Learn: Data Representation - Images

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What is Data Representation in Images?Computers store images as a collection of pixels (small picture elements). Each pixel is assigned a binary value, which represents its colour.This is important because it allows computers to display images accurately, and the quality of the image depends on factors like resolution and colour depth.

ResolutionResolution refers to the number of pixels in an image, typically measured as width × height (e.g., 1920 × 1080). Higher resolution means more detail, but it also increases file size.Think of resolution like the number of tiles in a mosaic—the more tiles, the clearer the image.

Colour DepthColour depth is the number of bits used to represent the colour of each pixel. For example, 8-bit colour depth allows 256 colours, while 24-bit allows over 16 million colours.Higher colour depth improves image quality but increases file size. Imagine a colouring book with more available colours—it produces more vibrant images but takes longer to print!

MetadataMetadata is data about the image, such as its resolution, colour depth, and file format. This helps software understand how to display the image.For example, metadata allows your phone to know if a picture should be displayed in landscape or portrait orientation.

Image File Size FormulaTo calculate the file size of an image, use this formula:File size = colour depth × image width × image heightThis formula shows how resolution and colour depth both contribute to the total file size.

CompressionCompression reduces the file size of an image. There are two types:Lossy compression: Removes data to reduce size (e.g., JPEG).Lossless compression: Keeps all data but organises it more efficiently (e.g., PNG).

Review Time!Great work! You've learned about pixels, resolution, colour depth, metadata, file size calculations, and compression. Now let's test your understanding!