2024-25 - Y8 - Data Representation - Quiz 5

What is a bitmap image made up of?

• Pages
• Parts
• Pixels
• Petabytes

Which of these statements is NOT true about pixels?

• The smallest element of a bitmapped image
• Represents a single colour
• Stores a binary number
• Short for Picture Eliminator

Which of these statements is NOT true about colour depth?

• Represents the number of bits per pixel
• It determines the numbers of colours that each pixel could display
• To be able to use more colours the colour depth needs to be reduced
• Describes the amount of data that is stored in each pixel

A bitmapped image uses a colour depth of 3-bits and this allows for 8 different colours. If the number of different colours that need to be represented increases to 30, what is the minimum new colour depth required?

• 4
• 5
• 6
• 7

Which of these statements is NOT true about image resolution?

• Refers to the clarity of an image
• Describes the size of a bitmapped image in pixels
• Can be improved by reducing the number of pixels
• Can be calculated by multiplying the width in pixels by the height in pixels

A bitmapped image is 10 pixels wide and 15 pixels high. What would be the image resolution in pixels of this image?

• 100 pixels
• 115 pixels
• 105 pixels
• 150 pixels

Which TWO of these would be correct if the resolution of bitmap image was increased from 100 pixels to 1000 pixels?

• File size increases
• File size decreases
• Quality increases
• Quality decreases

Which TWO of these would be correct if the colour depth of a bitmap image was decreased from 8 bits to 3 bits?

• File size increases
• File size decreases
• Quality increases
• Quality decreases

To calculate the file size in bits for a bitmap image, which formula needs to be used? Note: * means multiply / means divide

• File size in bits = height in pixels * width in pixels / colour depth in bits
• File size in bits = height in pixels / width in pixels * colour depth in bits
• File size in bits = height in pixels * width in pixels * colour depth in bits
• File size in bits = height in pixels / width in pixels / colour depth in bits

What is the file size for a bitmap image that is 20 pixels high, 20 pixels wide and uses a 4 bit colour depth?

• 400 bits
• 160 bits
• 1600 bits
• 4000 bits