2The Development Process and Multimedia Applications The Software Development Process and Multimedia ApplicationsAnalysis: The main purpose of this stage is to be absolutely clear about what the multimedia project is supposed to do.
3The Development Process and Multimedia Applications Design: Producing a detailed plan which defines what the different parts of the project are and how they are linked together.
4The Development Process and Multimedia Applications The Software Development Process and Multimedia ApplicationsImplementation: This is the point at which the multimedia authoring, or web-page authoring, package is used to turn the design into a working project.
5The Development Process and Multimedia Applications The Software Development Process andMultimedia ApplicationsTesting: A series of practical tests are carried out to check that the multimedia project functions properly.Documentation: User Guide and Technical Guide.
6The Development Process and Multimedia Applications The Software Development Process andMultimedia ApplicationsEvaluation: Checks that the finished application meets the user’s requirements. Includes an assessment of the HCI design.Maintenance: Fixing bugs and adapting the design to suit client needs and the demands of new technology.
7Methodologies used in creation of multimedia applications Text editor: Creating simple web pages using HTML.WYSIWIG editors: Previewing applications under development to check that what you see is what you get.Multimedia authoring packages, e.g. Mediator Pro.Presentation software, e.g. PowerPoint.
8Methodologies used to view multimedia applications Displaying multimedia applications in a browser.Displaying multimedia applications using a file player or viewer.
9Methodologies used to view multimedia applications Multimedia application as an executable file
10Bit-mapped Graphic Data Capturing still images using a digital cameraUsing a CCD to capture light coming in through a lensCCD charged coupled device: uses sensors to capture lightCapturing images using a scanner: also uses CCD
11Bit-mapped Graphic Data Storing graphics as a bit map: each pixel in the image is represented by a binary number.Uncompressed bit-map format: a file which holds a binary number for each pixel in an image.Large file size: main limitation of bit-map format.Need for compression: to relieve demands on storage and transmission times.
12Bit-mapped Graphic Data Compression using GIF formatLossless compression: GIF format compresses graphic data without losing any information about the image. It compresses by encoding repeated patterns of data.Limited number of colours: limited to 28, 256 colours.Transparency: colours set as transparent let the background colours and patterns show through.Used for storing cartoons, and line drawings.
13Bit-mapped Graphic Data JPEGUses lossy compression: parts of the graphic are cut out, e.g. shades of colour. At low rates of compression this is not noticeable.
14Bit-mapped Graphic Data JPEGJPEG format suitable for storing photographsand paintings.
15Bit-mapped Graphic Data Trading quality for file sizeResolution: increasing resolution increases the number of pixels, can improve the quality of a graphic but increases the file size.Colour depth: increasing colour depth increases the number of colours or shades of grey, can improve the quality of a graphic but increases the file size.Lossy compression: reduces file size and, providing the rate of compression is not too high, does not affect the quality of the graphic.
16Bit-mapped Graphic Data Simple bit-map editing and creation softwarePainting programsFill tool: a feature for pouring colour into a graphic.Paintbrush tool: for more precise application of colour.
17Bit-mapped Graphic Data Main features of image editing programsDecrease resolutionAlter colour depthCropAlter brightness and contrastInsert graphicRe-size.
18Bit-mapped Graphic Data Hardware for displaying 2D graphicsCRT monitor: bulky, heavy, run on mains power, cost less than equivalent TFT screens.LCD and TFT screens: flat, light, need less power, more expensive than CRT.
19Bit-mapped Graphic Data Hardware for displaying graphic dataNeed for graphics cards to store and process graphic data, relieving the main processor of the task.
20Hardware for capturing sound Digitised Sound DataHardware for capturing soundMicrophoneSound cards: to sample, store and process audio data.
21Uncompressed sound data Digitised Sound DataUncompressed sound dataRAW: Uncompressed samples of sound wavesRIFF: Resource Interchange File FormatWAV: Microsoft's format for sound files, part of RIFF
22Digitised Sound DataLossy compression: reduces file sizes by cutting out some of the data.MP3: uses lossy compression without noticeable loss of sound quality.
