The term pixel is short for Picture Element - AQA - GCSE Computer Science - Question 7 - 2023 - Paper 2

The image in Figure 1 can be represented as a bitmap by storing the pixels in a grid format. Each pixel in the image can be represented using binary values based on a 2-bit color depth. With 2 bits, there are 4 possible combinations of color that can be assigned:

• 00 for black
• 01 for white
• 10 for grey
• 11 for light grey

Thus, each pixel is associated with a unique 2-bit binary code. The 5x5 image would be stored as an array of these binary values, where each pixel maps to a specific color representing its position in the image.

To calculate the minimum file size of a 10 pixel x 10 pixel image with a color depth of 5:

1. The total number of pixels is:

   $10 \times 10 = 100 \text{ pixels}$

2. For 5 different colors, we need a color depth of:

   $\lceil \log_2(5) \rceil = 3 \text{ bits}$

3. Therefore, the minimum file size in bits is:

   $100 \text{ pixels} \times 3 \text{ bits/pixel} = 300 \text{ bits}$