Data Representation - Images

How many bits per pixel would be required for an image with a palette of 256 possible colours?

• 6

• 7

• 256

• 8

State two factors that affect the file size of a bitmap image.

• Lossy

• Colour depth

• Dimensions of the image in pixels

• Lossless

Which icon image is greater in file size?

A. A 256 colour icon with dimensions of 50 x 50 pixels

B. A 16 colour icon with dimensions of 100 x 100 pixels

Use paper to work this question out.

• A

• B

Additional metadata data is stored alongside the binary colour values for each pixel. Select two examples of metadata

• Name

• Date created

• Author

• Dimensions

• Surname

Jessica has saved following two images as bitmap file types. Select reason for why image B is blurred

• High resolution

• Image has more pixels

• Image has fewer pixels

Image A would also become blurred or pixelated if it was significantly enlarged. Why this would happen?

• There are less pixels

• Pixels are reduced when they are stretched

• Pixels become enlarged when they are stretched

Jessica wishes to email one of the images using a low bandwidth Internet connection. She has chosen to send Image B. Suggest two reasons why?

• Smaller file sizes take less time to upload and send over an Internet connection

• Image B will have a better file size

• Larger file sizes take less time to upload and send over an Internet connection

• Image B will have a smaller file size

Lossy compression.....

• Retains all original image data

• Results in a much smaller file size than lossless

• Removes data permanently

Lossless compression.....

• Retains all original image data

• Results in a much smaller file size than lossy

• Removes data permanently