Multimedia (Cambridge (CIE) A Level Computer Science): Exam Questions

A computer system stores text, images and sound.

The colour of each pixel in a bitmapped image is represented by 8 bits.

(i) State the largest number of different colours that can be represented by 8 bits.

(1)

(ii) State one drawback of increasing the number of bits that represents each pixel in the bitmap image.

(1)

(i) Explain how an analogue sound wave is converted into digital data.

(2)

(ii) Describe one method of compressing a sound file using lossy compression.

(2)

The digital camera has a microphone which is used to record the sound for the video.

The user changes the sampling rate that the microphone uses from 44.1kHz to 88.2kHz.

Describe how this change in sampling rate will affect the performance of the video doorbell.

The computer can transmit a video made from bitmap images and vector graphic animations to the VR headset.

(i) Describe how the data for a bitmapped image is encoded.

(3)

(ii) Describe the contents of a vector graphic drawing list.

(2)

A photograph is stored as a bitmap image.

The photograph has a resolution of 4000 pixels wide by 3000 pixels high. The bit depth is 4 bytes.

Calculate an estimate for the file size of the photograph in megabytes.

Show your working.

Identify two elements of a bitmap image that can be changed to reduce its file size.

Draw one line from each vector graphic term to its most appropriate description.

State what is meant by the bit depth of a bitmap image and explain how changing the bit depth affects the image.

Explain the impact of changing the sampling resolution on the accuracy of a sound recording.

A bitmap image has a resolution of 2048 pixels wide and 1024 pixels high.

The image has a bit depth of 10 bits per pixel.

Estimate the file size of the bitmap image in mebibytes. Show your working.

State what is meant by analogue data.

Draw one line from each term to its most appropriate description.

Describe the impact of increasing the image resolution on the quality of a bitmap graphic.

Calculate the file size of a bitmap image using the following information:

• image resolution of 2048 pixels wide and 1024 pixels high

• bit depth of 16 bits.

Give your answer in kibibytes. Show your working.