Question 1: Explain what a pixel is in the context of digital images.

Answer: A pixel is the smallest individual element of a digital image, representing a single point of colour or shade within the image.

Question 2: Describe how the colour white is represented in a 24-bit RGB colour model.

Answer: In a 24-bit RGB colour model, white is represented by setting the red, green, and blue components to their maximum value, which is 255. Therefore, white is (255, 255, 255).

Question 3: What is the main difference between lossy and lossless image compression?

Answer: Lossless compression reduces file size without losing any image data, allowing the original image to be perfectly reconstructed. Lossy compression reduces file size by removing some image data, which can lead to a loss of quality.

Question 4: Complete the truth table for the AND logic gate with inputs A and B:

Answer: A | B | Output ---|---|-------- 0 | 0 | 0 0 | 1 | 0 1 | 0 | 0 1 | 1 | 1

Question 5: Draw a logic circuit that represents the OR gate with two inputs.

Answer: A correct sketch would show two input lines entering an OR gate symbol (a curved shape with two inputs on the left and one output on the right).

Question 6: A digital image uses 8 bits per pixel. How many different colours can this image display?

Answer: With 8 bits per pixel, the image can display 2^8 = 256 different colours.

Question 7: Sketch a simple diagram to illustrate how a pixel's colour might be stored in binary form in an 8-bit grayscale image.

Answer: A sketch should show an 8-bit binary number (e.g., 00101101) labeled as 'Pixel value' to indicate how the intensity of grey is stored in binary.

Question 8: Explain the purpose of colour depth in digital images.

Answer: Colour depth determines the number of bits used for each pixel, which affects the range of colours or shades that can be represented in the image.

Question 9: Describe how transparency (alpha channel) is used in digital images with an example.

Answer: An alpha channel stores transparency information for each pixel, allowing parts of an image to be see-through or semi-transparent, such as in overlay images.

Question 10: Draw a truth table for the XOR logic gate with inputs A and B.

Answer: A | B | Output ---|---|-------- 0 | 0 | 0 0 | 1 | 1 1 | 0 | 1 1 | 1 | 0

Question 11: Sketch a diagram of a simple pixel grid representing a 2x2 image, labeling each pixel with its binary colour value in a grayscale image.

Answer: A 2x2 grid with four squares, each labeled with an 8-bit binary number (e.g., 00000000 for black, 11111111 for white, or other values for shades).