Unit-4 Multimedia Introduction:

Multimedia is the field concerned with the computer controlled integration of text, graphics, drawings, still and moving images (Video), animation, audio, and any other media where every type of information can be represented, stored, transmitted and processed digitally.

The Basic Elements of Multimedia: Text Graphic Animation Video Audio

TEXT

characters that are used to create words, sentences, and paragraphs.

The input and output devices are:

Monitor Keyboard Mouse Speaker Titles

Multimediaisarichmediumthataccommodatesnumerousinstructionalstrategies. Multimediaaddressesmanyofthechallengesofinstructioninboththeacademicandcorporateenvironments.Itisaccessibleoverdistanceandtimeandprovidesavehicleforconsistentdelivery.Multimediacanprovidethebestmediumwithwhichtocommunicateaconcept.

Graphics

A digital representation of non-text information, such as a drawing, chart, or photograph.

Animation

Flipping through a series of still images. It is a series of graphics that create an illusion of motion.

Video

photographic images that are played back at speeds of 15 to 30 frames a second and the provide the appearance of full motion.

Multimedia finds its application in various areas including, but not limited to: Advertisements Art Education Entertainment Engineering Medicine Mathematics Business Scientific research

Unicode standards:

The Unicode Standard provides a unique number for every character, no matter what platform, device, application or language. It has been adopted by all modern software providers and now allows data to be transported through many different platforms, devices and applications without corruption. Support of Unicode forms the foundation for the representation of languages and symbols in all major operating systems, search engines, browsers, laptops, and smart phones—plus the Internet and World Wide Web (URLs, HTML, XML, CSS, JSON, etc.). Supporting Unicode is the best way to implement ISO/IEC 10646.

The emergence of the Unicode Standard and the availability of tools supporting it are among the most significant recent global software technology trends.

The International Standard Text Code (ISTC) is a unique identifier for text-based works. The ISO (International Organization for Standardization)standard was developed by TC 46/SC 9 and published in March 2009 as ISO 21047:2009. The authority responsible for implementing the standard is The International ISTC Agency.

Font :

A font is a set of printable or displayable text character s in a specific style and size. The type design for a set of fonts is the typeface and variations of this design form the typeface family . Thus, Helvetica is a typeface family, Helvetica italic is a typeface, and Helvetica italic 10-point is a font. In practice, font and typeface are often used without much precision, sometimes interchangably.

o A glyph is a graphic representation of a character’s shape. A character may be represented by many different glyphs.

o A typeface is a family of graphic characters, often with many type sizes and styles.

The study of fonts and typefaces includes the following:

Font styles

Font sizes

Cases

Serif versus sans serif

o A font is a collection of characters or glyphs of a single size and style belonging to a particular typeface family.

An outline font is a software typeface that can generate a scalable range of font sizes. A bitmap font is a digital represention of a font that is already fixed in size or a limited set of

sizes. The two most popular outline font software programs on today's computers are

1. TrueType 2. Adobe's Type 1.

TrueType fonts come with both Windows and Macintosh operating systems. However, Type 1 is a standard outline font (ISO 9541). Both TrueType and Type 1 fonts can be

used by Adobe's PostScript printers (although Adobe says that Type 1 fonts makes fuller use of the PostScript language).

Work with Text :

Copy and paste text to prevent loss

While you add text to your course, you can protect against loss of work if an internet connection loss or software error occurs. You can type in an offline simple text editor, such as Notepad or TextEdit, and then copy and paste your work into your course.

Or, before you submit or save, you can copy all of the text you want to add. Select the text and right-click to copy it. You can also use key combinations to copy and paste:

Windows: Ctrl + A to select all the text, Ctrl + C to copy, and Ctrl + V to paste. Mac: Command + A to select all the text, Command + C to copy, and Command + V to paste.

You will have the best results if you type your text directly in the editor and format it with the available options.

You may see issues when you copy and paste text from a Word document directly into the editor. Your original formatting may not appear as you want. You also may not be able to remove or add formatting after you paste the text into the editor. To avoid the formatting issues, you can remove the formatting and reformat it with the options in the editor.

To remove the Word formatting after you paste the text in the editor, select all the text and select the Remove Formatting icon. Only use this option if you understand that all formatting will be removed. All

bullets, numbered lists, indentations, line spacing, centered text, and font formatting and sizing will be removed.

