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Image is an Artifact that reproduce the likeness of some subjects usually a physical object.

Images are pictures! A picture that represents visual information. Used to save visual experiences. A picture is worth a 1000 words…I

think more!!!

How are non-digital images stored? Photographic film Canvas/paint Digitally

Imaging is the process of acquiring images.

Shorthand for image acquisition.

Process of sensing our surroundings and then representing the measurements that are made in the form of an image.

Passive imaging – employs energy sources that are already present in the scene.

Active imaging – involves use of artificial energy sources to probe our surroundings.

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Passive imaging is subject to the limitations of existing energy sources.

Passive Imaging

Active imaging is not restrictive in this way but is invariably a more complicated & expensive procedure.

Active imaging predominates in medical field, where precise control over radiations sources is essential.

Active imaging is also an important tool in remote sensing.

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Active Imaging

DICOM - Digital Imaging and Communications in Medicine

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User Consortia (e.g., HL7)

Organizations (e.g., NEMA, IEEE)

US Government Agencies (e.g., ANSI, NIST)

Foreign Government Agencies (e.g., CEN)

United Nations (e.g., ISO, CCITT)

The name was changed to separate the standard from the originating body

1991 - Release of Parts 1 and 8 of DICOM

1992 - RSNA demonstration, Part 8

1993 - DICOM Parts 1-9 approved, RSNA demonstration of ALL parts

1994 - Part 10: Media Storage and File Format

1995 - Parts 11,12, and 13 plus Supplements

MAGN

ETOM

Information Management System

Storage, Query/Retrieve,

Study Component

Query/Retrieve, Patient & Study Management

Query/Retrieve

Results Management

Print Management

Media Exchange

LiteBox

SOP

Data Dictionary

Real-World Object

Information Object DIMSE Service Group

Composite Verification

Storage

Query/Retrieve

Study Content Notification

Normalized Patient Management

Study Management

Results Management

Basic Print Management

Joint CEN-DICOM development

Medicom = DICOM

MIPS 95 work is underway with JIRA

IS&C Harmonization is also in progress

HL7 Harmonization continuing interest

New DICOM organization Companies: NEMA and non-NEMA

ACR, ACC, CAP, ...

individuals

Networking is a critical component of all

medical imaging systems

Support for Open Communication Standards is a

MUST

DICOM is here, NOW

DICOM products exist on the market

DICOM is emerging as THE common protocol for

medical image communication - WORLD WIDE!

Images stored in digital form!

Many ways of acquiring images

Scanner

Digital Camera

Others…

Many ways of storing images

Gif

Tiff

BMP

JPG

Others…

JPEG (Joint Photographic Experts Group)

GIF (Graphic Interchange Format)

PNG (Portable Network Graphics)

TIFF (Tagged Image File Format)

PGM (Portable Gray Map)

FITS (Flexible Image Transport System)

BMP (Bitmap Format)

JPEG - Joint Photographic Experts Group JPEG is designed with photographs in mind.

It is capable of handling all of the colors needed. JPEGs have a lossy way of compressing images.

At a low compression value, this is largely not noticeable, but at high compression, an image can become blurry and messy.

.jpg

JPEG cautions: • Images with hard edges, high contrasts, angular areas, and

text suffer from JPEG compression. • Scanned “natural” photographs do not lose much,

especially at High or Maximum quality. • Only save finished images as JPEGs, every time you open

and save again, even if you don’t edit, you lose quality. • Always keep the original non-JPEG version (the native .psd

format).

So why use JPEG? • It is the best format for photographic images on the Web. • It’s compression ability is very great.

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GIF - Graphics Interchange Format

GIF is the most popular on the Internet, mainly because of its small file size. It is ideal for small navigational icons and simple diagrams and illustrations where accuracy is required, or graphics with large blocks of a single color. The format is loss-less, meaning it does not get blurry or messy.

The 256 color maximum is sometimes tight, and so it has the option to dither, which means create the needed color by mixing two or more available colors.

GIF use a simple technique called LZW compression to reduce the file sizes of images by finding repeated patterns, but this compression never degrades the image quality.

.GIF

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The GIF format is one of the most commonly used graphic file formats, especially on the Internet.

The GIF format is exceedingly useful in that it can contain animations. Its internal structure is such that it can store multiple images and the controls to make them appear as real time animation animated GIF.

