Topic 1f
Storage of things beyond numbers
Learning Outcomes
By the end of this topic students should be able to:
- Explain how a photo is encoded in [24 | 32] bit format.
- Calculate the size in memory of an uncompressed photo in [24|32]-bit format.
- Explain how a sound file is encoded.
- Calculate the size in memory of an uncompressed sound file.
- Explain how a text file is encoded in [ASCII | UNICODE] format.
- Calculate the size in memory of an uncompressed text file in [ASCII | UNICODE] format.
Learning Materials
- Readings
- Section 1.4 - pp 43-50
- Videos
- Dr. Schafer talks about moving beyond bits as numbers
- Dr. Schafer explains how the computer stores text
- Dr. Schafer explains how the computer stores images
- Dr. Schafer explains how the computer stores sound
- Dr. Schafer explains how do we calculate the approximate size of a file?
- Dr. Diesburg explains why terms like KB, MB, and GB have "double meanings" (ignore the reference to a study guide question)
- Activity
- In order to explore the different encodings/values of one byte you can use the following scratch program.
Checking for Understanding
Answer the following questions from your textbook. The answers to all Q&E questions are in the back of your book in Appendix F.
- p49, #1
- p50, #2
- p50, #3
- p50, #9
- p50, #10
Consider the following questions that ask you to determine the size of the file storing different media.
- I am going camping and I send my spouse a text message saying "Made it to the campground safetly. It's beautiful!!!" Assuming that the message is encoded in Unicode format (16-bits), how many bytes of data are needed to store this message?
- I took a 2400x1600 pixel photo of my campsite and sent it to my spouse. Assuming that the image was stored in 24 bit color, and uncompressed, approximately how many kilobytes of storage are needed to store this photo?
- In the middle of the night I hear a strange noise outside of my tent. I record this sound using 16-bit mono with a samplng rate of 44100. If I send 15 seconds of this sound to my spouse, how many kilobytes of storage are needed to store this uncompressed sound file?
Answers & Guidance
The answers to the CFU questions above are provided in the back of the book. The following videos explain how we would arrive at some of those answers.