loading, etc.)? Explain that a binary code is used to represent the colour of a pixel. The number of bits used to store each pixel’s colour is known as the ‘colour depth’. The greater the colour depth, the more colours can be represented. Explain that all colours are combinations of red, green and blue. Give pupils the opportunity to see this for themselves by experimenting with the RGB Explorer: . Explain that any colour can be encoded as a set of three numbers. ‘True colour’ allocates 1 byte for red, 1 byte for green and 1 byte for blue (24-bit colour depth). Point out that a computer needs to know the image size in pixels and the colour depth in order to be able to read the binary data correctly and reproduce the image. This additional information is called ‘metadata’. Explain that it is impossible to produce an exact copy of an image as a bitmap. Bitmaps are representations of the original and some loss of detail is inevitable. Even if a pixel is very small, the colour is unlikely to be uniform across the whole pixel. The binary code represents an average for the whole pixel. The smaller the size of the pixels used, the closer the digital representation is to the original. Ask students to complete Activity 1.1.2. Homework: Ask students to complete Activity 1.1.3. 2 Dictionaries Ask students to explain what a dictionary does (as in a physical book type Week 1 2.3.2 dictionary!). Lesson 2 (extension) activities
loading, etc.)? Explain that a binary code is used to represent the colour of a pixel. The number of bits used to store each pixel’s colour is known as the ‘colour depth’. The greater the colour depth, the more colours can be represented. Explain that all colours are combinations of red, green and blue. Give pupils the opportunity to see this for themselves by experimenting with the RGB Explorer: . Explain that any colour can be encoded as a set of three numbers. ‘True colour’ allocates 1 byte for red, 1 byte for green and 1 byte for blue (24-bit colour depth). Point out that a computer needs to know the image size in pixels and the colour depth in order to be able to read the binary data correctly and reproduce the image. This additional information is called ‘metadata’. Explain that it is impossible to produce an exact copy of an image as a bitmap. Bitmaps are representations of the original and some loss of detail is inevitable. Even if a pixel is very small, the colour is unlikely to be uniform across the whole pixel. The binary code represents an average for the whole pixel. The smaller the size of the pixels used, the closer the digital representation is to the original. Ask students to complete Activity 1.1.2. Homework: Ask students to complete Activity 1.1.3. 2 2.3.2 (extension) Dictionaries Ask students to explain what a dictionary does (as in a physical book type dictionary!). Week 1 Lesson 2 activities
GCSE16_COMPSCI_Y10Summer_Term_SOW.docx