1.2. Multimedia Graphics
A subsection of Computer Science, 9618, through 1. Information representation
Listing 3 of 3 questions
Draw one line from each image representation term to its correct definition. Term Definition Pixel Bit depth Image resolution File header The number of pixels wide by the number of pixels high The smallest identifiable component of an image Stores data about the image file, e.g. file format, number of bits per pixel, file size The number of bits used to represent each colour The following section of a bitmap image is 10 pixels wide and 5 pixels high. In this example, each colour is represented by a letter, e.g. B is blue. B B B B B B B B B B Y Y P Y Y Y P Y Y Y R R M R P K T T R R B O P Y Y Y P G P P R O R P P P R R R R The complete image can have up to 256 colours. Identify the smallest number of bits that can be used to represent each colour in the complete bitmap image. Calculate an estimate for the file size of the section of the bitmap image shown, giving your answer in bytes. Use your answer from part . Show your working. Working Answer bytes Describe how changing the colour depth of an image affects its file size. The first row of pixels in the image from part is shown: B B B B B B B B B B Explain how this row of pixels can be compressed using lossless compression.
9618_s22_qp_12
THEORY
2022
Paper 1, Variant 2
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Images are being created to advertise holidays. Some of the images are bitmap images and some are vector graphics. Complete the table by defining the image terms. Term Definition Drawing list Pixel Colour depth The bitmap images are photographs of the holiday locations. Colour depth and image resolution are both included in the file header of a bitmap image. Identify two other items that could be included in the file header of each photograph. One of the photographs has a bit depth of 8 bytes and an image resolution of 1500 pixels wide and 3000 pixels high. Calculate the file size of the photograph in megabytes. Show your working. Working File size MB The photographs are compressed before they are uploaded to a web server. Customers download the photographs from this web server. Explain the reasons why compressing the photographs will benefit the customers. An image can be compressed using run‑length encoding (RLE). Explain the reasons why RLE may not reduce the file size of a bitmap image. Give one example in your answer.
9618_s23_qp_11
THEORY
2023
Paper 1, Variant 1
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Riya has created the following logo as a vector graphic. R Complete the table by writing a description of each vector graphic term and give an example for this logo. Term Description Example from logo Property Drawing list Riya takes a photograph using a digital camera. The photograph is stored as a bitmap image. Describe two differences between a vector graphic and a bitmap image. Riya needs to email the photograph. She compresses the photograph before sending it using an email. Describe two lossy methods that Riya can use to compress the image. Method 1 Method 2
9618_w21_qp_12
THEORY
2021
Paper 1, Variant 2
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Questions Discovered
3