Or, before you add your text in the editor, you can paste it into an offline simple text editor, such as Notepad or TextEdit, and clear the formatting. Then, you can paste the text into the editor and format it as you want.

Text Compression :

These techniques are particularly intended for compressing natural languagetext and other data with a similar sequential structure such as programsource code. However, these techniques can achieve some compression onalmost any kind of (uncompressed) data.These are the techniques used by general purpose compressors such aszip,gzip,bzip2,7zip, etc..

Compression Models:

Entropy encoding techniques such as Huffman coding and arithmetic coding(only) need a probability distribution as an input. The method fordetermining the probabilities is called a model. Finding the best possiblemodel is the real art of data compression.

There are three types of models:•static•semiadaptive or semistatic•adaptive.

A static model is a fixed model that is known by both the compressor and the decompressor and does not depend on the data that is being compressed. For example, the frequencies of symbols in English language computed from a large corpus of English texts could be used as the model.

A semiadaptive or semistatic model is a fixed model that is constructed from the data to be compressed. For example, the symbol frequencies computed from the text to be compressed can be used as the model. The model has to be included as a part of the compressed data.

•A semiadaptive model adapts to the data to be compressed. Forexample, a static model for English language would be inoptimal tocompressing other languages or something completely different such asDNA sequencies. A semiadaptive model can always be the optimal one.

•The drawback of a semiadaptive model is the need to include themodel as a part of the compressed data. For a short data, this couldcompletely negate any compression achieved. On the other hand, for avery long data, the space needed for the model would be negligable.Sometimes it may possible to adapt the complexity of the model to thesize of the data in order to minimize the total size. (According to theMinimum Descrition Length (MDL) principle, such a model is the bestmodel in the machine learning sense too.)

•Every semiadaptive model can be seen as a static model with adaptableparameters. An extreme case would be to have two static models and aone bit parameter to choose between them.

An adaptive model changes during the compression. At a given point in compression, the model is a function of the previously compressed part of the data. Since that part of the data is available to the decompressor at the corresponding point in decompression, there is no need to store the model.

For example, we could start compressing using a uniform distibution ofsymbols but then adjust that distribution towards the symbol frequencies inthe already processed part of the text.

•Not having to store a model saves space, but this saving can be lost toa poor compression rate in the beginning of the compression. There isno clear advantage either way. As the compression progresses, theadaptive model improves and approaches optimal. In this way, themodel automatically adapts to the size of the data.

•The data is not always uniform. An optimal model for one part may bea poor model for another part. An adaptive model can adapt to suchlocal differences by forgetting the far past.

•The disadvantage of adaptive computation is the time needed tomaintain the model. Decompression, in particular, can be slowcompared with semiadaptive compression.

FILE FORMAT:

The specific format in which an file is saved. The format is identified by the three letter extension at the end of the file name. Every format has its own characteristics, advantages and disadvantages. By defining the file format it may be possible to determine the number of bits per pixel and additional information.

Graphics File Formats

The term "Graphics file" is used to refer to a computer file containing any sort of graphical, non-textual information: diagrams, charts, scanned-in images, files created by painting programs, and so on..

There are two main kinds of graphics file, raster (or bitmapped) and vector. Raster formats, which are more common, store information about individual pixels—the tiny picture elements that provide atoms of colour, like dabs of paint in a Pointillist painting. Vector formats, on the other hand, store information about the lines and curves that make up a drawing. Both make use of compression algorithms, which are methods of storing electronic information (of any sort) in a smaller space.

BMP(Bit-Map)Can be recognized by the ".bmp" extension. It was developed by Microsoft Corporation, and provides a simple, efficient means of storing a wide variety of graphical data. BMP is the standard MS-Windows raster format (BMP files can be created with Windows' Paintbrush and used as "wallpaper" for the background when running Windows.)

GIF(Graphics Interchange Format)Can be recognized by the ".gif" extension and is the most common format for graphical information on the Internet. The format was developed by CompuServe Incorporated in 1987 (the GIF87a format), and

an improvement was made in 1989 (the GIF89a format). GIF files can only contain 256 colours, but the format is popular nonetheless for lower resolution image data: 256 colours is sufficient for many applications.

