ELE882 Intro to D Dr. Lei Gao ELE882 Intro to Digital Image Processing What is Digital Image Processing? • Processing of digital images by means of a digital computer • We process to: • Facilitate transmission, printing and storage » Efficiently store an image in a digital camera » Send an image through mobile phone • to restore by improving the quality in an objective way » Remove scratches from an old photo » Remove blur, remove noise » Based on mathematical or probabilistic models • To enhance an image in a subjective way » Increase contrast, colourize » Expand dynamic range ELE882 Intro to Digital Image Processing Restoration of Images ELE882 Intro to Digital Image Processing Colorize ELE882 Intro to Digital Image Processing Noise removal ELE882 Intro to Digital Image Processing Remove Blur ELE882 Intro to Digital Image Processing Enhancement ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing Compression ELE882 Intro to Digital Image Processing • Analyze so that we can extract information Face detection Fingerprint identification Red-eye removal Object tracking ELE882 Intro to Digital Image Processing Mapping and geographical analysis Earthquake analysis From space ELE882 Intro to Digital Image Processing Tumor detection ELE882 Intro to Digital Image Processing What is a Digital Image? • 2-Dimensional function f(x,y) – – – – Can be thought of as a 2-D signal x & y are the spatial co-ordinates the amplitude f at any pair (x,y) is known as the intensity When x, y, and f(x,y) are finite and discrete then the image is DIGITAL f (x, y) ELE882 Intro to Digital Image Processing Origins of Digital Image Processing View from the Window at Le Gras First photograph taken in 1826 by Joseph Nocéphore Niépce using bitumen in a process knows as heliography Since then it is estimated that humanity has taken over 3.5 trillion (3,500,000,000,000) pictures. Not only that, but 10% of those 3.5 trillion were taken in the past year. ELE882 Intro to Digital Image Processing http://100photos.time.com/photos/joseph-niepce-first-photograph-window-le-gras Displayed in an oxygen-free case at the University of Texas ELE882 Intro to Digital Image Processing Almost 42% of all the photos taken in history will have been taken in 2016. ELE882 Intro to Digital Image Processing • First photograph of humans in 1838 – By Louis Daguerre > 10 minute exposure! ELE882 Intro to Digital Image Processing First “Selfie” Robert Cornelius, 1839 ELE882 Intro to Digital Image Processing http://100photos.time.com/photos/philippe-kahn-first-cell-phone-picture First Cell-Phone Picture (1997) Intro to Digital Image Processing ELE882 Ultimate “Selfie” ELE882 Intro to Digital Image Processing First “motion pictures” (1878) http://100photos.time.com/photos/eadweard-muybridge-horse-in-motion ELE882 Intro to Digital Image Processing • 1920 – Bartlane Transmission System – Was more of a “facsimile” system – Utilized a punched tape (like ticker tape) – 5 levels of grey – Picture was coded for cable transmission between London and New York (submarine cable) – Result looked like an embroidered B&W piece of paper ELE882 Intro to Digital Image Processing • 1929 – Bartlane system increased to 15 levels of grey! ELE882 Intro to Digital Image Processing • What we know as “Digital Imaging” would not be possible without the development of the digital computer – 1940 - CPU, memory, conditional branching – 1949 – transistor – 1950s & 1960s – COBOL, Fortran ELE882 Intro to Digital Image Processing • First Digital Photo taken in 1957 – Taken by Russell Kirsch (picture of his son Walden) – 176 x 176 pixels (0.1 Megapixel) ELE882 http://www.theatlantic.com/technology/archive/2014/11/the-history-of-digital-imaging-began-with-a-baby-picture/382161/ Intro to Digital Image Processing – 1958 – Integrated Circuits – 1960s – Operating systems • First computers to do actual Digital Image Processing at Jet Propulsion Lab (JPL) • July 31, 1964: picture of moon from Ranger 7 – taken 17minutes before impact – radioed photographs back as it plunged into the lunar surface, crashing and being destroyed in the process. • JPL worked on improving this image and others ELE882 Intro to Digital Image Processing First image of Earth from Space (December 24, 1968) Earthrise The first image of Earth taken from space was captured by a heavily modified Hasselblad 500 EL camera with custom 70mm Ektachrome film made by Kodak. http://100photos.time.com/photos/nasa-earthrise-apollo-8 ELE882 Intro to Digital Image Processing • 1973 – Lenna image appears – Most widely used and most famous test image for all sorts of image processing algorithms ….scanned from a Playboy centerfold! ELE882 Intro to Digital Image