Quantization
Quantization refers to the process of approximating the continuous set of values in the image data with a finite (preferably small) set of values. The input to a quantizer is the original data, and the output is always one among a finite number of levels. The quantizer is a function whose set of output values are discrete, and usually finite. Obviously, this is a process of approximation, and a good quantizer is one which represents the original signal with minimum loss or distortion.
A quantizer simply reduces the number of bits needed to store the transformed coefficients by reducing the precision of those values. Since this is a many-to-one mapping, it is a lossy process and is the main source of compression in an encoder. Quantization can be performed on each individual coefficient, which is known as Scalar Quantization (SQ).
There are two types of quantization - Scalar Quantization and Vector Quantization. In scalar quantization, each input symbol is treated separately in producing the output, while in vector quantization the input symbols are clubbed together in groups called vectors, and processed to give the output. This clubbing of data and treating them as a single unit increases the optimality of the vector quantizer, but at the cost of increased computational complexity.
Coefficients that corresponds to smooth parts of data become small. (Indeed, their difference, and therefore their associated wavelet coefficient, will be zero, or very close to it). So we can throw away these coefficients without significantly distorting the image. We can then encode the remaining coefficients and transmit them along with the overall average value.
Discrete Wavelet Transform (DWT):
A discrete wavelet transformation apply on an image consists of four frequency bands as given in figure (4.1). The top- left corner of the transformed image is the LL band of original image, low-frequency coefficients. The bottom-right corner "HH" contains residual diagonal frequencies. The main reason for use DWT, for reduce an image dimensions, and the high-frequencies coefficients are ignored (i.e. not used in this work), this will effects on the image quality, while this process increasing compression ratio.
Figure (4.1): Original Image After Discrete Wavelet Transform Application
JPEG Technique:
JPEG is a lossy image compression method for color or grayscale images. An important feature of JPEG is its use the quality parameter "Quality", allowing the user to adjust the amount of the data lost over a very wide range. In this work we apply this technique on the sub-image LL, and the image quality problem are solved in the (4.
An encoder is a type of circuit that takes an input and then converts that into a bit binary code which can be read by digital systems. The encoder that we will be using is model number HT12E. The benefits for this encoder are that it uses lower power and contains high noise immunity CMOS technology. [5] This
Tanaka, K., Saito, H. A., Fukada, Y., & Moriya, M. (1991). Coding vidual images of objects
In 1864, James Clerk Maxwell revolutionized physics by publishing A Treatise On Electricity And Magnetism (James C. Maxwell, Bio.com), in which his equations described, for the first time, the unified force of electromagnetism (Stewart, Maxwell’s Equations), and how the force would influence objects in the area around it (Dine, Quantum Field Theory). Along with other laws such as Newton’s Law Of Gravitation, it formed the area of physics called classical field theory (Classical Field Theory, Wikipedia). However, over the next century, quantum mechanics were developed, leading to the realization that classical field theory, though thoroughly accurate on a macroscopic scale, simply would not work at a quantum, or subatomic scale, due to the extremely different behaviour of elementary particles. Scientists began developing a new ideas that would describe the behaviour of subatomic particles when subjected to the fundamental forces (QFT, Columbia Electronic Dictionary)(QFT, Britannica School). Einstein’s theory of special relativity, which states that the speed of light is always constant and as a result, both space and time are, in contrary, relative, was combined into this new theory, allowing for accurate descriptions of elementary
...urate coding is following the directions of sort. Knowing what the different term mean such as includes notes, and see also. Instructions that tell you to check fourth and fifth digits are crucial to follow. If I take my time, study, and practice, I believe I will be a very efficient and accurate coder.
When people think of comparison and likeness, they rapidly jump to immediate observations and obvious detections. They fail to perceive the more imperative and subtle attributes. Whether anybody knows it or not, everything that inhabits the world and even the universe is alike in at least one way. All of these substances contain matter. Matter is the physical substance which encompasses everything, from dusty nebulas to the food on one’s dinner plate. It can be described as anything that has mass and takes up space. Within this matter are infinitesimal particles called atoms. So far, they are what scientists believe to be the smallest part of anything and can even be synthesized in labs (Oxlade 7.) The knowledge scientists possess of atoms is huge, in contrast to their microscopic size. In fact, modern day scientists would not have even obtained this knowledge if preceding chemists and physicists did not unveil what was covered. They paved the way to the vast expansion of awareness and allowed the atom to be seen in its true form. However, these impeccable discoveries did not spawn from a single human being, but rather from a chronological timeline of coincidental events.
