imaging applications. The chapter ranges from a discussion of basic CCD operating principles to descriptions of CCD image sensors specifically designed for DSC applications. •Chapter 5, “CMOS Image Sensors,” discusses the relatively new CMOS image sensor technology, whose predecessor, the MOS type of image sensor, was released into the market almost 40 years ago, even before the CCD image sensor. •Following these descriptions of image sensors, methods for evaluating image sensor performances relative to DSC requirements are presented in Chapter 6, “Evaluation of Image Sensors.” •Chapter 7 and Chapter 8 provide the basic knowledge needed to imple- ment image processing algorithms. •The topics discussed in Chapter 7, “Color Theory and Its Application to Digital Still Cameras,” could easily fill an entire book; however, the emphasis here is on how color theory affects the practical uses of DSC applications. •Chapter 8, “Image-Processing Algorithms,” presents the algorithms utilized by the software or hardware in a DSC. Basic image-processing and camera control algorithms are provided along with advanced image-processing examples. •This provides the framework for the description of the image-processing hardware engine in Chapter 9, “Image-Processing Engines.” The required performance parameters for DSCs and digital video cameras are reviewed, followed by descriptions of the architectures of signal-processing engines. Examples of analog front-end and digital back-end designs are introduced. •In Chapter 10, “Evaluation of Image Quality,” readers learn how each component described in the previous chapters affects image quality. Image quality-related standards are also given. •In Chapter 11, “Some Thoughts on Future Digital Still Cameras,” Eric Fossum, the pioneer of CMOS image sensor technology, discusses future DSC image sensors with a linear extrapolation of current technology and then explores a new paradigm for image sensors. Future digital camera concepts are also addressed. Copyright © 2006 Taylor & Francis Group, LLC DK545X_C000.fm Page 7 Wednesday, July 6, 2005 8:12 AM I would like to extend my gratitude to the contributors to this book, many of whom work actively in the industry, for their efforts and time given to making this book possible. Also, I am grateful to all of my coworkers who reviewed draft copies of the manuscripts: Dan Morrow, Scott Smith, Roger Panicacci, Marty Agan, Gennnady Agranov, John Sasinowski, Graham Kirsch, Haruhisa Ando, Toshinori Otaka, Toshiki Suzuki, Shinichiro Matsuo, and Hidetoshi Fukuda. Sincere thanks also go to Jim Lane, Deena Orton, Erin Willis, Cheryl Holman, Nicole Fredrichs, Nancy Fowler, Valerie Robertson, and John Waddell of the Mar- Com group at Micron Technology, Inc. for their efforts in reviewing manuscripts, appendices, and the table of contents; creating drawings for Chapter 3 and Chapter 5; and preparing the tables and figures for publication. Junichi Nakamura, Ph.D. Japan Imaging Design Center Micron Japan, LTD Copyright © 2006 Taylor & Francis Group, LLC DK545X_C000.fm Page 9 Wednesday, July 6, 2005 8:12 AM Editor Junichi Nakamura received his B.S. and M.S. in electronics engineering from Tokyo Institute of Technology, Tokyo, Japan, in 1979 and 1981, respectively, and his Ph.D. in electronics engineering from the University of Tokyo, Tokyo, Japan, in 2000. He joined Olympus Optical Co., Tokyo, in 1981. After working on optical image processing, he was involved in developments of active pixel sensors.
