PPT-1 of digital image processing and signals
- 2. CONTENT ➢ What is a digital Image? ➢ What is digital image processing? ➢ The history of DIP ➢ Examples of fields that use DIP ➢ Key stages in DIP ➢ MODULE 1: Digital Image Fundamentals ➢ MODULE 2: Spatial Domain and Frequency Domain ➢ MODULE 3: Restoration ➢ MODULE 1: Color image processing, pseudo color, wavelets, morphological image processing ➢ MODULE 5: Segmentation, representation and description
- 3. Image: Image is the projection of 3D scene on 2D plane What is a digital Image? IMAGE ACQUISITION USING SENSOR ARRAYS:
- 4. ➢ Digital image is a two dimensional function f(x,y) ➢ where (x,y) are the spatial (plane) coordinates, and the amplitude of f at any particular coordinates (x,y) is called the intensity of gray level of the image at that point.
- 5. Digital image is composed of a finite number of elements, each of which has a particular location and value. These elements are called Picture elements, image elements, Pels and Pixels
- 6. What is Digital Image Processing? Manipulation of digital images by means of a digital computer for representation in suitable form is known as digital signal processing. Digital image Processing focuses on two major tasks: 1. Improvement of pictorial information for human perception (Enhance the quality of image) 2. Processing of Image data for efficient storage and transmission (to make it efficient for transmitting over low bandwidth communication channel)
- 7. Typical Operations Include: 1. Contrast Enhancement 2. Remove blur from an image 3. Smooth out graininess, Speckle or noise 4. Magnify, minify or rotate an image(image wraping) 5. Geometric Correction 6. Image compression for efficient storage and transmission
- 8. The Image processing can be broken up to Low- Mid – High Level Processes: Pre-processing operations
- 9. HISTORY OF DIGITAL IMAGE POCESSING: In 1920s, submarine cables were used to transmit digitized newspaper pictures between London and New York named as “Bartlane Systems” (less than three hours). Transmitter (Digitized newspaper pictures) Submarine Cables Receiver (Reproduction of pictures by telegraphic printers) London New York Bartlane cable picture transmission system FIGURE 1.1 A digital picture produced in 1921 from a coded tape by a telegraph printer with special typefaces.
- 10. Reproduction of pictures by telegraphic printers Reproduction of pictures by photographic printers In 1921, printing procedure was changed to photographic reproductions from tapes perforated at telegraph receiving terminals. This improved both in tonal quality and in resolution. It had five discrete intensity levels – 5 tone quality
- 11. After 1929, Bartlane systems was capable of coding 15 level Figure. Unretouched cable picture of Generals Pershing (right) and Foch, transmitted in 1929 from London to New York by 15-tone equipment.
- 12. Though this bartlane system used digital images, these images were not processed because the computers were not involved as they were not invented by that time. So the history of digital image processing is intimately tied to development of digital computer. So now let us see how these digital computer were developed over the decades.
- 13. History of DIP is intimately tied to the development of Digital Computer: In 1940, Introduction of John von Neumann’s of two key concepts. In 1948, Introduction of Transistor at Bell Lab In 1950- 1960, Development of High-level programming languages like COBOL and FORTRAN. In 1958, Introduction of ICs at Texas Instruments. Early1960, Development of OS Early1970, Development of the Microprocessor 1981, Introduction of personal computer by IBM Late 1970s- Today: Progressive miniaturization of components LSI - VLSI - ULSI.
- 14. 1960: Improvements of computing technology and the onset of the space race led to a surge of work in digital image processing In 1964, computer processing techniques were used, when pictures of the moon transmitted by Ranger 7 (a U.S. spacecraft) were processed by a computer to correct various types of image distortion inherent in the on-board television camera. This was the basis of modern image processing techniques. A picture of the moon taken by the Ranger 7 probe 17 minutes before landing (Jet propulsion Lab by Calfornia)
- 15. In the late 1960s and early 1970s, to be used in medical imaging, remote sensing, industries, Earth resources observations, and astronomy. In 1970s, Digital image processing begins to be used in medical imaging Typical Head slice CAT image 1979: Sir Godfrey and Porf. Allan share the Nobel prize in medicine for the invention of tomography, the technology behind Computerized Axial Tomography (CAT) scans).