JPEG(Joint Photographic Experts Group)This format can be recognized by the ".jpg" or ".jpeg" extension and is also quite popular on the Internet.

JPEG uses a ”lossy” compression algorithm. Lossy compression means that some image data is thrown away in order to compress a file into a smaller file size—what you get out when you decompress is not exactly what you put in when you compressed it. While the loss of data may sound undesirable, there are several reasons why it can be used to advantage:

TIFF(Tagged-Image file Format)Can be recognized by the ".tif" or ".tiff" extension, was designed to be powerful and flexible. It stores a very large amount of information about an image, and works well as an intermediary file format between scanners or paint programs and desktop publishing programs. One would scan or paint an image, save it as a TIFF file, import it into a desktop publishing program, and save it as another format. This actually works very well. The use of TIFF has been limited, however, since it is very complex.

EPSs(Encapsulated PostScript)

Uses a ".eps" extension and was also created by Adobe Systems. The Encapsulated PostScript file (EPS) format is supported by most illustration and page layout programs, and in most cases is the preferred format for these applications. Note that this is also the only file format that supports transparent whites in Bitmap mode. EPS is a very complex interpreted language.

PDF(Portable Document File)

Denoted by a ".pdf" extension is yet another Adobe Systems product. The PDF, or Acrobat, format is currently used on the Web to deliver documents, though its use is much less than HTML. Its main advantage is that it requires no additional markup, as with HTML documents, before it can be made available online.

WPG(WordPerfect Graphic File)WPG file format is used by WordPerfect. It first appeared with the release of WordPerfect 5.0, and with the release of version 5.1, the format was changed accordingly. It is advised to use the same format version as the version of WordPerfect in which the image will be used. These files can contain bitmaps, line art, and vector graphics.

WMF(Microsoft Windows Metafile)

These files may contain vector information such as lines circles... Only the bitmap data is extracted. May be 1, 4, 8 and 24 bit. The 4 and 8 bit images may be compressed using the Microsoft RLE compression as in BMP files.

PCXThis format, with a ".pcx" extension, is the oldest, most widely recognized graphic file format used for MS-DOS. It was developed in the early 1980s by ZSoft Corporation; the format has become outdated since the company dissolved.

PNG(Portable Network Graphics)

This format, pronounced “ping” and recognized by the ".png" extension. It is intended to supersede GIF, circumventing the legal difficulties involved with the compression algorithm used in that format, as well as adding useful features such as truecolor and error detection, and a faster version of interlacing.

TGA(Truevision File Format)

The TGA format was developed by Truevision for their Targa and Vista products and is rarely seen nowadayss. Can be recognized by the ".tga" extension and is rarely seen nowadays, but it is still encountered in discussions on file formats.

PIC(Pictor)PIC format files are generated and used by PICTOR, PC-Paint and GRASP and is the standard image file format for the Apple Macintosh.

IFF(Amiga Interchange File Format)The Amiga Interchange File Format (IFF) is used to transfer documents to and from Commodore Amiga computers. The IFF file standard is extremely flexible, and allows all a few formats, not only images, including text to be stored inside an IFF file. IFF files can be exported from an Amiga to a PC.

ICO

Microsoft icon format. Contains a standard device independent bitmap. with a new header on top. Supports I and 4 bits uncompressed.

PSDAdobe Photoshop format for storing 1, 8, 24 and 32 bit images. Can be compressed or uncompressed. Images may also be stored as CMYK data or RGB.

RawThe Raw format is a flexible file format for transferring documents between different applications and computer platforms. Raw format consists of a stream of bytes describing the color information in the file. Each pixel is described in binary format, where 0 equals black and 255 equals white.

o GIF and JPEG on the Web

The two most common graphics file formats on the World Wide Web are GIF and JPEG, and it is worth comparing the two directly.

GIF has the advantages of being “lossless”, having the option of transparency, and being good at compressing large areas of a single colour. JPEG has the advantages of greater compression in general,

many more available colours (16 million, compared with GIF's 256), and being good at compressing images with many subtle distinctions, such as photographs.

Although JPEG is a lossy compression, it stores much more information than GIF to begin with, so real- world images still turn out much better when stored as JPEG images. GIF, on the other hand, is much better at storing anything with sharp lines, including text or any black-and-white image. GIF is also particularly good at grayscale images, since it can display an image of up to 256 grays without loss, which JPEG cannot.

