1.2 Text, Sound and Images Flashcards
What is a character set?
A character set contains all the characters that are in the character set and the binary value that is assigned to each character.
What are the two main types of character sets a computer can use?
ASCII and Unicode
How many bits do ASCII and Unicode use? And how many characters can they each represent?
ASCII Uses 8-bit binary numbers and can represent up to 256 characters
Unicode Uses 16-bit binary numbers and can represent up to approximately 65000
Explain why Unicode requires more bits per character than
ASCII.
I because it can represent many more characters from different languages, To store such a large variety of characters, more bits are required to create enough unique codes for each character, whereas ASCII is limited to basic English characters.
What is sound sampling?
a little piece of sound that is recorded at regular time intervals
What is the sample rate?
the number of samples recorded each second
How can someone improve accuracy when recording sound waves?
To improve accuracy you can increase the sample rate which results in less space between each recorded sample resulting in a clearer recording.
What are sample rates measured in?
Hertz
How are the sample rate and data required for the recording correlated?
If the sample rate increases then the amount of data required for the recording is also increased.
What is a pixel?
a pixel is a very small dot that is displayed with many others to create a image
What is the resolution of a image?
The resolution is the dimensions of the image
What is metadata?
Additional data that I stored with an image that can provide information such as the dimensions of the image and the time and date the image was taken.
What is the color depth?
The color depth is the number of bits that are used to create each color in an image
What are the two things every image has?
Every image has a resolution and a color depth
How is the image resolution and data required for the image correlated?
The file size and quality of the image increases as
the resolution and colour depth increase