Processing – 1975 -First Digital Camera by Kodak and Steve Sasson: (Took 23 seconds to create an image) – 1978 – microprocessor (CPU, memory, I/O) – 1981 – IBM PC – 2009 – Kodak stops making Kodachrome film – 2012 – Kodak files for Bankruptcy ELE882 Intro to Digital Image Processing Today's smartphones put nearly-professional grade cameras in everyone's pockets. Compared to the first cell phone camera's 0.3 megapixels, new smarthphone cameras exist with upwards of 41 megapixels ELE882 Intro to Digital Image Processing World’s Most Expensive Camera • With only 25 ever created, the 1923 Prototype Leica Oseries sold at auction for US$2.8 million making it the world’s most expensive camera to date ELE882 Intro to Digital Image Processing • Further advancements in VLSI, memory, CPU, display technology, sensors and storage, in the last 30 years, have made digital imaging what it is today: ELE882 Intro to Digital Image Processing Importance • Facebook had 100 billion photo uploads in the first HALF of 2011. – – – – – That’s about 10,000 X larger than the library of congress The number of photo uploads are on the rise exponentially 14.58 million photo uploads per hour, 243,000 photo uploads per minute, 4,000 photo uploads per second. • Google has indexed over 1 Trillion web pages – Most pages have at least one image • Instagram has 55 Million new images a day • Twitter says 36% of tweets are images – Estimates are about 40-50 million unique images are tweeted ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing “Every 2 minutes today we snap as many photos as the whole of humanity took in the 1800s.” ELE882 http://hyperallergic.com/48765/how-many-photos-do-americans-take-a-year/ Intro to Digital Image Processing On average, there are 9,000 photos shared on SnapChat every SECOND It would take about 10 years to view all the photos shared on SnapChat in the last hour ELE882 Intro to Digital Image Processing • Digital Images are an important and essential part of society • Availability, cost reduction, size reduction and integration of acquisition and displays continue to make digital imaging an important field • In turn, the areas of application are increasing as new ways to use digital imaging are being made possible ELE882 Intro to Digital Image Processing We can categorize imaging according to the Electromagnetic (EM) Spectrum ELE882 Intro to Digital Image Processing EM Band Imaging • Gamma-ray imaging – Nuclear medicine, astronomical observations. • X-ray Imaging – Electrons hit nuclei that release x-rays – Medical diagnostics (CAT scans, x-ray scans), industry, astronomy. • Ultra-violet imaging – Fluorescence microscopy, astronomy • Visible & Infrared-band imaging (most widely used) – Light microscopy, astronomy, remote sensing, industry, law enforcement, consumer, etc. • Micro-wave and radio band imagery – Radar, Medicine (MRI), astronomy ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing Non-EM band Imaging • Acoustic imaging (hundreds of Hz) – Geological exploration (oil exploration) • Ultrasound imaging (millions of Hz) – Industry and medicine especially in obstetrics, determine the health of the fetal development • Electron microscopic imaging – Used to achieve magnification of 10,000X or more (Visible light microscopy limited to about 1000X) • Synthetic imaging – 3D modeling or visualization systems for flight simulators, machine design, special effects and animations,etc. ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing ELE882 Intro to Digital Image Processing Images require lots of storage space , e.g., a colour 10Megapixel picture in RAW uncompressed 8 bits/pixel requires 10,2 MB Displaying and/or printing exactly what has been captured in a digital images is not straightforward A device sensitive to the energy we wish to image (i.e., visible light) Most processing is done with software on computers and DSPs and sometimes on specialized fast hardware ELE882 Intro to Digital Image Processing Course Scope • Image Formulation – Human vision and perception – Image acquisition, sampling, storage – Pixel notations/relationships • Elementary Image Operations – Mathematical tools – Image arithmetic • Image Enhancement – Intensity transformations and histogram processing – Spatial domain processing – Frequency domain processing ELE882 Intro to Digital Image Processing • Image Restoration – Noise models – Removal of noise (additive and multiplicative) • Image Reconstruction – Geometrical mappings – Resampling, interpolation • Basic Colour Image Processing – Extension of grey scale – Simple spatial filters ELE882 Intro to Digital Image Processing
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