Representing images with binary data
Lesson details
Learning outcome
I can explain how images are represented using binary digits and created using the RGB system.
Key learning points
- Digital pictures are formed out of individual pixels (picture elements).
- The elements in a digital image are arranged in a grid of rows and columns.
- The colour of a pixel can be represented as a mixture of red, green and blue.
Keywords
Pixel - a single element of an image on a computer screen
Bit - a binary digit, the basic unit of data within a computer system that has the value 0 or 1
RGB system - a colour model used to represent and create colours by combining three colours of light: red, green and blue
Intensity - the strength of a colour, shown by the value of each element (red, green or blue)
Common misconception
The number of bits per pixel that represent the colour are always individual specific colours.
When RGB is used to define the colour of a pixel the bits represent different intesities of red, green and blue providing different colour mixes.
Teacher tip
It might be helpful to discuss whether learners have seen pixelated images and why they were used.
Licence
Lesson video
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Prior knowledge starter quiz
4 Questions
Q1.What is binary?
Q2.What can computers store using binary?
Q3.What is a 'bit'?
Q4.What does a pixelated image look like?
Assessment exit quiz
6 Questions
Q1.What does RGB stand for?
Q2.What is the basic unit of data in computing?
Q3.Match the term with its definition:
basic unit of data
the amount of colour from 0 to 255
a single element of an image
Q4.What is the maximum number of colours can be represented by 2 bits per pixel?
Q5.What does the term 'intensity' refer to in digital imaging?
Q6.How many pixels are in an image that has a grid of 5 x 5 pixels?
To help you plan your 9 computing lesson on: Representing images with binary data, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 9 computing lesson on: Representing images with binary data, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 computing lessons from the Data representation: images and sound unit, dive into the full secondary computing curriculum, or learn more about lesson planning.