The filter, an amplifier with an electronic filter referred to as a bandpass filter, is set to only allow a specific range of frequencies to continue on. The filter uses rejection to block any frequencies that do not fall into this range. This is helpful in reducing a lot of noise and giving a clear signal. Harmonic imaging is where the fundamental frequencies are actually filtered out, allowing the harmonic frequencies to pass through (Kremkau, 2011). Coded excitation helps with harmonics by creating shorter and stronger pulses. Detection, or demodulation, is where the echo voltages, which are received as radio frequencies, are converted into amplitude/video form (Miele, 2006). This happens in two parts, rectification and smoothing. During rectification the pulses are cut into ½ wave sections and refigured making them appear all positive. With smoothing, the humps are smoothed out so the pulse appears in video form. Dynamic range is used to compress the intensity ratio into one that can be displayed (Kremkau, 2011). Figure 2 shows the effect of different dynamic range settings on the same image. There is a large difference between the dynamic range that the human eye is able to detect and that of the reflected signals, and for this reason, compression must be performed (Miele,
People are familiar with measuring things in the macroscopic world around them. Someone pulls out a tape measure and determines the length of a table. A state trooper aims his radar gun at a car and knows what direction the car is traveling, as well as how fast. They get the information they want and don't worry whether the measurement itself has changed what they were measuring. After all, what would be the sense in determining that a table is 80 cm long if the very act of measuring it changed its length!
There are a great number of applications for Digital Signal Processing and in order to better understand why DSP has such a large impact on multiple aspects of society, it helps to better understand the wide variety of applications it can be used for. Here we will briefly look into the following applications of Digital Signal Processing and their uses; speech and audio compression, communications, biomedical signal processing and applications in the automobile manufacturing industry. Li Tan [1] goes into detail with each of these applications in his book, Digital Signal Processing, and explains how each are used on a daily basis.
Spectroscopy Spectroscopy is the study of energy levels in atoms or molecules, using absorbed or emitted electromagnetic radiation. There are many categories of spectroscopy eg. Atomic and infrared spectroscopy, which have numerous uses and are essential in the world of science. When investigating spectroscopy four parameters have to be considered; spectral range, spectral bandwidth, spectral sampling and signal-to-noise ratio, as they describe the capability of a spectrometer. In the world of spectroscopy there are many employment and educational opportunities as the interest in spectroscopy and related products is increasing.
Virtualization has a few different meanings based on the use case. Generally speaking in terms of computing, virtualization means to create a virtual version of a device or resource, such as
Quantitative Research is used to quantify the problem by way of generating numerical data or data that can be transformed
Kasthurirangan, B. 2011. Graceful Degradation and Progressive Enhancement. [online] Available at: http://www.graphicmania.net/graceful-degradation-and-progressive-enhancement/ [Accessed: 22 Mar 2014].
The date is April 14, 2035 a young woman is woken up by the silent alarm in her head. She gets up and steps into her shower where the tiles sense her presence and calculate the water to the precise temperature that she likes. The news flashes in her eyes announcing that today is the tenth anniversary of the day quantum computing was invented. She gets dressed and puts on her favorite hat with a smartband embedded in the rim, allowing her access to anything she needs just by thinking it. Her car is waiting with her trip preprogrammed into it. She arrives at the automated airport to see her associate waiting for her. By the look in his eyes she can tell he is doing a quick online search in his mind. Technology is constantly growing and soon this future will be a reality.
QUAN may, to put it simply, be defined as the techniques that involve the data gathering, analysis, interpretation, and reporting of numerical information in sequence order.
The ability to alter images can open creative outlets for photographers and In turn, produce better quality work. Any photog...