1. What is metadata? Give an example.
- Metadata is data that describes other data, it summarizes basic information about data. Genrally it includes the name of the owner of computer also dates of criation and modification of teh data.
example - File name itself
2. What is a model?
- represeation of a photograph in bits.
- process of capturing
- 2 steps : Translating into bits and rendering
3. What's the difference between a raster image and an ASCII representation of a text document?
- raster image - representation based on divisions of pixels
ASCII - collection of 8 bit codes. representing symbols/letters.
4. What are filename extensions? What are they used for?
- three letters after the dot ( end of the file name) it indicates how this file should be interpreted
5. What is lossless representation? What is lossy representation? What are the trade-offs in using each representation?
- lossless representation - allows exacly the same image to be rendered (no data lost)
- lossy representation - allows an approximation of same image to be rendered (part of a data lost)
-lossless representation is good because data is not lost, however size of the file is larger than one of a lossy representation and it takes more time it to be interpreted .
- quality in lossy representation is lower because part of the data is lost
6. What is steganography and what is it used for?
- the art of sending secret messages in imperceptible ways.
- used to send a secret code with data and only particular people can read this message.
7. What would you have to do to delete a document from your computer so that it could not possibly be read by anyone else?
- You should delete this file from the trash, ( yous should empty the trash)
- zeroing