Load more

Recommended publications
  • Topaz Lens Effects Lens Topaz 3
    User Manual Contents I. Installation 11. About 31 A. How to Install 3 B. Entering Your Key 3 IV. Settings & Parameters C. Host-Specific Installation 3 A. Effects & Presets 32 1. Paint Shop Pro 4 B. Bokeh - Center Focus 33 2. Photo Impact 5 C. Bokeh - SLR 36 Topaz Lens Effects Lens Topaz 3. Irfanview 6 D. Bokeh - Selective 39 D. Uninstalling 7 E. Camera - Pinhole 44 F. Camera - Tilt & Shift 46 II. Introduction G. Camera - Toy 50 A. About Topaz Lens Effects 8 H. Camera - Diffusion 54 1. Primary Functions 8 I. Filter - Dual Tone 55 B. Program Features 9 J. Filter - Fog 59 K. Filter - Graduated Color 6 III. New Features L. Filter - Graduated Neutral Density 61 A. Smart Brush 10 M. Filter - Polarization 62 B. Effects Menu 15 N. Filter - Reflector 63 C. Apply Button 16 O. Filter - Single Tone 64 D. Enhanced Sharpening 17 P. Filter - Streak 65 E. Split Screen View 18 Q. Filter - UV/Haze 65 F. Interface Style 19 R. Filter - Warmth 66 2 S. Lens - Creative Blur 67 IV. Work Area T. Lens - Dual Focus 68 A. Interface 20 U. Lens - Fisheye 70 B. Preview 24 V. Lens - Motion 71 C. Effects & Presets 26 W. Lens - Split Prism 72 1. Applying Presets 26 X. xF - Add Adjustment 73 2. Adding Presets 26 W. xF - Add Geometric Distortion 74 3. Deleting Presets 27 Z. xF - Add Grain 75 4. Importing Presets 28 AA. xF - Add Sharpening 75 5. Exporting Presets 28 AB. xF - Add Vignette 76 6. Sharing Presets 28 AC. xF - Add Vignette - Selective 76 D.
    [Show full text]
  • Digital Still Camera Image File Format Standard
    Digital Still Camera Image File Format Standard (Exchangeable image file format for Digital Still Cameras: Exif) Version 2.1 June 12, 1998 Japan Electronic Industry Development Association (JEIDA) This standard makes no warranty, express or implied, with respect to the use of any intellectual property, such as patents, copyrights and trademarks, belonging to any corporation or individual. Nor does this standard make any warranty regarding system reliability or product liability. Windows™ is a registered trademark of Microsoft Corporation in the United States and elsewhere. FlashPix™ is a registered trademark of Eastman Kodak Company. Revision History This "Digital Still Camera Image File Format Standard" is issued as a standard for the image file format (Exif: Exchangeable image file format) used in digital still cameras and related systems. It was first published in October 1996 as Version 1.0i. Then in May 1997, Version 1.1ii was issued, adding specifications for optional attribute information as well as stipulations relating to format implementation, in addition to the mandatory specifications of Version 1.0. The desire for a uniform file format standard for the image data stored by digital still cameras has increased as these cameras have grown in popularity. At the same time, with the broadening application of this technology, a similar desire has arisen for uniformity of the attribute information that can be recorded in a file. The Version 2.0iii makes improvements to the Exif format for greater ease of use, while allowing for backward compatibility with products of manufacturers currently implementing Exif Version 1.x or considering its future implementation.
    [Show full text]
  • What Resolution Should Your Images Be?
    What Resolution Should Your Images Be? The best way to determine the optimum resolution is to think about the final use of your images. For publication you’ll need the highest resolution, for desktop printing lower, and for web or classroom use, lower still. The following table is a general guide; detailed explanations follow. Use Pixel Size Resolution Preferred Approx. File File Format Size Projected in class About 1024 pixels wide 102 DPI JPEG 300–600 K for a horizontal image; or 768 pixels high for a vertical one Web site About 400–600 pixels 72 DPI JPEG 20–200 K wide for a large image; 100–200 for a thumbnail image Printed in a book Multiply intended print 300 DPI EPS or TIFF 6–10 MB or art magazine size by resolution; e.g. an image to be printed as 6” W x 4” H would be 1800 x 1200 pixels. Printed on a Multiply intended print 200 DPI EPS or TIFF 2-3 MB laserwriter size by resolution; e.g. an image to be printed as 6” W x 4” H would be 1200 x 800 pixels. Digital Camera Photos Digital cameras have a range of preset resolutions which vary from camera to camera. Designation Resolution Max. Image size at Printable size on 300 DPI a color printer 4 Megapixels 2272 x 1704 pixels 7.5” x 5.7” 12” x 9” 3 Megapixels 2048 x 1536 pixels 6.8” x 5” 11” x 8.5” 2 Megapixels 1600 x 1200 pixels 5.3” x 4” 6” x 4” 1 Megapixel 1024 x 768 pixels 3.5” x 2.5” 5” x 3 If you can, you generally want to shoot larger than you need, then sharpen the image and reduce its size in Photoshop.
