Multimedia Systems free essay sample

Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion. Raw video can be regarded as being a series of single images. There are typically 25, 30 or 50 frames per second. There are two types of video recording systems/formats. Also, the term video (video meaning I see, from the Latin verb videre) commonly refers to several storage formats for moving pictures. These are Analog Video and Digital Video. The world we sense is full of analog signal; electrical sensors such as transducers, thermocouples, microphones convert the medium they sense into electrical signals. These are usually continuous and still analog. These analog signals must be converted or digitised into discrete digital signals that computer can readily deal with. Special hardware devices called Analog-to-Digital converters perform this task. For playback Digital-to-Analog must perform a converse operation. Analog Video Analog Video is usually captured by a video camera and then digitised. We will write a custom essay sample on Multimedia Systems or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Digital Video Digital video is a type of video recording system that works by using a digital rather than an analog video signal. Digital video comprises a series of orthogonal bitmap digital images displayed in rapid succession at a constant rate. In the context of video these images are called frames. We measure the rate at which frames are displayed in frames per second (FPS). Since every frame is an orthogonal bitmap digital image it comprises a raster of pixels. If it has a width of W pixels and a height of H pixels we say that the frame size is WxH. Pixels have only one property, their color. The second half contains only the even-numbered lines. Those halves are referred to individually as fields. Two consecutive fields compose a full frame. If an interlaced video has a frame rate of 15 frames per second the field rate is 30 fields per second. All the properties and formulas discussed here apply equally to interlaced video but one should be careful not to confuse the fields per second with the frames per second. Properties of compressed video The above are accurate for uncompressed video. Because of the relatively high bit rate of uncompressed video, video compression is extensively used. In the case of compressed video each frame requires a small percentage of the original bits. Assuming a compression algorithm that shrinks the input data by a factor of CF, the bit rate and video size would equal to: BR = W * H * CD * FPS / CF VS = BR * T / CF Please note that it is not necessary that all frames are equally compressed by a factor of CF. In practice they are not so CF is the average factor of compression for all the frames taken together. The above equation for the bit rate can be rewritten by combining the compression factor and the color depth like this: BR = W * H * (CD / CF) * FPS The value (CD / CF) represents the average bits per pixel (BPP). As an example, if we have a color depth of 12bits/pixel and an algorithm that compresses at 40x, then BPP equals 0. 3 (12/40). So in the case of compressed video the formula for bit rate is: BR = W * H * BPP * FPS In fact the same formula is valid for uncompressed video because in that case one can assume that the compression factor is 1 and that the average bits per pixel equal the color depth. Bit rate and BPP As is obvious by its definition bit rate is a measure of the rate of information content of the digital video stream. In the case of uncompressed video, bit rate corresponds directly to the quality of the video (remember that bit rate is proportional to every property that affects the video quality). Bit rate is an important property when transmitting video because the transmission link must be capable of supporting that bit rate. Bit rate is also important when dealing with the storage of video because, as shown above, the video size is proportional to the bit rate and the duration. Bit rate of uncompressed video is too high for most practical applications. Video compression is used to greatly reduce the bit rate. BPP is a measure of the efficiency of compression. A true-color video with no compression at all may have a BPP of 24 bits/pixel. Chroma subsampling can reduce the BPP to 16 or 12 bits/pixel. Applying jpeg compression on every frame can reduce the BPP to 8 or even 1 bits/pixel. Applying video compression algorithms like MPEG1, MPEG2 or MPEG4 allows for fractional BPP values. Constant bit rate versus variable bit rate As noted above BPP represents the average bits per pixel. There are compression algorithms that keep the BPP almost constant throughout the entire duration of the video. In this case we also get video output with a constant bit rate (CBR). This CBR video is suitable for real-time, non-buffered, fixed bandwidth video streaming (e. g. in videoconferencing). Noting that not all frames can be compressed at the same level because quality is more severely impacted for scenes of high complexity some algorithms try to constantly adjust the BPP. They keep it high while compressing complex scenes and low for less demanding scenes. This way one gets the best quality at the smallest average bit rate (and the smallest file size accordingly). Of course when using this method the bit rate is variable because it tracks the variations of the BPP. Video can be recorded and transmitted in various physical media: in magnetic tape when recorded as PAL or NTSC or SECAM electric signals by video cameras or in MPEG-4 (Moving Pictures Expert Group-4 format) or DV (Digital Video) digital media, when recorded by digital cameras. PAL, short for Phase Alternate Line, is an analogue television encoding system used in broadcast television systems in large parts of the world such as Europe, Asia, Australia, parts of Africa (Kenya etc) etc. ). NTSC, named for the National Television System Committee, is the analog television system used in most of North America, most countries in South America, Burma, South Korea, Taiwan, Japan, Philippines, and some Pacific island nations and territories. SECAM (Sequentiel couleur a memoire, French for Sequential Color with Memory), is an analog color television system first used in France, Russia, parts of Africa etc. It is, historically, the first European color television standard. There is also 3D-video, digital video in three dimensions apart from 2D-video. Characteristics of video streams Number of frames per second Frame rate, the number of still pictures per unit of time of video, ranges from six or eight frames per second (frame/s) for old mechanical cameras to 120 or more frames per second for new professional cameras. PAL and SECAM standards specify 25 frames/s, while NTSC specifies 29. 