Multimedia Systems Flashcards
Online form - typical fields
- Input fields:
- text fields
- password fields
- checkboxes
- radio buttons
- sliders - Action buttons:
- radio button
Colour depth
Number of bits per pixel:
The more the colour depth, the more bits required to produce the image and thus more image file size. The more the colour depth, the more colours the image includes.
Cell based vs. path based animation
Cell based:
- the whole clip is fully animated
- images are each produced in a separate “cell”
- each frame is individually animated
- have higher frame rates (30 fps)
- requires more processing power to work
- display of the clip will be smoother and fluid
Path based:
- usually only the foreground is animated with a still background
- lower frame rate (24 fps)
- do not require that much processing power
Compression processes - images
- lossy - alters the image (image quality loss)
- lossless - does not alter the image (no image quality loss)
- JPEG compression technique - blur hard edges of an image - lossy compression but tries to minimise the loss of quality ( :) )
Compression/Decompression processes video
- CODEC –> coder decoder
software that compresses and decompresses digital video to make the file size smaller using appropriate CODEC to compress or decompress videos - Block based coding –> frames are split up into a series of forms
VR applications (list and explain : ) )
- head-sets/heads-up display
- virtual worlds - education and training
AI and ethics in multimedia
- artists on the internet → issue of copyright, artists work can be placed into AI and manipulated
- deliver biassed results
- privacy of the data collected on individuals
- AI taking over our jobs
- changing our interactions and behaviour at work
Morphing
One image is slowly faded/changed, pixel by pixel, until the second image emerges
Distorting
Pixels of an image are changed by stretching or resizing so the image results in a different form
Expertise in Multimedia systems (list)
- project managers
- system developers
- system designers
- content providers
- writers
- graphic designers
- illustrators and animators
- technical personnel
Print vs Multimedia
- different modes of display
- interactivity provides user with a better experience
- involvement of participants
- ease of distribution
- authority of document
Roles and skills required by a system designer
- oversee development in terms of the stages of system development
- plan and organise hardware and software
- preparing specifications
- require communication skills, management skills, skills in producing the system
Roles and skills required by content providers
- provide the content for the multimedia (content = media in the display)
- experts in the subject matter of the project
- require skills in software to produce content
How does a CRT screen work to display multimedia
- electron beams are ejected to produce the colour on the display by making the phosphor glow
- inner screen of the monitor is coated with phosphor that emits the light in the three primary colours
How does a LCD screen work to display multimedia
- LCD’s are lit by a backlight
- pixels are switched on and off electronically while using liquid crystals to rotate polarised light
Why are multimedia systems used?
to provide a more realistic and immersive environment for individuals (typically multimedia systems that use VR)
How have advances in processing power influenced the development of multimedia systems?
–> faster CPU –> more interactive media and higher resolution displays
–>improved bandwidth –> allows streaming to multiple devices
–> powerful CPU–> faster compression and decompression–> developers can use more elements in the display
–> need for larger storage devices with faster access to store and retrieve data
What is a pixel?
The smallest unit of an image that can be displayed and represented on a digital display device
Describe animation
a rapid display of a sequence of images to create an illusion of movement. frame rates of about 24fps are needed to create this illusion
ROM and RAM
ROM - read only memory –> holds data that are fixed at the time of construction, is non-volatile
RAM - random access memory –> data and instructions are held temporarily, is volatile and relies on power to maintain its contents
Bit mapping
relationship between the image on screen and the bits stored in primary and secondary memory
- each pixel is described by one or more bits in memory
Sampling Size
number of bits used to stored each sample from the analog sound wave
Sampling rate
number of samples taken of the analog wave in 1 second
Multimedia used in leisure and entertainment
allows for ingenious levels of interactivity and realism to captivate users of the product. here, the multimedia has realism, fast action and user input
- requires high level of graphics computing power
Raster Scan in a CRT display
- phosphorus must be re-excited to maintain images in CRT display
- electron beams start from the top left-hand corner and move left to right and top to bottom in a zigzag pattern which is called a raster scan
