Learn: Images as Pixels - Representing Pictures in Binary

Welcome!Brilliant work so far! You've already explored binary data and how computers store text, images, and sound. Now let's build on that and dive into how computers represent images using pixels and binary.

What are Pixels?Images are made of tiny dots called pixels (picture elements). Each pixel stores a single colour. The computer uses binary data to represent the colour of each pixel.Think of pixels like tiles on a mosaic—each one contributes to the overall picture.

Colour DepthColour depth is the number of bits used to represent the colour of a pixel. More bits mean more colours can be stored. For example, 8 bits can represent 256 colours.Higher colour depth improves image quality but increases file size.

ResolutionResolution is the number of pixels in an image, measured as width × height (e.g., 1920 × 1080). More pixels mean finer detail but also larger file sizes.Imagine zooming into a digital image. If it's made of many pixels, the image will look sharp even when enlarged.

MetadataMetadata is information about the image, like its resolution, colour depth, and file type. This helps software understand how to display the image.For example, metadata might state the image is 800 × 600 pixels with 24-bit colour depth.

Calculating Image File SizeTo calculate the file size of an image, use this formula:File size = colour depth × width × heightFor example, an image with resolution 1024 × 768 and 24-bit colour depth would be:1024 × 768 × 24 bits = 18,874,368 bits (divide by 8 for bytes).

Review Time!Fantastic work! You've learned how computers use pixels, colour depth, resolution, and metadata to represent images. Let's test your understanding with a few questions.