Free Sample: Audio visual technology report paper example for writing essay

Audio visual technology report - Essay Example

When viewed each dot corresponds to an Individual exile on a display and can be assigned a different color and these dots will represent a rectangular Image. The Bitmap format Includes a header which gives information about the file size, number of colors used in image and also a list of pixels with the matching colors. A disadvantage of a bitmap image is they are memory intensive, so the higher the resolution the larger the file will be. Most images nowadays on the web are compressed to JPG, GIF and PANG so they download and open on web pages quicker.

Another disadvantage of bitmap images are when resizing the image the pixels will become peculated producing bad quality images which will become blurry. RUG model and what’s it used for? RUG model Is a common colors used for digital Image representation and there are three mall primary colors which are red, green and blue which are mixed to produce more colors and displayed on a monitor. The mall reason these three colors are the primary color Is because the humans eye Is naturally more sensitive to red, green and blue. The RUG color space is based upon the portion of the electromagnetic spectrum visible to humans (I. E. The continuous range of wavelengths in the approximate range 400-Mann). The human eye has three efferent types of color receptor over which it has limited (and uniform) absorbency for each red, green and blue wavelengths”. (Solomon & Bracken, 2010, p. 1. 41). Some of the input devices which use RUG include color TV’s, Videos cameras, mobile phones, LED displays and video projectors. Color printers use a different color model called CACM.

How RUG is used for images on Computers? Computer systems can be used to represent everything through numbers by using binary numbers which consists of numbers zero and one. In computers the numbers are represented by electronic switches. An open switch represents a zero and a loses switch represents a one. These are known a bits which are stored In the computers memory. Eight bits make a byte of data and most colors are represented zeroes and ones is used to represent a given color. By using the eight zeroes and ones there is 256 combinations to represent different colors.

For example the decimal integer O can be shown in 8-bit binary digits which is in 3 bytes as 00000000, 00000000, and 00000000 while the decimal integer 255 is represented as 1 1 1 1 1 1 1 1, numbers. Hexadecimal has 16 numerals represented by our normal decimal numbers and the first 6 letters of the alphabet (0123456789ABCDEF). For example red, green and blue in hexadecimal is and A bitmap image uses colors with numbers to represent an image. RUG is the most common method used in computers to represent the amount of red, green, and blue primary lights required to mix together to create more colors.

If 8-bit numbers are used then you can have values ranging from O – 255 for each of the RUG primary colors. Black is represented by and white by (255,255,255). The red, green, and blue primary colors would be represented by (255,0,0), (0,255,0), and (0,0,255) respectively. Similarly the cyan, magenta, and yellow secondary would be presented by and AS there 256 combinations for each of the primary colors red, green, blue these are multiplied to see how many different colors can be produced (256 x 256 x 256 = 16. 7 million colors. Fig 1 RUG model showing red, green and blue and decimal values. How to work out the Pixel file Size for image which has width and height 1920 x 1080? 1920 width x 1080 height x bytes = 6. MOB (not compressed) Sample rate and Bit depth Iniquity Theorem The Sample Rate is basically how many samples per second you take of your sound wave. The Iniquity Theorem states that in order for the set bandwidth to be filling seed (or encoded) the sample rate must be at least twice as high as the highest frequency that’s to be recorded. The human ear cannot hear frequencies above kHz.

With this two pieces of information the standard sampling rate has been set at 44. 1 kHz known as 44,100 samples per second. When the sample rate is at 44. 1 kHz the highest frequency that can be sampled is kHz. Another reason to set the sample rate according to the Iniquity Theorem is so that the frequencies are able to be accurately taken and there are no harmonic distortion in the frequencies to be heard by the human hear. To avoid distortion a low-pass filter can be added before the sampling process which will remove any frequencies that come out above the Iniquity Frequency.

As stated above the sample rate is the rate at which samples of analog signal are taken in order to be turned into a Digital form. A sample is a sound bit of a sound waves with rapid changes in the amplitude. Sampling rate changes per specified a numerical value of 1 ‘s and Co’s known as Quantization to convert the voltage levels of an analog signal into binary digits (bits) so that the audio data can be stored in a digital form. Bit Depth is how we describe the amount of numbers signed to each sample during Quantization.

