Bitmap Image Simulator

Every photo, icon, emoji and piece of pixel art you see on a computer has to be stored digitally. But have you ever wondered how a computer can save an image using nothing more than 1s and 0s?

One of the most common ways of storing images is as a bitmap. A bitmap image is made up of thousands (or even millions) of tiny coloured squares called pixels. Each pixel stores a numerical value that represents its colour, and together these pixels combine to create the picture you see on the screen.

The quality of a bitmap image depends on two important factors. Resolution is the number of pixels used to create the image. A higher resolution contains more pixels, allowing the picture to show finer detail, but it also increases the amount of data that must be stored. Colour depth determines how many bits are used to store the colour of each pixel. A greater colour depth allows many more colours to be represented, producing smoother and more realistic images, but again increases the file size.

Bitmap images also contain metadata. This is information about the image rather than the picture itself. Metadata can include the image width and height, the colour depth, the file format and, depending on the file type, additional information such as the date the image was created, the device used to capture it or even the author’s details.

Our interactive Bitmap Image Storage Simulator lets you explore these ideas for yourself. Choose from a selection of classic pixel-art sprites or create your own image by colouring individual pixels. Experiment with different resolutions and colour depths, watch the binary data that is generated for every pixel, investigate how the file size changes, and discover the metadata that must be stored alongside the image.