Data Representation Flashcards

Question

What is metadata?

Answer 1

Information about the file, eg date of file/ size of file code

Answer 2

Small squares of colour that make up a bitmap image. Too small for the human eye to see so it appears as though the colours are merged together. Each pixel is represented by a binary number

Answer 3

The number of bits used for each pixel Total colours= 2^n (n= colour depth) Measured in bits per pixel

Answer 4

The number of pixels in a specific area of an image Width ✖️height The higher the resolution, the more pixels and the better the quality is.

Answer 5

Image: | In bytes= (resolution *colour depth)/8

Answer 6

Recorded analogue signal stored digitally | SAMPLING the amplitude of the wave at regular intervals

Answer 7

The number of samples taken per seconds, measured in hertz. Higher sample rate means higher quality

Answer 8

The number of bits used to record each sample. Increasing this will help pick up more background noises , therefore making or sound closer to the original (increases quality)

Answer 9

The measure of how much data is processed for each second of sound Bit rate= sample rate * bit depth

Answer 10

Bytes | = sample rate✖️sample resolution ✖️length (seconds)➗8

Answer 11

Normal what is recorded by the microphone. | A continuous signal, which can’t be processed by a computer. Therefore must be converted into electrical.

Answer 12

Taking samples of the of the amplitude of the wave are taken at regular intervals and stored as a binary value.

Answer 13

The method is reducing file size , while trying to make the compressed file s true to the original as possible.

Answer 14

Sample rate: will increase the quality as it will match more closely to the original recording. Sample resolution: will pick up more quieter sounds, resulting in a smaller sound that is closer to the quality of the original.

Answer 15

0️⃣smaller files take up less storage on a device 0️⃣streaming and downloading files from the internet is quicker as they take up less bandwidth 0️⃣allows web pages to load more quickly into web browsers 0️⃣Emails have restrictions on size, but with compression you can send attachments

Answer 16

Permanently removing data from the file , to limit the number of bits the file needs , therefore reducing space. ✅less bandwidth ✅reduce a lot of file size ❌cannot be used on text or software files ❌cannot regain original file , but the worse quality is normally unnoticeable MP3 , AAC ,JPEG

Answer 17

``` Data is removed temporarily, so reduction in quality. then restores to it’s original state ✅can be Used for software and text files ❌only slight reduction in file size FLAC, TIFF, PNG ```

Answer 18

Lossless data compression 1. Make a frequency tally for the amount of times a letter was used 2. Order it from lowest to highest 3. put the two lowest together and addd the Total, keep on branching off until all the values are done. 4. Zeros on the left hand side 5. On the chart add the new binary values

Answer 19

Times the frequency by the amount of bits used to represent the character and add the total. Compare this to the previous amount of total characters ✖️ 7

Answer 20

Another form of lossless compression 1. Count the number of times the same data is repeated and store this instead 2. Store the information as data pairs (Number of pixels, colour) Times number by 8 and colour by colour depth and add it all together 3. Compare this to the previous by timing width and height of pixels by colour depth.

Answer 21

A form of lossless compression, | Looks for runs of data and stores the number of times data is repeated and one copy of the data as a data pair.