Sound File FormatsThere are three parameters that are common to every sound file and affect the size of that file.

Sampling Rate: Most digital sound files save information as a long series of sound samples, in the same way a film saves moving pictures as a series of still images.

Bits per Sample: Commonly, either 8 or 16 bits are used to represent each sample. Using 16 bits provides for much better quality, but produces files twice as large as 8-bit files.

Number of Channels: Because they work with two separate audio channels, stereo files are usually about twice the size of mono files. It is theoretically possible to record any number of channels, with a concomitant increase in file size. For example, a file intended to be played on a surround-sound system may record seven or more channels, and will thus be about seven times the size of a mono version of the same sound.

MIDIThe Musical Instrument Digital Interface system (MIDI) is designed to interconnect home computers, synthesizers, and so on with a standard interface. A MIDI file describes how each instrument in a synthesized band or orchestra plays—where "instrument" is defined fairly loosely and may refer to anything that makes a sound. MIDI files are often named with a ".mid" or ".midi" extension, and (because they store information in such a different manner from other sound files) are rarely found near other sound files.

Windows PCM waveform (.WAV)

All WAV formatted files follow the RIFF (Resource Information File Format) specification. Most of the special information is saved with the wave file in these formats. The standard Windows PCM waveform contains PCM coded data, which is pure uncompressed pulse code modulation formatted data.

Microsoft ADPCM waveform (.WAV)

Microsoft ADPCM compressed waveform forma consists of 4-bit per channel compressed data. Each 4-bit sample is expanded to 16-bits when loaded. For this reason, it is best to save 16-bit files in this format rather than 8-bit files as the quality will be much greater. In the end, the 16-bit data can still be quickly converted to 8-bit during playback on cards that don't support 16-bit.

IMA/DVI ADPCM waveform (.WAV)

This standard compresses 16-bit waves to 4-bit using a different (faster) method than Microsoft ADPCM, and has different distortion characteristics, which may be better, or worse, depending on the original sample being compressed. Again, it is better to save 16-bit audio in this format than 8-bit. This format allows for 3-bit compression as well at a slightly lower quality. Very few sound drivers support the 3-bit ADPCM, and we have found none that actually work properly.

CCITT mu-Law and A-Law waveforms (.WAV)

These formats compress original 16-bit audio down to 8 bits. The quality is somewhere between 8-bit and 16-bit. Thus, a-law and mu-law encoded waveforms have a higher s/n ration than 8-bit PCM, but at the price of a little more distortion that the original 16-bit audio. The quality is definitely higher than you would get with 4-bit ADPCM formats.

Soundblastervoice file format

The extension ".voc" is most commonly used by the Soundblaster sound card. This format only supports 8-bit audio, mono to 44.1 KHz, and stereo to 22 KHz.

MPEG Layer I & II & III (.MP2, .MP3)

The Motion Picture Experts Group audio file format gives the highest compression with the least amount of quality loss, but is also the slowest. In most cases, it takes longer to load or save an MPEG file than it does to play it. Layer 3 MPEG gives even higher quality. Only the sample rates of 48000, 44100, and 32000 are supported.

MOD

(Amiga SoundTracker) can be recognized by the ".mod" or ".nst" extensions and started out strictly for the Amiga, but is now used widely.

RealAudio 3.0 (.RA)

Use this format to create files for Progressive Networks's streaming audio servers and players.

Sun mLaw

With an ".au" extension, is most commonly used on NeXT and Sun computers. This is the most widely recognized sound format on the Internet, challenged only by the Windows-specific RIFF WAVE format. The most common use for the AU file format is for compressing 16-bit data to 8-bit mu-law data

AIFC (AIF with Compression) ".aif" or ".aiff" is most commonly used on Apple and SGI computers. It shares these extensions with uncompressed AIFF (Audio IFF) files, but this is transparent to the user.

NeXT snd with the extension ".snd" is most commonly used on NeXT and Sun machines—watch out for this extension because it shares it with many others, like the one below.

Tandy snd is yet another ".snd" format made for the Tandy computer, but it is associated with a particular program and so does not tend to be widely distributed.

Video File Format AVI(Audio Video Interleaved)

Windows multimedia video format from Microsoft.

