Image and Sound Processing, Networks, and Digitalization

Image Processing

Imaging Technique

• Bitmap (Raster): Formed by pixels, each with a color. Programs: GIMP, Photoshop. Formats: GIF, JPEG, BMP, TIFF, PNG, PCX (Paintbrush), RAW, TGA, PSD (Photoshop), XCF (GIMP).
• Vector: Obtained using lines. Programs: Corel Draw, OpenOffice.org Draw, AutoCAD, QCad. Formats: DXF, CDR, DWG, ODG/SXD, SWF, AI, SFHx.
• 3D: Three-dimensional figures. Widely used in games. Programs: Virtual Hammer.

Memory Cards

• SD
• MMC
• XD
• Memory Stick

Image Properties

• Color Depth: Total number of bits used to encode an image. More depth means more shades.
• Brightness: Related to light intensity emitted over a given area.
• Contrast: Brightness difference between the maximum and minimum brightness.

Color Specification Systems

• RGB (Red, Green, Blue): Used in photos, videos, monitors, TVs. Other colors can be derived from these.
• CMYK (Cyan, Magenta, Yellow, Black): Used for printing. Called subtractive colors.

Networks

Network Types (Size)

• LAN (Local Area Network): Home network with printer, hard drive, etc.
• WAN (Wide Area Network): Network between cities or countries (e.g., the internet).

Network Types (Access)

• Internet: Global public network.
• Intranet: Private network within an institution.
• Extranet: Interconnected intranets.

Sound and Digitalization

Sound Properties

• Sound: Analog wave energy.
• Analog Signal: Signal within a certain range.
• Digital Signal: Signal with discrete values.
• Sample: Discrete value at a certain time.
• Sampling: Sampling the signal periodically.

Physical Layer

• Deals with physical elements (cables, network cards).
• Network Card (NIC): Integrated or separate.
• Ethernet: RJ-45 port.
• Wi-Fi: Wireless connection.

Cables

• Twisted Pair: Slow, cheap, 10-100 Mbps.
• Coaxial: Intermediate between twisted pair and fiber optic.
• Fiber Optic: Fast, expensive, 155+ Mbps.

Interconnection Elements

• Hub: Basic, used in small networks.
• Switch: Sends information to the recipient computer.
• Router: Configures network addresses and connects networks.
• Access Points: Wireless hubs or switches.

Network Topologies

• Star: Most common, direct connection to a central hub.
• Bus: Computers share a line.
• Ring: Cyclical connection.

Sound Digitalization

• Resolution: Number of bits per sample.
• Frequency: Wave repetitions per second.
• Digitalization: Converting analog sound to digital.