- 16. 1980s – Today: The use of digital image processing has exploded and they are now used for all kinds of tasks in all kinds of areas. Image enhancement/ restoration Artistic effects Medical Visualization Industrial Inspection Law Enforcement Human computer interfaces
- 17. Examples of Fields That Use DIP The extent of image processing applications can be better understood by categorizing images based on their sources. The principal energy source for images is the electromagnetic energy spectrum EM waves = stream of massless particles, each travelling in a wavelike pattern at the speed of light. Spectral bands are grouped by energy/photon Gamma rays, X-rays, UV, Visible, Infrared, Microwaves, radio waves.
- 19. Gamma Rays Imaging: Used in Nuclear Medicine and astronomical observations Nuclear medicine: The approach is to inject a patient with a radioactive isotope that emits gamma rays as it decays. Images are produced from the emissions collected by gamma-ray detectors. Positron emission tomography (PET): The patient is given a radioactive isotope that emits positrons as it decays. When a pos itron meets an electron, both are annihilated and two gamma rays are given off. These are detected and a tomographic image is created using the basic principles of tomography. (a) Bone Scan (b) white spot indicates: Tumor in brain and lungs
- 20. X-Rays Imaging: Oldest source of EM radiation for imaging Identify fracture present in the bone Angiography (identify the irregularities/blockages present in the blood vessels) Used for CAT scans Astronomy Used for Industrial inspection (X-ray image of an electronic circuit board missing component or broken traces)
- 21. Ultraviolet Imaging: Used for lithography industrial inspection fluorescence microscopy, lasers, biological imaging, and astronomy Mostly used fluorescence microscopy. Photon of UV light collides with electron of fluorescent material to elevate its energy. Then its energy falls and it emits red light. Fluorescence microscopy image of a normal corn Smut con: A disease of cereals, corn, onions
- 22. Visible and Infrared Imaging: Used for light microscopy, astronomy, remote sensing, industry and law enforcement. Examples of light microscopy images. (a) Taxol (anti cancer agent), magnified (b) Cholesterol (c) electronic circuit board (d) Nickel oxide thin film (e) Surface of audio CD (f) Organic super conductor
- 23. Visible and Infrared Imaging: Remote Sensing. Satellite image of Washington DC, Building, Road, Vegetation and River flowing in the city.
- 24. Visible and Infrared Imaging: Industrial Applications Inspect for missing parts, missing pills, unacceptable bottle fill, unacceptable air pockets, anomalies in cereal color incorrectly manufactured replacement lens for eys
- 25. Microwave Imaging: Radar is dominant application Spaceborne radar image of mountainous region in southeast Tibet.
- 26. Radio Band Imaging: Widely used in medicine and astronomy Magnetic resonance imaging (MRI): ➢ Places patient in powerful magnet ➢ Passes radio waves through body in short pulses ➢ Each pulse causes a responding pulse of radio waves to be emitted by patients tissues. ➢ Location and strength of signal is recorded to from image MRI can produce images in any plane. MRI images of a human knee and spinal cord.
- 27. Key Stages in Digital Image Processing:
- 28. Fundamentals steps in Digital Image Processing:
- 29. Image Acquisition: First stage is image acquisition. It has some pre processing operation like scaling of image rotting an image etc..
- 30. Image Enhancement: Manipulating the image. Various enhancement techniques are available (a) Original Image (b) Enhanced Image
- 31. (a) Full body PET scan. (b) Image enhanced using homomorphic filtering.
- 32. Image Restoration: Improving the quality of image by removing noises. Objective approach. It uses mathematical and probabilistic model for representing the images (a) Original Image (b) Restore Image
- 33. Morphological processing is a tool used to extract the components for representation and description of shapes of the object. Different algorithms are available.
- 34. Image segmentation is a process of partitioning of an image into its constituent parts and objects. Region-based segmentation and object-based segmentation.
- 35. Object Recognition is assigning a label to the object which is being recognized or which has been identified. Mostly used to law enforcement to recognize the vehicle or vehicle number.
