Representing Images, Audio and Video
Digital media represents visual and sound information as finite binary values.
Summary
Digital media represents visual and sound information as finite binary values. Increasing resolution, sampling rate, bit depth or frame rate generally increases raw storage and bandwidth requirements.
| Medium | Representation | Key parameters |
|---|---|---|
| Images | Raster pixels or vector drawing instructions | Dimensions and colour depth |
| Audio | Sampled amplitudes mapped to discrete levels | Sampling rate, bit depth and channels |
| Video | Successive frames, often with synchronized audio | Frame dimensions, colour depth and frame rate |
Raster images suit photographs; vector graphics suit scalable icons. A colour depth of bits permits up to pixel values. PNG uses lossless raster compression, JPEG typically uses lossy raster compression, and SVG represents vector graphics.
🧠 Key Concepts
- Raster and vector
- Colour depth
- Audio sampling
- Quantization
- Aliasing
- Frame rate
- Raw media size
- Lossless and lossy
- Inter-frame compression
- Codecs and containers
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Representing Images, Audio and Video
📘 Overview Computers represent images, audio and video as binary data using discrete samples, encoded structures and compression. Resolution, sampling rate, bit depth and frame rate determine how much information is captured and how much storage or bandwidth is required.
🧠 Key Idea Digital media encodes visual or sound information as finite values. Increasing sampling density or precision generally increases raw data size; compression reduces that size through redundancy removal or controlled information loss.
⚔️ Core Details: - Raster images store a grid of pixels with encoded colour values; vector images store geometric shapes and drawing instructions. - Colour depth determines the number of representable pixel values: bits allow up to values. - Audio sampling measures signal amplitude at regular intervals; avoiding aliasing requires
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Part of 🗄️ BS Information Systems — 1st Year
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