Data

• Pixel Short for 'picture element' - smallest part of a graphic image
• Binary Number system using only 0 and 1
• Hexadecimal A base-16 number system that uses sixteen distinct symbols 0-9 and A-F to represent numbers from 0 to 15.
• binary values
• MSB Most Significant Bit, the left-most bit in a binary whole number or code
• Two's complement A method in computing of being able to store negative numbers as string of pure binary digits. It works by turning the MSB into a sign bit, where 0 represents a positive number and 1 represents a negative.
• Overflow Error that results when the number of bits is not enough to represent the number.
• Logical Shift Left (<<)Everything moves left by a bit, and the LSB on the right is filled with a zero - multiplication
• logical Shift Right (>>)Everything moves right by a bit, and the MSB on the left is filled with a 0 - division
• Uses of Hexadecimal Defining colours in HTML and MAC addresses
• sequence a basic algorithm: A set of logical steps carried out in order.
• Resolution The number of pixels in an image. Sometimes identified by the width and height of the image as well as the total number of pixels in the image.
• ASCII Industry standard set of characters, limited to 7 bits - 128 unique characters can be represented
• Character set The list of characters recognised by a computer
• Colour depth The number of bits used to encode the colour of each pixel
• Sampling Measurements taken of a sound wave at regular intervals of time
• Fidelity In sound; how accurate the recording is to the original sound.
• High fidelity A very accurate digital recording; often called hi-fi
• Compression Changing the format of a file to decrease the file size
• Lossless compression Compressing a file and not losing any data
• Lossy compression Compressing a file by removing some of the data
• Sample rate The number of samples taken per second, often measured in Kilohertz (kHz)
• Sample interval The distance or time between data points or measurements.
• Bitmap An image composed of pixels with a fixed resolution
• JPG Joint Photographic Experts Group, a file format for images such as photos or images with subtle color changes.
• Arithmetic right shift The ability to divide negative binary numbers; the value (1 or 0) of the MSB is kept
• Bit depth The number of bits used to encode each sound sample during digitisation.
• Amplitude Height of an audio wave: larger amplitude = louder sound
• Data compression Algorithms designed to reduce the number of bits needed to represent a piece of information
• Data capacity The amount of data that can be stored on a secondary storage device or in a computer's memory
• MP3 A standard format for audio files, size can be reduced using lossy compression