- 36. Representation: two types, boundary and region representation Boundary: if the raw pixel data constitutes the boundary of object we say it is a boundary representation. Focus is towards the shape of object. Region: if raw pixel data is inside the region of object. Focus on internal properties of object like texture of obect etc.. Description: extracting the attributes from the images in order to identify the features.
- 37. Image Compression: As we know, high quality images require high memory to store the data. So image compression is used to minimize the data storage for a particular image. Different image compression are available like jpeg, png, tiff, gis etc. Also used to reduce the bandwidth while transmitting the images.
- 38. Color image processing: used to identify the object present in the image
- 39. Components of an Image Processing System
- 40. Image Sensor: First thing we need is an image, so for the basic component required is an image sensor. Based on the problem we are going to capture an image.
- 41. Image Sensor has two elements: 1. Physical Device is very sensitive to the energy radiated by the object which we wish to capture or wish which we wish to image 2. Digitizer is a device which converts the output of this physical device into digital form A good example for this is a digital video camera, the sensor produce electrical output corresponding to the light intensity received, and these electrical outputs are converted to digital form by this digitizer Physical Device Digitizer Device
- 42. So in order to perform image processing operation like digitization and all that we require some hardware components so the next basic component require is the hardware. So some specialized image processing hardware are used here. Specialized Hardware components: In this component 1. digitizer 2. ALU: which perform some primitive operations, arithmetic and logical operations are performed on the entire end image, here the ALU performs averaging operation on the digitized image. This component is also called as front end subsystem. Ex: Digital Video Camera: Digitizing and averaging of the video images at 30 frames per second is made by the ALU present in this hardware component. Physical Device Digitizer Device Specialized Hardware Components
- 43. So in order to process an image, we require image, sensor and hardware devices. In order to control this we require a computer. Computer: 1. General purpose computers: Computer can be any well equipped PC machine that is used that is suitable for performing off-line image processing operations 2. Dedicated computers: For some dedicated applications, Custom computers are used in order to achieve higher level of performance. Physical Device Digitizer Device Specialized Hardware Components Computers
- 44. Next in order to process an image. The image processing system should contain software as well. Computers are not sufficient without software so software or required in order to process an image. Software: Software used in image processing applications are contains special specialized modules which perform specific tasks A well designed package allow those users to write the program to minimum and utilize the specialized modules to the maximum as well. Some more sophisticated packages allows uses to integrate these specialized modules, so software is also an important component in order to process an image. Physical Device Digitizer Device Specialized Hardware Components Computers Software
- 45. when once the image is processed and the results are obtained so now we require storage. So the next basic component is the mass storage. Mass Storage: The mass storage is an important consideration in image processing operations For an image of 1024 x 1024 size, having 8 bit intensity level = 1MB memory Physical Device Digitizer Device Specialized Hardware Components Computers Software Mass Storage
- 46. Mass Storage three types: 1. Short term storage: short-term storage is used to store the data temporarily which is used during processing and is needed and a good example for short-term storage. Ex: Frame Buffers. 2. Online storage: online storage is used for relatively fast recall of the data. Ex: Magnetic disk and optic media storage. 3. Archival storage: Archival storage is used where in frequent access is needed. Ex: Magnetic tapes and optic disk.
- 47. Displays: Color monitors, preferably flat TV screen monitors and these displays are driven by the images and graphic display cards which are the integral part of this computer. So the process images can be displayed by using this place display. Physical Device Digitizer Device Specialized Hardware Components Computers Software Mass Storage Displays
- 48. Hard Copy Devices: These soft copy images should be recorded and it should be represented in the hard copy form so for that we require hard copy devices usually laser printers, film cameras, low sensitive devices, inkjet units digital units such as optic disk and CD rom disk. Physical Device Digitizer Device Specialized Hardware Components Computers Software Mass Storage Displays Hard copy devices
- 49. once the images are processed, stored, recorded and produced in the form of hardcopy, after all that we need to transmit the images so for that we required networking Networking is almost a default function in almost all computers in used today. so the key consideration in transmission of images is its bandwidth so at dedicated network would be a best choice for transmission of these images efficiently. So these are all the basic components comprise comprising general purpose system used in digital image process.