AP Comp Sci unit 1

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.

Sampling

A process for creating a digital representation of analog data by measuring the analog data at regular intervals called samples.

Convert 118 to binary

0111 0110

Flippy do order bases

256 128 64 32 6 18 4 2 1

Convert 101101 (base-2) to decimal.

45

Byte

8 bits

Binary

A base 2 number with two possible different digits , 0 and 1

Bit

A contraction Binary Digit"; the single unit of information in a computer, typically represented as a 0 or 1

What is abstraction and how does it relate to how computers store information?

Abstraction is creating simplified representations of something more complex. Computers use abstraction to reduce complexity and increase efficiency.

How does a Creative Commons license differ from a regular copyright?

Copyright grants authors the exclusive rights regarding the use and reproduction of their original work Creative Commons license gives the creators the freedom to decide which rights are being reserved and which are waived.

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.

Round off error

Error from attempting to represent a number that is too precise. The value is rounded.

What is the difference between analog and digital? Provide an example from your life where you have both a digital and analog version of something.

Examples: clock, Analog— Data with values that change continuously, or smoothly, over time Digital— Data that changes discreetly through a finite set of possible values

Would you rather own a camera (or phone camera) with a higher or lower number of megapixels? Why?

Higher megapixels = better quality but more storage space Lower megapixels = not as clear photos, less storage space

What is the difference between lossy and lossless compression? What are the tradeoffs for each?

Lossy compression can significantly reduce file size (smaller than lossless) but that also means there is quality loss. You also cannot get your original back after compressing with lossy compression. Lossless compression— A process for reducing the number of bits needed to represent something without losing any information. This process is reversible. 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.

Intellectual property

Materials you create on the computer. You own them - you have copyright to them as the creator.

If person A creates an image with a Creative Commons license. Person B then uses the image on his website. Who owns the image and why? (L11)

Person A owns the image and has given permission for the image shared, reused or remixed through the CC license(

Why do rounding errors occur? Give an example (not from notes).

The tools that we use to represent numbers have limitations. Measure exact speed, time.

Creative Commons

license that indicates which part of your copyright you would allow to share with public for use.