It interleaves standard waveform audio and digital video frames (bitmaps) to provide reduced animation at 15 fps at 160x120x8 resolution. Audio is 11,025Hz, 8-bit samples. It can have either one of the three video compression methods: Microsoft

MPEGAn image- compression scheme for full motion video proposed by the Motion Picture Experts Group, an ISO-sanctioned group. MPEG image scheme offers more compression than the JPEG scheme, which is largely for still images, because it takes advantage of the fact that full motion video is made up of many successive frames consisting of large areas that are not changed - like blue sky background. While JPEG, compresses each still frame in a video sequence as much as possible MPEG also performs "differencing," noting differences between consecutive frames. If two consecutive frames are identical, the second can be stored with the appropriate information. MPEG condenses moving images about three times more tightly than JPEG.

Images:An image is a spatial representation of an object, a two-dimensional or three-dimensional scene or another image. It can be real or virtual. An image may be abstractiy thought of as a continuous function defining usually a rectangular region of a plane. Three types of images are :

Intensity image – an image is typically propotional to the radiant energy received in the electromagnetic band to which the sensor or detector is sensitive.

Range image - an image is a function of the line-of-sight(LOS) distance from the sensor position to the object in the 3-D world.

A recorded image may be in a photographic, analog video signal or digital format. In computer vision, an image is usually a recorded image such as a video image, digital image or

a picture. In computer graphics, an image is always a digital image. In multimedia applications, all formats

can be presented

There are 5 main formats in which to store images.

1. TIFF (also known as TIF), file types ending in .tif

TIFF stands for Tagged Image File Format. TIFF images create very large file sizes. TIFF is the most common file type used in photo software (such as Photoshop), as well as page layout software (such as Quark and InDesign), again because a TIFF contains a lot of image data.

2. JPEG (also known as JPG), file types ending in .jpg

JPEG stands for Joint Photographic Experts Group, which created this standard for this type of image formatting. JPEG files are images that have been compressed to store a lot of information in a small-size file. Most digital cameras store photos in JPEG format, because then you can take more photos on one camera card than you can with other formats.

3. GIF, file types ending in .gif

GIF stands for Graphic Interchange Format. This format compresses images but, as different from JPEG, the compression is lossless (no detail is lost in the compression, but the file can’t be made as small as a JPEG)..

4. PNG, file types ending in .png

PNG stands for Portable Network Graphics. It was created as an open format to replace GIF, because the patent for GIF was owned by one company and nobody else wanted to pay licensing fees. It also allows for a full range of color and better compression.

5. Raw image files

Raw image files contain data from a digital camera (usually). The files are called raw because they haven’t been processed and therefore can’t be edited or printed yet. There are a lot of different raw formats–each camera company often has its own proprietary format.

Color Models:

A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components. When this model is associated with a precise description of how the components are to be interpreted (viewing conditions, etc.), the resulting set of colors is called color space. This section describes ways in which human color vision can be modeled.

RGB color model

– RGB color model, from the first letters of the words “RED”, “GREEN” and “BLUE”.

Thus white color of our dot in RGB color model can be written as:

R – 255, G – 255, B – 255

“Saturated” red can be written as:R – 255, G – 0, B – 0

Black:R – 0, G – 0, B – 0

Yellow will be the following:

R – 255, G – 255, B – 0

You also need to know, that in order to record colors in rgb, we usually use the hexadecimal system. Intensity indicators are recorded in order of #RGB:

White – #ffffff, Red – #ff0000, Black – #00000, Yellow – #ffff00

CMYK color model

White light can be represented as R-255 G-255 B-255. But the thing does not want to reflect all the light that we have sent to it, and it is brazenly stealing from us all hues of green and blue. As a result, it reflects only the R-255 G-0 B-0. That is why it seems to us as red.

So, it is very problematic to use the RGB color model for printing on paper. For printing, as a rule, we use another color model – CMY or CMYK. CMY color model is based on the fact that initially we have a white sheet of paper, and it reflects (virtually) the entire spectrum of RGB, and all inks applied to it, act as filters, each of which “steals” own color (red, or green, or blue). Thus, these color inks are determined by subtracting one from the white colors RGB. We get colors: Cyan (light blue), Magenta (or we can say pink) and Yellow.

