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Data storage - Coggle Diagram
Data storage
Data types
The computer industry uses the term "MULTIMEDIA" to define information that contains numbers, text, images, audio and video
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Bits (binary digit) : The symbol 0 or 1 is called a bit (binary digit), the smallest unit of data that can be stored in a computer.
Bits patterns a sequence, or a string of bits. A bit patterns with 8 bits is called a byte
Storing numbers
Storing integers
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In sign-and-magnitude representation, the leftmost bit defines the sign of the integer. If it is 0,the integer is positive. If it is 1, the integer is negative
Both positive and negative overflow when storing an integer in sign-and-magnitude representation using a 4-bit memory location.
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Storing Reals
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Real numbers with very large integral parts or very small fractional parts should not be stored in fixed-point representation
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Floating-Point Representation for a Real number: a sign, a shifter and a fixed-point number
Storing Text, Audio(media)
Storing Text
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We can represent each symbol with a bit pattern. In other words, text such as “CATS”, which is made up from four symbols, can be represented as four n-bit patterns, each pattern defining a single symbol.
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Storing Audio
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Sampling means that we select only a finite number of points on the analog signal, measure their values, and record them.
Quantization refers to a process that rounds the value of a sample to the closest integer value. The value measured for each sample is a real number. This means that we can store 40,000 real values for each one second sample
bit depth or number of bits per sample B, the number of samples per second, S, we need to store S × B bits for each second of audio. This product is sometimes referred to as bit rate
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Storing Images,Video
Storing Images
raster graphics
Raster graphics (or bitmap graphics) is to store an analog image such as a photograph. A photograph consists of analog data, similar to audio information. The difference is that the intensity (color) of data varies in space instead of in time.
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Color Depth : The number of bits used to represent a pixel, its color depth
Color
True-Color: encode a pixel is called True- Color, which uses 24 bits to encode a pixel
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disadvantage: : the file size is big and rescaling is troublesome so the image looks ragged when it is enlarged
vector graphics
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Standards for Vector Graphis EPS, WMF, AI, CDR
Softwares: Illustrator, CorelDRAW, Flash
Storing Video
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video is the representation of information that changes in space (single image) and in time (a series of images).