Crossing the boundary: analogue universe, digital worlds
Crossing the boundary: analogue universe, digital worlds

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

4.10 Standards again

Whatever compression strategy we adopt – and most real-life approaches use a combination – we again need to have agreement. If I compress a photograph using a certain technique and send it to a friend, her computer will have to be able to decompress it again to display it. So we must have a standard agreement between the parties about how the image has been compressed.

There are many standards for image and film compression. It would be out of place to discuss in detail how they work here – the compression theme is taken up in a later course. All I'll do is note that, among the standards for image compression, two stand out – the JPEG (Joint Photographic Experts Group) and the GIF (Graphics Interchange Format) standards. Both standards reduce the number of bits used to store each pixel. GIF, for example, condenses each pixel from 24 bits to 8, by reducing the set of colours used to a smaller set, called a palette. Image data can sometimes be compressed to one twenty-fifth of the original size.

For video, the dominant standard is MPEG (Moving Picture Experts Group), which is now used in most digital camcorders.

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371