The document defines digital image processing and describes the key components of a digital image processing system. It discusses the major components which include image sensing, specialized hardware, computers, software modules to perform tasks like preprocessing, enhancement and compression. It also covers mass storage, image displays, hardcopy devices and networking capabilities required for a digital image processing system. Applications of digital image processing discussed include medical imaging, remote sensing, astronomy and more.

1. - Nagashree B N
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2. • An image may be defined as a two-dimensional function, f(x, y)
where x and y are plane coordinates
• The amplitude of f at any pair of coordinates (x, y) is called the
intensity or gray level of the image at that point
• An image is called digital image when value of x, y and f are all
finite and discrete quantities
• Processing digital images by means of a digital computer is called
DIP
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3. • A digital image is composed of a finite number of elements called
pixels, each of which has a particular location and value
• f(x, y)
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Y
X

4. • Computers can operate on images including ultra-sound, electron
microscopy and computer-generated images
• Three types of image processing are:
• Low-level: Pre Processing performed such as to reduce noise,
contrast enhancement, and image sharpening (I/O are images)
• Mid-level: inputs may be images, outputs are attributes from
operations such as Segmentation, Object description &
Classification.
• High-level: Image analysis
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5. • One application of DIP was in the newspaper industry
• Pictures were first sent by submarine cable between London and
New York
• Later Bartlane cable picture transmission system was introduced
which reduced image transmission time
• DIP grew with growth of digital computer
• Applications of DIP can be found in astronomy, biology, nuclear
medicine, law enforcement, defense and industry
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6. Gamma-Ray Imaging:
• Major use of gamma ray images include nuclear medicine and
astronomical observations
• In nuclear medicine, gamma ray detector produces image by
collecting gamma rays emitted by radioactive isotopes which is
injected to a patient
• These images are used to locate sites of bone pathology, such as
infections or tumors
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7. X-Ray Imaging:
• Applications of X-Ray are:
- Used in medical diagnostics
- Used in industry to examine circuit boards for missing
components or broken traces
- Angiography
- Computerized Axial Tomography (CAT)
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8. Ultraviolet band Imaging:
• Applications of UV-Ray are:
• It is used in lithography, industrial inspection, lasers, biological
imaging and astronomical observation
• Ultraviolet light is used in fluorescence microscopy
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9. Visible and Infrared Band Imaging:
• Application area includes light microscopy, astronomy, remote
sensing, industry and law enforcement
Microwave Band Imaging:
• Its application is radar, which has ability to collect data over
virtually any region at any time, regardless of weather or ambient
lighting conditions
Radio Band Imaging:
• It is used in medicine for Magnet Resonance Imaging(MRI)
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11. • The image acquisition stage involves preprocessing, such as scaling.
• Image enhancement is the process of manipulating an image to make it
more suitable for a specific application [subjective]
• Image restoration is an area that also deals with improving the
appearance of an image [objective]
• Color image processing deals with processing color image for various
purpose
• Wavelets are the foundation for representing images in various degrees
of resolution. This representation subdivides the images into smaller
regions
• Compression deals with techniques for reducing the storage required to
save an image, or the bandwidth required to transmit it.
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12. • Morphological processing deals with tools for extracting image
components that are useful in the representation and description of
shape
• Segmentation procedures partition an image into its constituent parts
or objects.
• Representation and description (feature selection) is raw pixel data,
constituting either the boundary of a region (i.e., the set of pixels
separating one image region from another) or all the points in the
region itself.
• Recognition is the process that assigns a label to an object based on its
descriptors
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14. Sensing
• Two elements are required to acquire digital images.
i) A physical device that is sensitive to the energy radiated by the
object we wish to image.
ii) A digitizer, is a device for converting the output of the physical
sensing device into digital form
Specialized image processing hardware (front-end subsystem)
• It usually consists of the digitizer plus hardware that performs other
primitive operations
Computer
• In DIP system, computer is a general-purpose computer and can range
from a PC to a supercomputer
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15. Software
• Software for image processing consists of specialized modules that
perform specific tasks.
Mass storage capability
• It is must in image processing applications to provide adequate storage.
Categories of digital storage are:
(1) short term storage for use during processing,
(2) on-line storage for relatively fast recall,
(3) archival storage, characterized by infrequent access
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16. Image displays
• They are mainly color TV monitors. Monitors are driven by the outputs
of image and graphics display cards that are an integral part of the
computer system.
Hardcopy devices
• They are for recording images include laser printers, film cameras, heat-
sensitive devices, inkjet units, and digital units, such as optical and CD-
ROM disks
Networking
• It is almost a default function in any computer system in use today
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