97 frame/s. Film is shot at the slower frame rate of 24photograms/s, which complicates slightly the process of transferring a cinematic motion picture to video. The minimum frame rate to achieve the illusion of a moving image is about fifteen frames per second. Interlacing Video can be Interlaced (Interlace is a technique of improving the picture quality of a video signal without consuming extra bandwidth. Interlaced video was designed for display on CRT televisions. ) or Progressive(Progressive or non-interlaced scanning is a method for displaying, storing or transmitting moving images in which all the lines of each frame are drawn in sequence. ). Interlacing was invented as a way to achieve good visual quality within the limitations of a narrow bandwidth. The horizontal scan lines of each interlaced frame are numbered consecutively and partitioned into two fields: the odd field (upper field) consisting of the odd-numbered lines and the even field (lower field) consisting of the even-numbered lines. NTSC, PAL and SECAM are interlaced formats. Abbreviated video resolution specifications often include an i to indicate interlacing. For example, PAL video format is often specified as 576i50, where 576 indicates the vertical line resolution, i indicate interlacing, and 50 indicate 50 fields (half-frames) per second. In progressive scan systems, each refresh period updates all of the scan lines. The result is a higher spatial resolution and a lack of various artifacts that can make parts of a stationary picture appear to be moving or flashing. A procedure known as deinterlacing can be used for converting an interlaced stream, such as analog, DVD, or satellite, to be processed by progressive scan devices, such as TFT (Thin Fluorescent Tube) TV-sets, projectors, and plasma panels. Deinterlacing cannot, however, produce a video quality that is equivalent to true progressive scan source material. Display resolution The size of a video image is measured in pixels for digital video, or horizontal scan lines and vertical lines of resolution for analog video. In the digital domain (e. g. DVD) standard-definition television (SDTV) is specified as 720/704/640? 480i60 for NTSC and 768/720? 576i50 for PAL or SECAM resolution. However in the analog domain, the number of visible scanlines remains constant (486 NTSC/576 PAL) while the horizontal measurement varies with the quality of the signal: approximately 320 pixels per scanline for VCR quality, 400 pixels for TV broadcasts, and 720 pixels for DVD sources. Aspect ratio is preserved because of non-square pixels. New high-definition televisions (HDTV) are capable of resolutions up to 1920? 1080p60, i. e. 1920 pixels per scan line by 1080 scan lines, progressive, at 60 frames per second. Video resolution for 3D-video is measured in voxels (volume picture element, representing a value in three dimensional spaces). For example 512? 512? 512 voxels resolution, now used for simple 3D-video, can be displayed even on some PDAs. Aspect ratio Aspect ratio describes the dimensions of video screens and video picture elements. All popular video formats are rectilinear, and so can be described by a ratio between width and height. The screen aspect ratio of a traditional television screen is 4:3, or about 1. 33:1. High definition televisions use an aspect ratio of 16:9, or about 1. 78:1. The aspect ratio of a full 35Â  mm film frame with soundtrack (also known as the Academy ratio) is 1. 375:1. Ratios where the height is taller than the width are uncommon in general everyday use, but do have application in computer systems where the screen may be better suited for a vertical layout. The most common tall aspect ratio of 3:4 is referred to as portrait mode and is created by physically rotating the display device 90 degrees from the normal position. Other tall aspect ratios such as 9:16 are technically possible but rarely used. Pixels on computer monitors are usually square, but pixels used in digital video often have non-square aspect ratios, such as those used in the PAL and NTSC variants of the CCIR (Consultative Committee on International Radio) 601 digital video standards, and the corresponding anamorphic widescreen formats. Therefore, an NTSC DV image which is 720 pixels by 480 pixels is displayed with the aspect ratio of 4:3 (which is the traditional television standard) if the pixels are thin and displayed with the aspect ratio of 16:9 (which is the anamorphic widescreen format) if the pixels are fat. EDITING VIDEO Editing videos typically involves: removing frames, inserting frames, mixing audio with video, giving special effects on video, adding transitions between two clips, superimposing clips and adjusting transparency, applying filters to the clips, and adjusting volume of audio. We can also fade-in and fade-out the audio in various frames. In order to edit videos, it is helpful to understand the concept of timecode. Timecode, a unit of measurement, can be used as an address of a frame, and it can also be used as a unit to measure the duration of a video clip. The timecode used by SMPTE (Society of Motion Picture and Television Engineers) has become a standard and is in the form Hrs: mins: secs: frames. For example, a clip with duration of 00:02:31:15 plays for 2 Minutes, 31 seconds, and 15 frames. At the rate of 30 frames per second (fps), 15 frames will take half a second (0. seconds) to play. This clip will, therefore, play for 2 minutes and 31. 5 seconds. Thus, a fraction of a second is measured in frames, and to know the time with millisecond accuracy, we need to know the fps of the clip. The same code can be used to address a particular frame. For example, 00:1:30:12 is the address of the 12th frame that comes after 1 minute and 30 seconds of playing a clip. There are many software packages which support such editing. Some that are well known among these are Adobe Premiere, Adobe After Effects, Strata Avid Video, Asymmetric M Digital Video.

