multimedia

Question 1

define vector graphics

Answer 1

images made up of drawing objects, the properties of each object determines its shape and appearance

Question 2

define bitmap images

Answer 2

images stores as an array of individual pixels

Question 3

what is pixel?

Answer 3

smallest picture element

Question 4

what is image resolution

Answer 4

measured in pixels per inch, this value determines the amount of details an image has.
higher image resolution means that there are more pixels per inch resulting in more pixel information and creating high quality images

Question 5

what is screen resolution?

Answer 5

number of pixels which can be viewed horizontally and vertically on a screen

Question 6

what is color depth/bit depth

Answer 6

number of bits allocated to represent each pixel’s color

Question 7

what is metadata

Answer 7

data about data eg:-filename, file format, color depth.

Question 8

what is file header

Answer 8

contains information regarding the image such as its file size, number of pixel ,type of compression, color depth , file location.

Question 9

how images are encoded into a digital format?

Answer 9

• the images are stored as bitmap images
  -each image is made up of pixels
  -each pixel is of a single color
  -each color has a unique binary number
  -sequence of each binary number is stored of each image

Question 10

features of graphics editing software

Answer 10

re-size- increase/decrease the size of the image
crop-remove certain part of the image
blur- reduce the focus
red- eye reduction- reduces red light reflected from human eye

Question 11

what are the features of vector graphics

Answer 11

– vector graphics store a set of instructions about how to draw the shape .
–can be enlarged without the image being pixelated
–do not compress well
–individual elements of vector graphics can be grouped
–suitable for more geometric shapes

Question 12

benefits of using vector graphics

Answer 12

– can resize it without pixalation
–images are redrawn with each adjustment
–smaller file size
– storing commands, not individual pixels
–can be transferred quicker and download quicker

Question 13

define property ,drawing list , drawing objects

Answer 13

property: data about the shapes
drawing list: the list of shapes involved in an image
drawing objects: the object made with different shapes

Question 14

how to calculate file size

Answer 14

size: (width pixels)(height pixels)(color depth)
{units = bits}

Question 15

define digital data

Answer 15

data that has been stored as binary value which can be either 0 or 1

Question 16

define analogue data

Answer 16

data obtained by measurement of physical property which can have any value from a continuous range of values.

Question 17

define sampling

Answer 17

taking measurement at regular time interval

Question 18

define sampling rate

Answer 18

the number of samples taken per second

Question 19

define sampling resolution

Answer 19

the number of bits used to store each sample

Question 20

how sampling is used to record the sound clip

Answer 20

– the amplitude of the sound wave is determined
–at set time interval
–to get an approximation of the sound wave
–encode as a sequence of binary numbers
–increasing the sampling rate will improve the accuracy of the recording

Question 21

what is quantization error

Answer 21

quantization error is the difference between the analog signal and the closest digital value at each sampling instant