Multimedia Option

Question 1

Contrast vector and bitmapped graphics

Answer 1

“Vector graphics are created using mathematical formula and are scalable. Bitmapps are created using pixels”

Question 2

Explain how vector images are stored

Answer 2

“Vector images are stored using mathematical equations (co-ordinates). This means that when they are resized”

Question 3

Explain how bitmapped images are stored.

Answer 3

Bitmapped graphics are stored by storing individual pixels (dots) which make up an image._Ä©

Question 4

Give examples of where bitmapped images would be best used?

Answer 4

Photographs!_Ä©

Question 5

Explain how resolution affects an image.

Answer 5

“Resolution is essentially an images QUALITY. Resolution is the number of pixels in an image”

Question 6

Define Bit depth

Answer 6

Bit depth is the number of bits required to represent each pixel. We know that: 2^bit depth = number of colours. Also known as colour depth._Ä©

Question 7

Define colour depth

Answer 7

Colour depth is the number of bits required to represent each pixel. We know that: 2^bit depth = number of colours. Also known as bit depth._Ä©

Question 8

How do you calculate the file size of an image?

Answer 8

Resolution * Bit depth /8 * 1024

Question 9

Describe features of TIFF Files

Answer 9

widely supported bitmap format, good with photographic as well as line art graphics (kind of the best of both worlds between jpeg and gif. Can be compressed a little, but not too much. generally about 10 x the file size of the equivalent sized jpeg.

Question 10

Describe features of BMP Fiels

Answer 10

Uncompressed, good quality files. Generally just used in windows systems.

Question 11

Describe features of PCX/PICT Files

Answer 11

An older format, that used to be the standard for graphic design. this has been surpassed by other, more standardised file formats.

Question 12

Describe features of JPEG files

Answer 12

Lossy compression, averages out values of colours near each other to create common areas of colours. Good for photos. Standardised. Does not support transparency, or animation.

Question 13

Describe features of GIF files

Answer 13

Good for fine line drawings, cartoons, maps, etc. Bitmapped format, but good compression, as uses lossless compression, where quality is restored on extraction. Gif is an 8 bit file format (256 colours) which supports transparency and animation.

Question 14

Describe features of PNG Files

Answer 14

Good for fine line drawings, cartoons, maps, etc. Bitmapped format, but good compression, as uses lossless compression, where quality is restored on extraction.

Question 15

Define anti-aliasing

Answer 15

Anti-ailiasing gives the illusion of a higher quality as it may smoothen edges of an image. However anti aliasing takes more to process (graphics card has to do more work) and may worsen the quality (as it is blurrier) on projects that are intended for printed.

Question 16

Describe features of WMA

Answer 16

WMA files are Windows Media Audio files as these files are optimised for the windows operating system, which may be a negative when a user wants to use it on an apple system (as they need a different codec/program). These files have a low compression and therefore have a higher quality and file size when compared to files such as .mp4.

Question 17

Describe features of midi files

Answer 17

MIDI (Musical Instrument Digital Interface) files are audio. These files store the sound with formulae, and therefore they may be more easily edited and manipulated by users.

Question 18

How is a sound file stored in memory

Answer 18

This involves taking a number of samples or Ä_Ù´ÄãslicesÄ_Ù´Ä_ of the sound wave. This is called the sampling rate (Samples per second). Each sample is assigned a number of bits. This is called the sample size (or bit rate). Better quality sound is achieved by increasing the sampling rate and/or the sampling size. These co-ordinates then define the curve that the shape follows. The more of either of these elements, then the greater quality of the curve, therefore the better quality sound.

Question 19

Define Sampling

Answer 19

Sampling is the process of digitising sound by taking samples of the sound wave in order to correctly map the co-ordinates of the curve that defines the wave.

Question 20

Describe features of AIFF Files

Answer 20

AIFF is an apple based format that is used to store sound files. AIFF itself is uncompressed, but has variants that are compressed using certain codecs. It is high quality, and a higher file size than say, MP3.

Question 21

What is the difference betweenMIDI file and a sound file?

Answer 21

A midi file is a programmed sequence of sound that is generated from the sound card, which plays sounds in a particular sequence. Sound files, however are simply recordings of sound, and are typefied by wave files.

Question 22

What considerations are thereregarding file size of a video?

Answer 22

Frames per second, resolution, length, bit depth

Question 23

Define:Ä_Ù´û˜ LossyÄ_Ù´û˜ Lossless

Answer 23

Lossy is compression where data is thrown out and it is not restored on decompression. Lossless data is restored on decompression, so that there is very little loss in quality.

Question 24

Describe features of MPEGFiles (video)

Answer 24

Good compression ratio, highly standardised.

Question 25

Describe features of AVI Files

Answer 25

Uncompressed, good quality.

Question 26

What is the difference betweena transition and an effect invideo files?

Answer 26

Transitions occur between two clips (eg, fade in and out) and effects occur on top of the film (eg, colour correction)

Question 27

What is cel animation?

Answer 27

Traditional hand made animation. Frame by frame, each drawing is done on a frame (traditionally, celluloid) and pieced together to create the illustion of movement

Question 28

What is path based animation?

Answer 28

Path based animation is where animation follows a particular sequence. (eg, a plane flying across the screen)

Question 29

What is morphing? Giveexamples.

Answer 29

Morphing involves converting one image to another. Remember Michael Jackson's Black or White.

Question 30

What effect does Frame Ratehave on an animation?

Answer 30

It effects the speed and smoothness of movement. Higher frame rates mean a smoother animation. It also effects the file size aas there are more frames per second.

Question 31

What is modelling in 3DAnimation?

Answer 31

Creating the figure. Imagine modelling in clay. Essentially the same process

Question 32

Distinguish between warping and morphing

Answer 32

Warping is taking one image and altering it, pushing and pulling it around. Eg, you could make your ears look really big. Morphing is between two images.

Question 33

How does motion capture work

Answer 33

Motion capture works by placing coloured dots all over an object and videoing this, and mapping this against an animation. This was done with the movie Lord of the Rings (the best movie in the world) for the character of Gollum.

Question 34

Give advantages of progressively loading images

Answer 34

These can be put on a website so that the website appears to load quicker (kind of like on facebook photos) where the images load quickly in low res by alternating downloaded lines of pixels, and then clarify over time.

Question 35

What are thumbnails

Answer 35

Preview images shown on a website (think google images)

Question 36

What is streaming

Answer 36

The transfer of video so that it can be watched while the transfer occurs (as opposed to downloading where you have to wait for the whole thing.

Question 37

Compare/Contrast two forms of video transfer

Answer 37

Video transfer types are RTSP and HTTP: RTSP allows live streaming and is good on mobile devices. HTTP is traditional streaming. An advantage of HTTP is that you don't have to restream after you have viewed components. With RTSP, it progressively downloads, then throws away any data that it has streamed in order to save space on your device. This means you have to restream in order to rewatch.

Question 38

How does buffering work

Answer 38

Buffering is where in a video download process, a small part of the video is downloaded ahead of where you have watched, and saved in the RAM so that you can watch the video more quickly

Question 39

How is an image file stored?

Answer 39

Each individual pixel is mapped in memory, in terms of it's location and colour. The number of pixels * amount of bits used per pixel (bit depth) is the file size

Question 40

What is sampling

Answer 40

A process where sections are taken of a sound file in order to digitise it.