Essay Samples - Great Things to Know About Essay Samples

Essay Samples - Great Things to Know About Essay SamplesThere are thousands of als essay samples available on the internet. Some are easy to use and others are difficult to use, but there is one that will provide you with a total solution to your writing problems and get you writing for the first time in your life.Essays are very popular as they allow students to learn how to write a good writing style, which would mean that they can put it into practice while applying for jobs and even the SAT or ACT exams. There are many types of essays that you could do including conversational essays, creative essays, academic essays, thesis essays, etc. Each essay is chosen based on the theme and the mood that you want to present in your essay. You need to find an essay sample that can help you write for free.There are hundreds of essay samples available online. In fact, you can take a look at them and choose the best of them. For free, you can start reading on the Internet. But, don't just read through them as this will make your day more difficult.You must try out as many sample essays as possible. Try using one sample and if it doesn't work for you, move on to another one. At least three samples should be enough for you to use as a guide. If you want to get something out of your research, you have to write many essays. This way, you will learn how to create your own theme and give meaning to what you are trying to say.Try to choose the samples which would let you know that you can have fun while writing. Most of the free samples are meant to be humorous. Make sure that your sample essay is not just for fun. You have to put something into your essay that is interesting and informative. After all, the purpose of the essay is to explain why the person, which you are writing about, is more than your own person. With this, you will be able to express yourself better.It's also important to understand that there are only two things that matter when you are writing an essay. It is the content and the spelling. There is no other factor, so you have to make sure that you choose the sample which is filled with good information. This is why, you should always check out sample essays which are made by well-known people or colleges.But, if you are too busy to write an essay on your own, you can always hire someone to do it for you. But, it is important that you know that even the best essay writers can become lazy at times. The best thing that you can do is to find out the best essay samples and practice writing from them.

