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The term pixel is short for Picture Element - AQA - GCSE Computer Science - Question 7 - 2023 - Paper 2
Question 7
The term pixel is short for Picture Element. Define the term pixel. Figure 1 shows a 5 pixel x 5 pixel image. A minimum colour depth of two bits is needed to store... show full transcript
Worked Solution & Example Answer:The term pixel is short for Picture Element - AQA - GCSE Computer Science - Question 7 - 2023 - Paper 2
Step 1
Step 2
Explain how the image in Figure 1 can be represented as a bitmap.
Answer
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.
Step 3
Calculate the minimum file size, in bits, of this image when represented as a bitmap.
Answer
To calculate the minimum file size of a 10 pixel x 10 pixel image with a color depth of 5:
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The total number of pixels is:
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For 5 different colors, we need a color depth of:
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Therefore, the minimum file size in bits is: