AP Comp Sci Digital information

Analog vs. Digital

-Analog: reproduces an approximation of the sound wave -Digital: reproduces an approximation, then converts it into code; no degradation or generation loss during digital editing

kilobyte

1024 bytes

terabyte

1024 gigbytes

megabyte

1024 kilobytes

gigabytes

1024 megabytes

petabytes

1024 terabytes

byte

8 bits

unicode

A character code that enables most of the languages of the world to be symbolized with a special character identification. Extended ascii method. Allows for different languages and all kinds of flexible characters such as emojis.

innovation

A new improved idea, device or product

Lossy Compression

A process for reducing the number of bits needed to represent something in which some information is lost or thrown away. This process is NOT reversible.

Lossless Compression

A process for reducing the number of bits needed to represent something without losing any information, This process is reversible

bit

A unit of information expressed as either a 0 or 1 in binary notation (one column in the floppy do)

INtellectual Property

A work or invention that is the result of creativity to which one has rights

hexadecimal letter

A=10 B=11 C=12 D=13 E=14 F=15

roundoff error

The difference between the calculated approximation of a number and its exact mathematical value.

b, c

Assume your friend just sent you 32 bits of pixel data (just the 0s and 1s for black and white pixels) that were encoded after sampling an image. Choose the two statements that are true. a.The 32 bits of pixel data is enough to produce the image using the widget. Nothing else is needed. b.The correct width and height must be input into the pixelation widget to produce the image. c.The fact that only 32 bits were used to represent the image indicates relatively large sample squares were used. The digital image may vary from the analog image significantly. d.The digital image would be an exact copy of the analog image.

binary

Base 2 number system, represents numbers with 0's and 1's

digital data

Data that changes discreetly through a finite set of possible values

analog data

Data with values that change continuously, or smoothly, over time. Some examples of analog data include music, colors of a painting, or position of a sprinter during a race.

overflow error

Error from attempting to represent a number that is too large.

c

How is a Creative Commons license different from a regular copyright? It is different in name only - in practice, it does the same thing. It allows others to share and reuse your work if they pay you first. It allows your work to be shared, reused, and remixed to help spark more creativity. It is the most restrictive type of copyright, not allowing anyone to use your work for any reason.

copyright

It protects your IP and keeps anyone from using it, unless you give permission

Open access

Online research output free of any and all restrictions on us, such as copyright or license restrictions

pixel

Picture element-basic unit of digital image: represents a single color level of brightness 0=black pixel 1=white pixel

Open source

Programs made freely available for anyone to use and may be redistributed and modified

Creative commons license

Provides free license that you can use to tell other what they can and can not do with your IP

hexadecimal

Relating or using a system of numerical notation that has 16 rather than 10 as a base

Octal

Relating or using a system of numerical notation that has 8 rather than 10 as a base

sampling

Sampling is the process of taking examples of equal size from an analog image and determining the value used to represent the sample in this case black or whit

how does binary work

Using a number system that is based on the power of 2. uses 0 and 1's

a

What is the most important quality of lossless compression? The data is transformed to usually make it smaller. It can always be re-constructed back to the original. The data is transformed to always make it smaller. It can always be re-constructed back to the original. The data is transformed to usually make it smaller. It cannot always be re-constructed back to the original. The data is transformed to always make it smaller. It cannot always be re-constructed back to the original.

B

Which of the following would result in a better digital approximation of an analog black and white image? a.Increasing the size of each sample square, thus decreasing the number of samples taken. B.Decreasing the size of each sample square, thus increasing the number of samples taken. c.Using fewer bits to represent the image. d.Using decimal numbers to represent each pixel.

b

Which statement about analog and digital images is true? a.With advances in technology, digital images look exactly like the analog images they represent. b.Sampling an analog image more frequently produces a digital image with a better representation. c.Analog images come from data that is measured at regular intervals. d.Digital images come from data that is measures continuously.

ASCII

a code for representing English characters as numbers, with each letter assigned a number from 0 to 127 American standard code for information interchange symbols 0-31 and 127 are reserved for control characters like backspace and delta while 32-126 were used for printable characters

order of storage

bit, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte

texts, emails, audio

lossless compression examples

images and videos

lossy compression examples

bit, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte

order

RGB

the RGB color model uses varying intensities of (R)ed, (G)reen, and (B)lue light are added together in to reproduce a broad array of colors. Red green and blue Uses 3 bits