morals of gm foods essays

morals of gm foods essays In this essay I intend to explore the ethical implications of developing genetically modified plants and analyse if the advantages out-weigh the disadvantages. However before I start to discuss the ethical implications of this type of work it is first necessary to clarify exactly what is meant by ethics and genetically modified foods. Ethics are, The study of the general nature of morals and of the specific moral choices to be made by a person; or the rules or standards governing the conduct of a person or the members of a profession: medical ethics. (dictionary.com). In simple terms ethics are the moral code by which we live our lives. They tell us what is right and what is wrong and form our moral conscience. Genetically modified foods are foods where, Desirable genes can be transferred from an organism to a crop plant. (Inge, Rowland and Baker, 2000). This can lead to plants being resistant to viruses and in the case of the corn plant, making it resistant to drought. These are the evident advantages of genetically modified plants but there are disadvantages such as plants being modified so that they become resistant to herbicides and pesticides. If these plants cross-pollinate with other plants then this resistance could spread making plants resistant to all kinds of pathogens. So what are the implications of genetically modified plants? The main concern of many people is the safety of genetically modified plants. This concern arises from the implantation of animals genes into plants and from possible allergic reactions caused by implanting, for example, the genes from a Brazil nut into another product. This did actually happen with the development of a soybean which included a Brazil nut protein however the research was immediately stopped when an allergen problem was detected and the plant was never grown outside of a greenhouse. (Marchant ...

American study final paper Assignment Example | Topics and Well Written Essays - 1500 words

American study final paper - Assignment Example His essay is a detailed analysis of the many examples of advertisements to support this claim. In this essay, the main aim is to show how these different facets of the American culture influence the nature of advertisements. America is considered the most egalitarian society of past and present age. In fact, it is the world’s largest democracy and, therefore, advocates for social equality of its citizens, a populist view. This is one of the two faces of the American dream, the other being an elitist view. This view of the American dream is widely exploited by manufacturers as a way of manipulating consumers to buy their products (Solomon, 543). The status of Americans’ fears, hopes, beliefs, and even desires provide a necessary opportunity for advertisers to make their advertisements appealing to the American people. The desire of the people to feel accepted in society is particularly exploited in such a way that consumers will want to identify with the product to ‘qualify’ as due citizens of the country. These advertisements are specially designed to create a symbolic association between the product and what the target consumers most covet. Manufacturers are, therefore, quick to point out that their products are made, or designed on American soil. One aspect of the American dream is that it encourages the desire to belong and feel part of the country’s culture. This aspect has been the subject of many advertisements that transform economic products into signs of belonging. The incorporation of such common icons of American culture as country music, farmyards and family picnics in an advert makes it more appealing to a broader audience. For instance, a Jack Daniel’s advertisement emphasizes the egalitarian and down-home nature of its product. The feeling of belonging to that culture can influence a buyer

Ergonomics Research Paper Example | Topics and Well Written Essays - 1250 words

Ergonomics - Research Paper Example The overall purpose of such an extensive level of integration with different subjects has to do with the fact that ergonomics is specifically interested in understanding â€Å"human factors† with regards to the function of equipment, the design thereof, and facilitating cognitive abilities in the user. Rather than allowing the name itself, ergonomics, to serve as a stumbling block with regards to an understanding for what the specific realm of analysis is intended upon expecting, it should be understood that ergonomics in and of itself is effectively defined as â€Å"human factors†. As such, these human factors, engaged a level of importance with respect to the design, implementation, and use of material that facilitates the workflow or comfort of an individual. Such a broad level of focus invariably lends this particular field to incorporate a great many factors and engage with the previously denoted fields of study in a variety of different ways. However, even though the field of ergonomics is broad, the information that it engages with is utilized in something of singular manner; to make the experience of the human being more efficient, productive, and/or comfortable. With respect to the way in which ergonomics affects workers, this can be seen with regards to a host of different issues. For instance, the most obvious integration of ergonomics is with regards the way in which certain functions are performed. Rather than merely maximizing efficiency and endangering the worker and/or the equipment in question, ergonomics as a means of utilizing information from relevant medical spheres, up to and including physical therapy as a means of understanding the movements of the human body and which of these are most likely to reduce the level of injury and maximize the health and safety for the individual worker (Larson & Wick 5097). Moreover, the implementation of procedures and equipment that helps to foster a greater focus upon ergonomics directly im pacts the workers as it is able to maximize the level of safety and productivity without having any negative consequences other than the costs of implementation. Evidence of this can of course be seen with regards to the way in which recent scholarship has proven that ergonomics has a direct level of impact with regards to the way in which an office employee maintains posture, avoids injury to the hands and wrists, and has the monitor and keyboard positioned in a favorable manner so that workflow can be maximized and the risk of any potential future harm to the health and safety of the worker can be minimized. But however, even though the information that is thus far been provided is useful with regards to understanding the field of ergonomics and realizing what complement factors helped define it, a secondary issue that must be considered is with regards to the way that hazard recognition and measurement techniques are incorporated as a means of affecting a positive change. Ultimat ely, hazard recognition is the first piece of this puzzle (Erdinc & Yeow 953). Within any field of employment, there are particular hazards that the employee faces on a daily basis. As such, realizing, denoting, and seeking to mitigate these, is a fundamental goal that any organization/firm/company that seeks to engage with ergonomics and improve the overall quality of life and efficiency of workflow for their employees must consider. But naturally, once these hazards have been recognized and