    [Show full text]
  • Invention of Digital Photograph
    Invention of Digital photograph Digital photography uses cameras containing arrays of electronic photodetectors to capture images focused by a lens, as opposed to an exposure on photographic film. The captured images are digitized and stored as a computer file ready for further digital processing, viewing, electronic publishing, or digital printing. Until the advent of such technology, photographs were made by exposing light sensitive photographic film and paper, which was processed in liquid chemical solutions to develop and stabilize the image. Digital photographs are typically created solely by computer-based photoelectric and mechanical techniques, without wet bath chemical processing. The first consumer digital cameras were marketed in the late 1990s.[1] Professionals gravitated to digital slowly, and were won over when their professional work required using digital files to fulfill the demands of employers and/or clients, for faster turn- around than conventional methods would allow.[2] Starting around 2000, digital cameras were incorporated in cell phones and in the following years, cell phone cameras became widespread, particularly due to their connectivity to social media websites and email. Since 2010, the digital point-and-shoot and DSLR formats have also seen competition from the mirrorless digital camera format, which typically provides better image quality than the point-and-shoot or cell phone formats but comes in a smaller size and shape than the typical DSLR. Many mirrorless cameras accept interchangeable lenses and have advanced features through an electronic viewfinder, which replaces the through-the-lens finder image of the SLR format. While digital photography has only relatively recently become mainstream, the late 20th century saw many small developments leading to its creation.
    [Show full text]
  • Canon EOS 1D
    C J C GETTING THE MOST FROM YOUR EOS-1 CLASS DIGITAL SLR TIPS AND TECHNIQUES: CAMERA HANDLING & MAXIMUM IMAGE QUALITY OVERVIEW Canon’s EOS-1 class digital SLRs (EOS-1D, EOS-1Ds, EOS-1D Mark II and EOS-1Ds Mark II) are clearly the company’s highest quality and most powerful digital SLRs to date. Thanks to their key attributes of EF Lens compatibility, Canon CMOS sensor technology and DIGIC/DIGIC II Image Processors, EOS-1 class digital SLRs produce images with exceptionally low noise, excellent detail and superb color. As with any professional camera system, there are numerous variables in camera operation, lens selection and image quality optimization that must be clearly understood and mastered by the user in order to achieve the best possible results. The purpose of this document is to identify the factors that affect the autofocus (AF) performance and image quality aspects of EOS-1 class digital SLRs, and provide tips and techniques on getting the most out of this powerful camera and lens system. We have intentionally provided detailed explanations to clarify the reasoning behind our recommendations, but at the beginning of the document there is also a brief summary of the main points for your convenience. Thank you for using Canon products! We want you to know that we sincerely appreciate your patronage. OVERVIEW 2 QUICK REFERENCE GUIDE Camera Operation Tips Select focusing points manually: Selecting the focusing point manually speeds up the autofocus system because the camera does not have to decide which focus point or points to use. Manual focusing point selection also allows you to control exactly where the camera is focusing.
