This document discusses how images are represented digitally through binary data and pixels. It explains that images are made up of pixels, each with multiple brightness levels determined by the number of bits used. More bits allows for more brightness levels and possible pixel values. The document demonstrates how binary numbers represent a range of values from 0 to 2^n, where n is the number of bits. It provides examples of the number of possible values for 6-bit and 8-bit binary numbers.

1. Information in Images

2. Information in Images We will find out: How images are related to a binary data stream How to calculate the information content of an ‘n’ bit binary number Why logarithmic scales are used to sometimes represent numbers 100011110100010101

3. Pixelated Images Image made of pixels Each pixel has more than just ‘on’ or ‘off’ setting… It has many different levels – this is dependent on the number of bits

4. Bits and Bobs 100011110100010101 This is a bit stream It represents a range of values of ‘zero’ or ‘one’ Each number has a value – 2 n

5. 0 1 0 1 0 1 6 5 4 3 2 1 64 32 16 8 4 2 Bit Stream n 2 n This is a 6-bit number – it has a maximum of 2 6 = 64 possible values The actual value above is 21 – can you see why? What are the number of possible values with 8-bits?

6. 0 0 0 1 0 1 0 1 8 7 6 5 4 3 2 1 256 128 64 32 16 8 4 2 What are the number of possible values with 8-bits? There are 256 values – 0 to 255 or 2 8 Binary numbers are to the base 2 – written log 2