comp sci 3

logic gate

A little machine that decides yes/no using 0s and 1s.

transistors

Tiny switches that turn electricity on/off.

NOT gate

Flips the input! (0 becomes 1, and 1 becomes 0)

AND gate

Only gives 1 if both inputs are 1.

OR gate

Gives 1 if at least one input is 1.

XOR

Gives 1 if only one input is 1 (not both).

truth table

A list of all possible input combinations and their outputs.

half adder

A circuit that adds two bits and gives sum + carry.

full adder

Adds two bits and a carry bit. Gives a new sum + carry.

4-bit adder

A bunch of adders working together to add bigger numbers.

microphone

A transducer that converts sound waves (analog) into electric signals (digital).

speaker

Converts electric signals into sound waves.

sine wave in audio

A mathematical function representing pure tones: S(t)=asin(2πft−θ)

amplitude

Loudness or intensity, measured in decibels (dB).

frequency

Pitch, measured in Hertz (Hz).

Nyquist-Shannon sampling theorem

To capture all info, the sampling rate must be at least twice the highest frequency (fs≥2f).

bit depth in audio

The number of bits used per sample, affecting dynamic range and accuracy.

bit rate formula for digital audio

Bit Rate = Bit Depth × Sampling Rate × Number of Channels.

CD-quality audio

16-bit depth, 44.1 kHz sampling rate, stereo (2 channels), 1.4 Mbps bit rate.

lossless audio compression

Preserves original data exactly.

lossy audio compression

Removes imperceptible details to save space.

lossless audio codec

FLAC - uses LPC and Rice coding.

lossy audio codecs

MP3 and AAC - use psychoacoustic models and Huffman coding.

primary colors in RGB model

Red, Green, Blue.

typical range for RGB values

0 to 255 for each channel.

color representation in hexadecimal

As #RRGGBB, e.g., (178,102,255) = #B266FF.

CMYK color

Used for printing - Cyan, Magenta, Yellow, and blacK on white paper.

pixel

A single dot of color in a digital image.

image resolution

The number of pixels in width × height (e.g., 1920x1080).

raster graphics

Images made of pixels (bitmaps), good for photos.

vector graphics

Images made from mathematical equations; scalable without losing quality.

vector image format

SVG (Scalable Vector Graphics).

indexed color

Technique that uses a color palette to reduce file size by referencing only used colors.

GIF

Best used for simple animations, line drawings - supports transparency.

PNG

Best used for lossless compression; good for diagrams and logos; supports transparency.

JPEG

Best used for photographs; uses lossy compression, not good for sharp lines or text.

JPEG compression

Works by breaking image into 8×8 blocks, stores average intensity and pixel differences.