    [Show full text]
  • A High Full Well Capacity CMOS Image Sensor for Space Applications
    sensors Article A High Full Well Capacity CMOS Image Sensor for Space Applications Woo-Tae Kim 1 , Cheonwi Park 1, Hyunkeun Lee 1 , Ilseop Lee 2 and Byung-Geun Lee 1,* 1 School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Gwangju 61005, Korea; [email protected] (W.-T.K.); [email protected] (C.P.); [email protected] (H.L.) 2 Korea Aerospace Research Institute, Daejeon 34133, Korea; [email protected] * Correspondence: [email protected]; Tel.: +82-62-715-3231 Received: 24 January 2019; Accepted: 26 March 2019; Published: 28 March 2019 Abstract: This paper presents a high full well capacity (FWC) CMOS image sensor (CIS) for space applications. The proposed pixel design effectively increases the FWC without inducing overflow of photo-generated charge in a limited pixel area. An MOS capacitor is integrated in a pixel and accumulated charges in a photodiode are transferred to the in-pixel capacitor multiple times depending on the maximum incident light intensity. In addition, the modulation transfer function (MTF) and radiation damage effect on the pixel, which are especially important for space applications, are studied and analyzed through fabrication of the CIS. The CIS was fabricated using a 0.11 µm 1-poly 4-metal CIS process to demonstrate the proposed techniques and pixel design. A measured FWC of 103,448 electrons and MTF improvement of 300% are achieved with 6.5 µm pixel pitch. Keywords: CMOS image sensors; wide dynamic range; multiple charge transfer; space applications; radiation damage effects 1. Introduction Imaging devices are essential components in the space environment for a range of applications including earth observation, star trackers on satellites, lander and rover cameras [1].
    [Show full text]
  • Lecture Notes 3 Charge-Coupled Devices (Ccds) – Part II • CCD
    Lecture Notes 3 Charge-Coupled Devices (CCDs) { Part II • CCD array architectures and pixel layout ◦ One-dimensional CCD array ◦ Two-dimensional CCD array • Smear • Readout circuits • Anti-blooming, electronic shuttering, charge reset operation • Window of interest, pixel binning • Pinned photodiode EE 392B: CCDs{Part II 3-1 One-Dimensional (Linear) CCD Operation A. Theuwissen, \Solid State Imaging with Charge-Coupled Devices," Kluwer (1995) EE 392B: CCDs{Part II 3-2 • A line of photodiodes or photogates is used for photodetection • After integration, charge from the entire row is transferred in parallel to the horizontal CCD (HCCD) through transfer gates • New integration period begins while charge packets are transferred through the HCCD (serial transfer) to the output readout circuit (to be discussed later) • The scene can be mechanically scanned at a speed commensurate with the pixel size in the vertical direction to obtain 2D imaging • Applications: scanners, scan-and-print photocopiers, fax machines, barcode readers, silver halide film digitization, DNA sequencing • Advantages: low cost (small chip size) EE 392B: CCDs{Part II 3-3 Two-Dimensional (Area) CCD • Frame transfer CCD (FT-CCD) ◦ Full frame CCD • Interline transfer CCD (IL-CCD) • Frame-interline transfer CCD (FIT-CCD) • Time-delay-and-integration CCD (TDI-CCD) EE 392B: CCDs{Part II 3-4 Frame Transfer CCD Light−sensitive CCD array Frame−store CCD array Amplifier Output Horizontal CCD Integration Vertical shift Operation Vertical shift Horizotal shift Time EE 392B: CCDs{Part II 3-5 Pixel Layout { FT-CCD D. N. Nichols, W. Chang, B. C. Burkey, E. G. Stevens, E. A. Trabka, D.