The GIF format also allows a special color as to be specified as "using the background." This results in the image looks like transparent transparent GIF.

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Portable Network Graphic (PNG) which is pronounced as “Ping”.

Alternative to GIF, a lossless compression scheme is used.

Support three image type: true color, grayscale, palette-based (8-bit). JPEG supports the first 2.

GIF supports the 3rd one.

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Advantages Better Compression

○ Deflate is an improved version of the Lempel-Ziv compression algorithm.

Improve Interlacing ○ Display image quicker than Interlaced GIF.

True Color and Transparency ○ Support 16-bit (Grey scale) or 48-bit (True Color)

○ 16-bit for alpha channel (Transparency).

Gamma storage ○ Store the gamma setting of the platform of the creator.

Disadvantages Not support by old browsers (Netscape 2,3,4 and IE 2,3,4)

TIFF - Tagged Image File Format

Widely used cross platform file format also designed for printing.

A bitmap image format.

TIFF supports lossless LZW compression which also makes it a

good archive format for Photoshop documents.

A popular format for grayscale images (8 bits/pixel)

Closely-related formats are: PBM (Portable Bitmap), for binary images (1 bit/pixel)

PPM (Portable Pixelmap), for color images (24 bits/pixel)

- ASCII or binary (raw) storage

FITS - Flexible Image Transport System

Format of a FITS file (http://fits.gsfc.nasa.gov)

Primary Header: metadata describing instrument, observation & file contents

Primary Data Array: array of 0-999 dimensions – usually a 2D image

+ none or more Extensions:

Array, ASCII Table or Binary Table, each with Header

(New FITS-inspired XML format – VOTable)

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BMP - Bitmap Format

uses a pixel map which contains line by line information.

It is a very common format, as it got its start in Windows.

This format can cause an image to be super large.

Image Processing is any form of signal processing for which our input is an image, such as photographs or frames of video and our output can be either an image or a set of characteristics or parameters related to the image.

Image Processing generally refers to processing of two dimensional picture and by two dimensional picture we implies a digital image.

A digital image is an array of real or complex numbers represented by a finite number of bits.

But now in these days optical and analog image processing is also possible.

Is enhancing an image or extracting information or features from an image.

Computerized routines for information extraction (eg, pattern recognition, classification) from remotely sensed images to obtain categories of information about specific features.

Image processing are of two aspects..

improving the visual appearance of images to a human viewer

preparing images for measurement of the features and structures present.

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❶ Acquisition of Image

Medical image data is acquired one slice at a time.

Resulting data set comprises n slices, each containing w x h pixels.

Basic Steps for Image Processing

❷ Data Storage

Array starts with the first row of the first slice and so on until the end of the first slice.

Next, the array continues with the first row of the second slice, then the second row of the second slice, and so on.

A single slice corresponds to a k space plane acquired in real-time

The “K-Space” undergoes an Inverse Fourier Transform.

Following this mathematical step, we finally have an image

❸ Image Formation

❹ Data Visualisation

Medical image data is commonly visualised by two

methods.

Reslicing

Surface rendering

Since the digital image is “invisible” it must be prepared for viewing on one or more output device (laser printer, monitor, etc.,)

It might be possible to analyze the image in the computer and provide cues to the radiologists to help detect important/suspicious structures (e.g.: Computed Aided Diagnosis, CAD)

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Why do we need Image Processing

Image processing can be done using various software's and languages such as:-

Language

VHDL

C/C++

Software

Matlab

Adobe Photoshop

Irfan view

How Image Processing is done?

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Early 1920’s: One of the first applications of digital imaging was in the newspaper industry

The Bartlane cable picture transmission service

Images were transferred by submarine cable between London and New York

Pictures were coded for cable transfer and reconstructed at the receiving end on a telegraph printer

Early digital image

Mid to late 1920’s: Improvements to the Bartlane system resulted in higher quality images

Improved

digital image Early 15 tone digital

image

New reproduction processes based on photographic techniques

Increased number of tones in reproduced images

1960’s: Improvements in computing technology and the onset of the space race led to a surge of work in digital image processing

A picture of the moon taken

by the Ranger 7 probe

minutes before landing

1964: Computers used to improve the quality of images of the moon taken by the Ranger 7 probe