Public Policy Coursework Example | Topics and Well Written Essays - 250 words

Public Policy - Coursework Example Understanding public policy involves a series of individual values towards the realization of a greater goal. Therefore, unlike Science, public policy is an Art. It is, therefore, prudent for policymakers to adopt measures that put the interests of the entire society at heart. â€Å"The basic element of understanding public policy for a better society is communication† (McConnell, 2010 p.89). Policy maker ought to adopt a legal approach towards communicating with the members of the society in an attempt to enhance understanding of public policy. If policymakers created channels for communication, the policies implemented would be favorable to all and ensure that all the relevant factors considered. Policymakers ought to evaluate the effectiveness of policies implemented in terms of their effectiveness towards improving the society (McConnell, 2010). They should install internal control measures to ensure that the policies implemented achieve the objectives. In addition, policies are similar to projects; every project has a lifespan. The internal controls may include evaluations, audits, and reviews. A policy may not achieve its purpose if it is implemented then ignored. Just as an automobile requires servicing, public policies are reviewed to assess whether they achieve the intended purpose. Policymakers are entrusted with public resources, and ought to uphold the code of ethical conduct. They can perfect their craft for the betterment of society if they perform their roles in a manner that upholds and respects moral values and public office respectively (McConnell,

Are Criminals Born or Made? Essay -- Psychology, Micro-Criminological

As the act of criminality is a global phenomenon, there must therefore be some explanation as to why this is; some schools of thought strive to explicate this by means of genetics, whilst others take a more socially influenced approach. Although at the time, the micro-criminological theories of Lombroso and Sheldon may have appeared credible, modern research has attempted to refute such notions. In an epidemiological context, the act of crime is seen by some as a positive contribution to society, as noted by Durkheim (Kirby et al, 2000), although too much will lead to social instability, or anomie. In contrariety to Durkheim's beliefs, a Marxist perspective would consider the mere notion of capitalism as criminal; thus deeming the vast majority of global society to be in a constant state of anomie. However, there is still much dispute as to whether people are born, or made into criminals. This essay will discuss the arguments within this debate. To be ‘born’ criminal ind icates a genetic heredity whereas if one is ‘made’; the environmental influences are the significant factor in creation of criminal behaviour. Despite much controversy surrounding the notion of inherited criminal tendencies, there is much evidence to support such theories. Although Lombroso may have employed his theoretic atavisms in an attempt to provide a biologically deterministic method of reducing or preventing crime, they have ultimately lead to an abandonment of gravitas concerning such a notion. However, as myopic as Lombroso's theories of criminality being a hereditary trait appears (Mannheim, 1965) research has shown shared physical characteristics to be commonplace in explicating the argument of genetic criminal behaviour. Although Lombroso presented... ...e fact it does not claim people will be born destined to commit criminal offences, but rather suggests an inherent predisposition towards such behaviours, which can be influenced by societal factors. In furthering a genetically predisposed and socially-influenced explanation, there is an abundance of considerations when explicating criminal behaviour; for example, a non aggressive, psychologically sound individual may be influenced by peer pressure into recreational drug usage, as â€Å"Psychoactive drug abuse commonly results from a combination of low self-esteem, peer pressure, inadequate coping skills, and curiosity.† (Lippincott Williams & Wilkins, 2005) therefore suggesting that light recreational drug abuse can accrue to a dependence due to a multitude of social influences, which invariably leads to further crime in order to financially support an addiction.