    [Show full text]
  • Getting the Right Gear
    Chapter 1 Getting the Right Gear In This Chapter ▶ Picking the right camera for the job ▶ Complementing your camera with accessories ports and action photography is like most things in Slife — if you want to be the best at it, you need to have the best gear. Luckily for you, lots of options are available when determining the best gear based on your level of experi- ence and expertise. In this chapter, I help you determine what you’re going to need — including what type of camera and any necessary accessories — based on what you plan on photographing and how comfortable you are behind the lens. The Internet contains a wealth of information, but nothing beats asking other photographers what they’re using. You can share in their camera jubilation or avoid the same pitfalls that they fell into by purchasing that “bargain” point-and-shoot camera that didn’t turn out to be such a bargain after all. ChoosingCOPYRIGHTED the Best Camera MATERIAL for the Job at Hand Whether you’ll be taking photographs at your daughter’s soccer game or trying to make a career out of sports photography, having the right camera for the situation will make all the difference. In the past, very few affordable cameras could capture action as well as the pro’s gear. However, today’s market is full of completely viable options, 003_9781118385302-ch01.indd3_9781118385302-ch01.indd 3 88/31/12/31/12 11:51:51 PMPM 4 Sports & Action Photography In A Day For Dummies from professional dSLRs (digital single-lens reflex), to compact point-and-shoots that you can take everywhere you go, to smartphones with surprisingly impressive cameras good for the candid shots on the go.
    [Show full text]
  • 1/2-Inch Megapixel CMOS Digital Image Sensor
    MT9M001: 1/2-Inch Megapixel Digital Image Sensor Features 1/2-Inch Megapixel CMOS Digital Image Sensor MT9M001C12STM (Monochrome) Datasheet, Rev. M For the latest datasheet, please visit www.onsemi.com Features Table 1: Key Performance Parameters Parameter Value • Array Format (5:4): 1,280H x 1,024V (1,310,720 active Optical format 1/2-inch (5:4) pixels). Total (incl. dark pixels): 1,312H x 1,048V Active imager size 6.66 mm (H) x 5.32 mm (V) (1,374,976 pixels) • Frame Rate: 30 fps progressive scan; programmable Active pixels 1,280 H x 1,024 V • Shutter: Electronic Rolling Shutter (ERS) Pixel size 5.2 m x 5.2 m • Window Size: SXGA; programmable to any smaller Shutter type Electronic rolling shutter (ERS) Maximum data rate/ format (VGA, QVGA, CIF, QCIF, etc.) 48 MPS/48 MHz • Programmable Controls: Gain, frame rate, frame size master clock Frame SXGA 30 fps progressive scan; rate (1280 x 1024) programmable Applications ADC resolution 10-bit, on-chip Responsivity 2.1 V/lux-sec • Digital still cameras Dynamic range 68.2 dB • Digital video cameras •PC cameras SNRMAX 45 dB Supply voltage 3.0 V3.6 V, 3.3 V nominal 363 mW at 3.3 V (operating); Power consumption General Description 294 W (standby) Operating temperature 0°C to +70°C The ON Semiconductor MT9M001 is an SXGA-format with a 1/2-inch CMOS active-pixel digital image sen- Packaging 48-pin CLCC sor. The active imaging pixel array of 1,280H x 1,024V. It The sensor can be operated in its default mode or pro- incorporates sophisticated camera functions on-chip grammed by the user for frame size, exposure, gain set- such as windowing, column and row skip mode, and ting, and other parameters.
    [Show full text]
  • More About Digital Cameras Image Characteristics Several Important
    More about Digital Cameras Image Characteristics Several important characteristics of digital images include: Physical Size How big is the image that has been captured, as measured in inches or pixels? File Size How large is the computer file that makes up the image, as measured in kilobytes or megabytes? Pixels All digital images taken with a digital camera are made up of pixels (short for picture elements). A pixel is the smallest part (sometimes called a point or a dot) of a digital image and the total number of pixels make up the image and help determine its size and its resolution, or how much information is included in the image when we view it. Generally speaking, the larger the number of pixels an image contains, the sharper it will appear, especially when it is enlarged, which is what happens when we want to print our photographs larger than will fit into small 3 1\2 X 5 inch or 5 X 7 inch frames. You will notice in the first picture below that the Grand Canyon is in sharp focus and there is a large amount of detail in the image. However, when the image is enlarged to an extreme level, the individual pixels that make up the image are visible--and the image is no longer clear and sharp. Megapixels The term megapixels means one million pixels. When we discuss how sharp a digital image is or how much resolution it has, we usually refer to the number of megapixels that make up the image. One of the biggest selling features of digital cameras is the number of megapixels it is capable of producing when a picture is taken.
