Learn: Data Representation - Images

Welcome!I've reviewed your growth areas and created this lesson to help you strengthen your understanding of Data Representation - Images. Let's explore how computers store and represent images using binary data.

What is Image Representation?Computers store images by breaking them down into tiny units called pixels. Each pixel contains colour information, which is stored as binary data. The quality and size of an image depend on the resolution and colour depth.

PixelsA pixel is the smallest unit of an image. Each pixel represents a single point of colour. When many pixels are combined, they form the complete image seen on a screen.

ResolutionThe resolution of an image refers to the number of pixels it contains, usually described as width × height (e.g., 1920 × 1080). Higher resolution means more pixels, resulting in better image quality but larger file size.

Colour DepthColour depth refers to the number of bits used to represent the colour of each pixel. More bits mean more available colours. For example, 8-bit colour depth allows 256 colours, while 24-bit allows over 16 million colours.

MetadataMetadata is additional information about an image, such as its resolution, colour depth, and file format. Metadata helps software interpret and display the image correctly.

Calculating Image File SizeThe file size of an image can be calculated using the formula: File size = Colour depth × Image width × Image height. This gives the size in bits, which can be converted to bytes, kilobytes, etc.

CompressionCompression reduces the file size of an image. Lossy compression removes some data to make the file smaller, while lossless compression keeps all the original data intact.

Review Time!Great work! You've learned about how images are represented using pixels, resolution, colour depth, metadata, file size calculations, and compression. Let's test your understanding with a few final questions.