What do you mean by rate distortion?
Rate–distortion theory is a major branch of information theory which provides the theoretical foundations for lossy data compression; it addresses the problem of determining the minimal number of bits per symbol, as measured by the rate R, that should be communicated over a channel, so that the source (input signal) …
What do you mean by distortion in data compression?
A distortion measure is a mathematical quantity that specifies how close an approximation is its original some distortion criteria. When looking at compressed data, it is natural to think of the distortion in terms of the numerical difference between the original data and the reconstructed data.
What is an RD curve?
The rate distortion (RD) curve is a basic tool for quality evaluation. It looks like a curve line, which shows metric dependence on the bitrate. For the RD curve, any metric can be applied.
Which technique can lower the average distortion?
Negative feedback reduces distortion. All engineers agree on this, but shouting begins immediately afterwards regarding the character and subjective effect of the new distortion.
What is scalar quantization?
In scalar quantization, a scalar value is selected from a finite list of possible values to represent a sample. In vector quantization, a vector is selected from a finite list of possible vectors to represent an input vector of samples.
What is uniform quantizer in data compression?
When the steps are uniform in size, the quantization is called the uniform quantization. Such a system would be wasteful for speech signals; many of the quantizing steps would rarely be used. In a system that uses equally spaced quantization levels, the quantization noise is same for all signal magnitudes.
Why are there two aggregate supply curves?
An increase in aggregate supply due to a decrease in input prices is represented by a shift to the right of the SAS curve. A second factor that causes the aggregate supply curve to shift is economic growth. Positive economic growth results from an increase in productive resources, such as labor and capital.
What is the size of aggregated supply curve?
The aggregate supply curve shows a country’s real GDP. In other words the deliverables it supplies at different price levels. This curve is based on the premise that as the price level increases, producers can get more money for their products, which induces them to produce even more.
What is distortion in communication?
To distort a message means to put it out of shape. A distortion is a sort of linguistic abnormality or anomaly that departs or deviates from the proper meaning of a sign. Intentional distortion alters the perception of a message, thus allowing pre-designed and purposive misrepresentations of a communicated sign.
What is the difference between uniform and non uniform quantization?
The type of quantization in which the quantization levels are uniformly spaced is termed as a Uniform Quantization. The type of quantization in which the quantization levels are unequal and mostly the relation between them is logarithmic, is termed as a Non-uniform Quantization.
What is difference between uniform and non-uniform quantization?
The key difference between uniform and nonuniform quantization is that uniform quantization has equal step sizes while, in nonuniform quantization, the step sizes are not equal.
Which is accurate for uniform quantizer?
For uniform quantization with fixed bit rate, the range directly affects the quantization error. Hence, an accurate estimation of the range leads to a good control of the quantization noise. On the other hand, for nonuniform quantization, the quantization noise depends more on the input values than on the ranges.
Why aggregate supply curve is 45 degree?
The 45-degree line could be viewed as the aggregate supply curve because in the short run, production is perfectly flexible, while price is fixed. Thus, the economy is able to supply whatever the economy demands. Hence, it is as if the aggregate supply curve was the 45 degree line.
What factors cause shifts in aggregate supply?
The aggregate supply curve shifts to the left as the price of key inputs rises, making a combination of lower output, higher unemployment, and higher inflation possible. When an economy experiences stagnant growth and high inflation at the same time it is referred to as stagflation.
Why aggregate supply is upward sloping?
The short-run aggregate supply curve is upward sloping because the quantity supplied increases when the price rises. In the short-run, firms have one fixed factor of production (usually capital ). When the curve shifts outward the output and real GDP increase at a given price.
What are the three types of distortion?
What are the main types of distortion?
- Longitudinal shrinkage.
- Transverse shrinkage.
- Angular distortion.
- Bowing and dishing.
- Buckling.
- Twisting.
What is an example of distortion?
Examples. Distortion is a word that refers to the ways in which things can get confused or changed until they are hard to recognize. A melted crayon, a deflated balloon, a CD or DVD with scratches that no longer plays correctly — these things have all been affected by distortion.
Why do we need non uniform quantization?
a non-uniform quantizer can be designed so that the quantization levels are spaced more closely for smaller amplitudes and spaced more far apart for larger amplitudes. as a result the signal-to-noise ratio can be made constant for both small signals and for large signals.
How non uniform quantization reduces the quantization error?
In non-uniform quantization, the step size is reduced with the reduction in signal level. For weak signals (P < < 1), the step size is small, therefore the quantization noise reduces, to improve the signal to quantization noise ratio for weak signals.
Why do we need non-uniform quantization?