Such techniques were used in other space missions including the Apollo landings

1970’s: Digital image processing begins to be used in medical applications

Typical head slice CAT

image

1979: Sir Godfrey N. Hounsfield & Prof. Allan M. Cormack share the Nobel Prize in medicine for the invention of tomography, the technology behind Computerised Axial Tomography (CAT) scans

1980’s - Today: The use of digital image processing techniques has exploded and they are now used for all kinds of tasks in all kinds of areas

Image enhancement/restoration

Artistic effects

Medical visualisation

Industrial inspection

Law enforcement

Human computer interfaces

Face detection

Feature detection

Non-photorealistic rendering

Medical image processing

Microscope image processing

Morphological image processing

Remote sensing

Automated Sieving Procedures

Finger print recognization

Applications

Primary purpose is to identify pathologic conditions.

Requires recognition of normal anatomy and physiology.

Create image of body part

Disease Monitoring

Medical imaging is the technique and process used to create images of the human body or it’s parts for clinical purposes .

Non-invasive visualization of internal organs, tissue, etc.

Medical imaging has come a long way since 1895

when Röntgen first described a ‘new kind of ray’.

That X-rays could be used to display anatomical

features on a photographic plate was of immediate

interest to the medical community at the time.

Today a scan can refer to any one of a number of

medical-imaging techniques used for diagnosis and

treatment.

Medical Imaging using Ionising Radiations

The transmission and detection of X-rays still lies at the heart of

radiography, angiography, fluoroscopy and conventional

mammography examinations.

However, traditional film-based scanners are gradually being

replaced by digital systems

The end result is the data can be viewed, moved and stored without

a single piece of film ever being exposed.

Digital Systems

Projection X-ray (Radiography)

Ultrasound

X-ray Computed Tomography (CT)

Magnetic Resonance Imaging(MRI)

Imaging Modalities

Imaging for medical purposes involves the services of radiologists, radiographers, medical physicists and biomedical engineers working together as a team for maximum output. This ensures the production of high quality of radiological service with consequent improvement of health care service delivery.

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Technological advances have made human imaging possible at scales from a single molecule to the whole body.

By linking the anatomical data collected with emerging imaging technologies to computer simulations, researchers now can form truly functional images of individual patients.

These images will allow physicians not only to see what a patient’s organs look like but also how they are functioning even at the smallest dimensions.

A major challenge is how to store, analyze, distribute, understand and use the enormous amount of data associated with thousands of images.

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Biomedical engineering stands at the forefront of this effort because its researchers are able to integrate the engineering tools needed to solve the technological problems of image analysis with the deeper knowledge of the underlying biological mechanisms.

Already, members of the Department of Biomedical Engineering, in close collaboration with the Departments of Applied Mathematics and Statistics, Computer Science, Electrical and Computer Engineering, and Radiology, have pioneered the use of imaging technology in computational anatomy, neuropsychiatry, computer-integrated surgery and cardiac procedures.

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Now, researchers are expanding their imaging efforts into other modalities and organ systems.

Ultimately, their work will contribute to advancing image-guided therapy and to the early diagnosis and treatment of a host of disorders, including heart disease and brain dysfunction.

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Research - Biomedical Imaging

New developments in biomedical imaging provide a window

into complex biological phenomena.

Imaging enables researchers to track the movements of molecules, cells, fluids, gases, or sometimes even whole organisms.

Imaging techniques such as x-ray crystallography and magnetic resonance imaging can also yield information about important biological structures from single proteins to the human brain.

The frontiers of biomedical imaging promise to make diagnosis of disease more accurate and less invasive, and to improve our understanding of disease.

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Imaging research encompasses Imaging of protein complexes involved in synaptic communication in the

brain

Fluorescence tagging of molecules involved in intracellular signalling networks

Non-invasive imaging of cancer

Imaging of human movement using dynamic MR, motion capture systems, and ultrasonic imaging

Molecular and biochemical imaging with PET, SPECT, and optical imaging

Three-dimensional medical imaging of blood flow, blood vessels, and cardiovascular lesions

Functional human brain mapping

Strategies for fusing images across modalities (e.g., CT and MR)

Ultrasonic diagnostic technology in medicine

Computational analysis and reconstruction of complex imaging data

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