23Balancing file size and sound quality Digitised Sound DataBalancing file size and sound qualitySampling depth: increased sound depth = greater range of values = better sound quality and greater file size.Sampling frequency: The higher the sampling frequency, the better the sound quality, the greater the file size.Sound time: affects file size but not quality.
24Simple sound editing software Digitised Sound DataSimple sound editing softwareReducing sample frequency, e.g. from 44.1 KHz to KHz, reduces file size and audio quality.Reducing sample depth, e.g. from 16 bits to 8 bits per sample, reduces file size and audio quality.
26Digitised Sound Data Sound cards and playback: Sound cards needed to change the digital audio data into analogue signals to control output from speakers.
27Hardware for capturing images Video DataHardware for capturing imagesDigital video cameraWeb cam
28Video Data Storing video data Uncompressed format Uncompressed video data = Large file sizes1 second of uncompressed wide-screen video can take up 53 Megabytes of storageAVI: Audio Visual Interleave, an uncompressed format.
29Compressing video data MPEG-2Lossy compression: cuts out unnecessary parts of a video clip
30Compressing video data Using MP3 compression:Reduces file sizesWith no noticeable loss of video quality.
31Video quality and file size Video DataVideo quality and file sizeColour depth: increasing colour depth improves quality and file sizes.Resolution: increasing resolution improves quality and increases file sizes.Frame rate: measured in frames per second, fps. 30fps is the rate for a video clip. Increasing frame rate increases file size. Lower frame rates reduce file size but make video clip ‘jerky’.
32Video quality and file size Video DataVideo quality and file sizeVideo time: increasing or reducing the time of a video is the obvious way to affect the file size. Quality of the display of the clip is not affected.Lossy compression: Using MP3 compression reduces file sizes without affecting quality.
33Video DataVideo editing software features and applications used with single video clipsCropping: cutting unwanted data from the beginning and end of a clip.Add effects, titles, sound tracks.The need for graphics cards to process and output video data.
34Basic features of vector graphics Vector Graphics DataBasic features of vector graphicsThey are scalable: resolution independent.In a vector graphic individual objects can be edited.Graphics can be assembled by placing objects in layers.
35Vector Graphics Data Common attributes of vector graphic objects PositionShapeSize
36Vector Graphics Data Common attributes of vector graphic objects RotationLineLayerFill
37Vector Graphics Data Attributes of a 3D image Shape Position Size RotationTexture
38Standard formats for vector graphics Vector Graphics DataStandard formats for vector graphicsScalable Vector Graphics (SVG) formatScalable: resolution independentVector: represents objects by defining a series of attributes
39Standard formats for vector graphics Vector Graphics DataStandard formats for vector graphicsVirtual Reality Markup LanguageA standard language used to model and animate geometric shapesUsed to define 3D environments for the WWW.
40Synthesised Sound Data Musical Instrument Digital Interface: MIDICommon attributes of notes stored as MIDI data:Instrument: defines which instrument is playingPitch: defines the height of the noteVolume: determines the amplitudeDuration: determines the length of the note.
41Synthesised Sound Data Common attributes of notes stored as MIDI dataDuration: determines the length of the note.Tempo: the speed at which a piece of music is played.
42Implications: Multimedia Technologies Converging contemporary technologiesSmartphone: merging technologies of a mobile phone and a laptop.Pocket PC: merging technologies of a laptop, mobile phone and desktopoperating system and applicationsoftware.
43Implications of Multimedia Technologies Contemporary technologiesDigital television: an interactive multimedia device which, because of the digital nature of its signals, is easily integrated into your digital computer and home networks.
44Implications of Multimedia Technologies Contemporary technologiesVirtual realityThe ultimate multimedia experience where the user is immersed in the world of the computer and can journey through, and interact with, a computer generated 3-dimensional multimedia world.
45Implications of Multimedia Technologies Immersive VROutput :Using speakers, stereo screens, headsetsInput: sensors in gloves, headsets and suits