    [Show full text]
  • CMOS Active Pixel Image Sensors for Highly Integrated Imaging Systems
    IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 32, NO. 2, FEBRUARY 1997 187 CMOS Active Pixel Image Sensors for Highly Integrated Imaging Systems Sunetra K. Mendis, Member, IEEE, Sabrina E. Kemeny, Member, IEEE, Russell C. Gee, Member, IEEE, Bedabrata Pain, Member, IEEE, Craig O. Staller, Quiesup Kim, Member, IEEE, and Eric R. Fossum, Senior Member, IEEE Abstract—A family of CMOS-based active pixel image sensors Charge-coupled devices (CCD’s) are currently the dominant (APS’s) that are inherently compatible with the integration of on- technology for image sensors. CCD arrays with high fill-factor, chip signal processing circuitry is reported. The image sensors small pixel sizes, and large formats have been achieved and were fabricated using commercially available 2-"m CMOS pro- cesses and both p-well and n-well implementations were explored. some signal processing operations have been demonstrated The arrays feature random access, 5-V operation and transistor- with charge-domain circuits [1]–[3]. However, CCD’s cannot transistor logic (TTL) compatible control signals. Methods of be easily integrated with CMOS circuits due to additional on-chip suppression of fixed pattern noise to less than 0.1% fabrication complexity and increased cost. Also, CCD’s are saturation are demonstrated. The baseline design achieved a pixel high capacitance devices so that on-chip CMOS drive electron- size of 40 "m 40 "m with 26% fill-factor. Array sizes of 28 28 elements and 128 128 elements have been fabricated and ics would dissipate prohibitively high power levels for large characterized. Typical output conversion gain is 3.7 "V/e for the area arrays (2–3 W).
    [Show full text]
  • Nikon D2hs Brochure
    Nikon Digital SLR Camera D2Hs Specifi cations Type of Camera Lens-interchangeable digital SLR camera Exposure Metering TTL full-aperture exposure metering system; Effective Pixels 4.1 million System 1) D-/G-type Nikkor lenses support 3D-Color Matrix Metering II using the Image Sensor JFET image sensor LBCAST, 23.3 x 15.5mm size, 4.26 million total pixels 1,005-pixel RGB Sensor while other AF Nikkor lenses with built-in CPUs Recording Pixels [L] 2,464 x 1,632-pixel / [M] 1,840 x 1,224-pixel support Matrix Metering (Non-CPU lenses require manual input of lens data) Sensitivity ISO equivalency 200 to 1600 (Hi-1 and Hi-2 available) 2) Center-Weighted Metering (75% of the meter’s sensitivity concentrated on the Storage System NEF (12-bit uncompressed or compressed RAW), 8mm dia. circle) given to 6, 10 or 13mm dia. circle in center of frame, or weighting Exif 2.21, DCF 2.0 and DPOF compliant based on average of entire frame (uncompressed TIFF-RGB or compressed JPEG) 3) Spot Metering (3mm dia. circle, approx. 2% of entire frame); metering position Storage Media CompactFlash™ (CF) Card (Type I / II) and Microdrive™ can be linked to the focus area when using Nikkor lenses with built-in CPU Shooting Modes 1) Single frame shooting [S] mode: advances one frame for each shutter release Exposure Metering 1) 3D-Color Matrix Metering II: EV 0 to 20 2) Continuous high shooting [CH ] mode: 8 frames per second (fps) Range 2) Center-Weighted Metering: EV 0 to 20 [up to 50 (JPEG)/40 (TIFF)/40 (RAW:NEF) consecutive shots] 3) Spot Metering: EV 2 to 20 [at normal
    [Show full text]