As you remember, gradation of each color (in RGB color model) is brightness (from 0 to 255). However, in CMYK color model, the value of each color – is “opacity” (amount of paint) and determines the percentage from 0% to 100%.

Thus, white color can be described as follows:

C (cyan) – 0%; M (magenta) – 0%; Y (yellow) – 0%.

Red: C – 0%; M – 100%; Y – 100%.

Green: C – 100%; M – 0%; Y – 100%.

Blue: C – 100%; M – 100%; Y – 0%.

Black: C – 100%; M – 100%; Y – 100%.

However, this is possible only in theory. But in practice, we can not use CMY colors. Black color turns muddy brown (printing), gray is not similar to the gray, it is problematic to create dark hues.

* Printers often use the word “Contour” on this color. So it is possible that the letter K in abbreviation CMYK – an abbreviation of the German word “Kontur”. Also “Key color”.

*Print using CMYK colors is called “full-color” or “triad.”

We need to note, that during printing, CMYK inks do not mix. They lay down on paper as “spots” (raster) next to each other and mixed already in our’s mind, because these “spots” are very small. That is, the image is rasterized, as otherwise the paint, getting on one another, and spreads produced moire or dirt. There are several different ways of rasterization.

Grayscale color model

Image in grayscale color model many people mistakenly called ‘black and white’. But it is not. Black-and-white image consists only of black and white tones. While both grayscale has 101 hue. This is gradation of Kobalt color from 0% to 100%.

Device-dependent and device-independent color model

Color model CMYK and RGB are device-dependent, ie they depend on the way they transfer a color. They point to a specific device, how to use the corresponding colors, but do not have information about the perception of color of the final person.

To transfer more reliable information about the color to a person, we attach (so-called) color profiles to the hardware-dependent color models. Each of such profile contains information about a particular way of human transmission of color and adjusts the final color by the addition or removal of any constituent of the original color settings.

Example: to print on glossy film uses a color profile, cleaning 10% Cyan and adding 5% Yellow to the original color, because of the specific features of the printing press, the film itself and other conditions. However, even attached profiles do not solve all the problems of transfer color.

Device-independent color models do not contain any information to transfer a color to a person. They mathematically describe color perceived by man with normal color vision.

HSB and HLS color models

The basis of this color space is already familiar rainbow wheel of RGB colorspace. Color is controlled by changing parameters such as Hue, Saturation and Brightness

Parameter hue – the color. Defined by degrees from 0 to 360 based on the colors of the rainbow wheel.

Parameter saturation – percentage of adding to this color of the white paint (has a value from 0% to 100%).

Parameter brightness – the percentage of adding black ink also varies from 0% to 100%.

The principle is similar to one of the representations of the world in terms of art. When we add white or black paint into an existing color.

This is the easiest-to-understand color model, this is thy many web-designers like it very much. However, it has several drawbacks:

The human eye perceives colors ofthe rainbow wheel, as colors with different brightness. For example, spectral green has the greater brightness than the spectral blue. In the HSB color model all the colors of the circle are considered to have a brightness of 100%, which, unfortunately, is not true.Since it is based on the color model RGB, it is still a hardware-dependent.

This color model is converted to CMYK for printing and converted to RGB for display on the monitor. So, it is very problematic to guess what color you get in the long run.

HLS color model is very similar, it has the following meaning: Hue, Lightness and Saturation. This color model is sometimes used for light and color correction in an image

LAB color models

In this color model the color consists of:

Luminance – this is set of notions lightness and chroma

A – this is color range from green to purple

B – this is color range from blue to yellow

That is, the two indicators determine the color (in the aggregate) and one indicator measures the light.

LAB is a device-independent color model, ie it does not depend on how we transfer color. It contains color as RGB and CMYK, and grayscale, which allows it to convert with minimal loss of image quality from one color model to another.

Another advantage is that it, unlike the color model HSB, corresponding to features of perception of color by the human eye.

This model is often used to improve image quality, and converting images from one color space to another.

Image Processing:

There are some fundamental steps but as they are fundamental, all these steps may have sub-steps. The fundamental steps are described below with a neat diagram.

1. Image Acquisition: This is the first step or process of the fundamental steps of digital image processing. Image acquisition could be as simple as being given an image that is already in digital form. Generally, the image acquisition stage involves pre-processing, such as scaling etc.

2. Image Enhancement:Image enhancement is among the simplest and most appealing areas of digital image processing. Basically, the idea behind enhancement techniques is to bring out detail that is obscured, or simply to highlight certain features of interest in an image. Such as, changing brightness & contrast etc.

3. Image Restoration:Image restoration is an area that also deals with improving the appearance of an image. However, unlike enhancement, which is subjective, image restoration is objective, in the sense that restoration techniques tend to be based on mathematical or probabilistic models of image degradation.

4. Color Image Processing:Color image processing is an area that has been gaining its importance because of the significant increase in the use of digital images over the Internet. This may include color modeling and processing in a digital domain etc.

5. Wavelets and Multi-Resolution Processing:Wavelets are the foundation for representing images in various degrees of resolution. Images subdivision successively into smaller regions for data compression and for pyramidal representation.

6. Compression:Compression deals with techniques for reducing the storage required to save an image or the bandwidth to transmit it. Particularly in the uses of internet it is very much necessary to compress data.

Elements of digital image processing systems :

The basic operations performed in a digital image processing systems include (1)acquisition, (2) storage, (3) processing, (4) communication and (5) display.

Image processing software :

Image processing software is software that is designed to manipulate digital images. In particular, it captures the image if that hasn't already been done, it converts it to a digital form, and it performs a manipulation or manipulations on it. For example, have you ever seen someone lighten a photograph that was too dark? Or crop an image to remove unwanted background clutter. These are examples of image processing at work. Its purpose is to improve the contents and quality of an image.

Types of Image Processing Software available:

It seems like there is image processing software for just about any application you can think of. Not surprising really, because it contributes to so many areas. Instead, let's talk about some of the categories, or types, they fall into:

Computer Graphics

We don't often think of computer graphics as image processing because it processes 2D and 3D image definition files rather than the resulting images themselves. It is a fine point, but worthy of note. Examples include maps, posters, videos, and movies.

Computer Vision

This type focuses on processing that helps the software recognize objects within the viewing area. For example, some factories use computer vision to determine if particular steps in their process have been completed successfully.

Medical Imaging

This type focuses on processing that helps with issue detection and diagnosis. Examples include; Bioimaging (non-invasive visualization of biological processes) and Neuroimaging (visualization of the nervous system).

Photo Editing

This type focuses on processing that helps improve photographs, like changing the brightness, contrast, or color skew. For example, when you brighten an overly dark photograph or crop out background clutter.

Freeware Software To Operate GLCF Products ArcExplorer, by ESRI MODIS Reprojection Tool, by USGS-NASA

Multispec, by Purdue Research Foundation

GZIP, by Jean-loup Gailly and Mark Adler

Software to Utilize Satellite Imagery

(Note: these are not endorsed by the GLCF, just listed as a resource)

Image Processing software Geomatica, by PCI Geomatics ENVI&IDL, by Research Systems, Inc.

ER Mapper, by Earth Resource Mapping

Imagine, by Leica

Msphinx, by the University of Lille (free!)

Image Processing Workbench (IPW), by USDA ARS - USGS eCognition

Hierarchical Data Format Display Software, by Earth Remote Sensing Data Analysis Center

PixelSense, by AlphaPixel

Idrisi, by Clark Laboratories

Imagery-capable GIS software ArcGIS, by ESRI ArcView GIS, by ESRI

GRASS GIS, by freeware

Idrisi, by Clark Laboratories

GeoMedia, by Intergraph Mapping/GIS

MGE GIS, by Intergraph Mapping/GIS

MapInfo GIS, by MapInfo

Manifold System, by manifold.net

3D graphics software (11 C, 256 P) 3D computer graphics software for Linux (3 C, 13 P) Anatomical simulation (31 P) 3D animation software (31 P) AutoCAD (6 P) Free 3D graphics software (66 P) Freeware 3D graphics software (11 P) Global illumination software (30 P) Photogrammetry software (5 P) Rendering systems (19 P, 1 F) RenderMan (5 P)

Shading languages (9 P)

Bioimaging software (4 C)

DICOM software (1 C, 2 P) Facial recognition software (8 P) Free bioimaging software (1 C, 10 P)

Neuroimaging software (22 P)

Computer vision software (1 C, 48 P)

Photogrammetry software (5 P)

Neuroimaging software (22 P)