To be stored in a computer all samples must be given a numerical value. These values are the digital expression of the changes of amplitude of the signal were the sample was taken. Binary (bits) are used to determine the range of possible numbers used by the computer to store/read the information. If stored using 8 bits there are 256 possible number combinations. The most common Bit Depth is CD quality which is recorded at 16 bits which has 65,536 are also used. The higher the amount of bits used to store each sample the better the potential ratio of signal to noise.

Dithering and Dynamic range Smith (2002) states that Dithering is a popular technique which can be beneficial to improve the digitization of slow various signals which are being produced. Dithering involves adding white noise to our input signal. It helps by spreading out the little differences in amplitude resolution. The whole point of using dithering is to add random noise so the signal bounces back and forth between successive levels. This will make the signal noisier however the signal smoothen out by averaging this noise digitally once the signal is developed.

Dynamic range is when the ratio of the oftenest sound is described to the loudest sound which can either be thorough an electrical equipment or a musical instrument. The ratio is measured in (DB) decibels. Live music has a dynamic range of 100 to 120 decibels which is very loud. A CD which is 16 bit normally has a maximum dynamic range of DB. 24 bit audio recordings have a maximum dynamic range of DOBB. Fig 2 Chart (Smith 2002) shows original Digital signal and dithered. Bit rate speed Refers to the transfer of the data.

The bit rate is used to show the amount of information which is stored per second and shows the speed when downloading off he internet. Bit rate = (bit depth) x (sampling rate) x (number of channels) 16 X 44100 x 2= 1411200 bit/s equivalent to 1,41 1. 2 kibitz/s How to Calculate the Size off Waffle Size = sample rate x number of channels x (bits per sample/8) x time in seconds. 44100hHz, stereo 16 bit Waffle Lasting 3 minutes Size = (44. 1 * (16/8) 1024 = BOMB A common emitter amplifier is a circuit which is designed to take a small input signal which in normally in millions e. . NV which can then be amplified in the output signal to produce a sound which is more powerful and in volts. Audio amplification an be used in electronic devices such as radio and TV etc. Fig 3 (Blackboard 2013) Common emitter circuit and components. Transistor and resistor Information and connection. The transistor is used in a circuit and has a purpose to act as an amplifier and consists of three pins which are emitter, collector and base. The emitter and a collector are both negative however the base pin is positive.

Resistor 1 and resistor 2 is connected to emitter pin to set the gain and stops the flow of the current traveling into the transistor to stop receiving too much current and burning out. Resistor 3 ND 4 was utilized in the circuit because it allows it to bias the transistor by working a little which allows a small amount of current to flow to ensure that the transistor can amplify positive and negative signals. Capacitor Information It is essential that capacitors are used for the input and output to ensure AC signals are separated from the DC biasing voltage. The capacitor will only pass AC signals and block dc signals.

The capacitor will charge in one route and then discharge going the other route to prevent dc signal. There are connected to the input and output wire to block any DC voltage coming in which can cause distortion. Chip Counter and Binary information The chip counter needs to be attached to the blob board first and the chip counter counts in binary sequence 0-9 and starts over again in 4 bits. For example it can produce 0000, 0001, 0010, 0011 etc. “In the decimal number system each digit of a number represents a power of 10. In a Binary system each digit or bit represents a power of 2”. Ramsey & McCormick 2009, Peg. 203). The chip counter can be addressed four pins of the memory device which was then programmed to produce 8 bits of data. For example the circuit could produce 00000001 or 10000011. The DID convector can be used so that digital signal could be converted to analogue signal so that sounds can be produced. 8 Data lines are needed on the DID convector which are connected to memory device. “This is achieved in simple convectors by using the states of bits to turn current sources on and off making up the required pulse aptitudes by combination of outputs of each of these sources.

The staircase is then resample to reduce the width of the pulses before they are passed through a low pass reconstruction filter whose cut off is half the sample frequency. The effect of the construction filter is to Join up sample points to make a smooth waveform”. (Ramsey & McCormick 2009, Peg. 232). When the data lines are connected the synthesizer can be tested for sound using the mixing desk and speakers and waveforms will be produced on the oscilloscope. File structure of WAVE files. Which includes header, format and also data.

Header Positions Value Description 1-4 RIFF Symbols that the file is a riff file. Characters individually are 1 byte long. 5- 8 File size (integer value) Size of the overall file. 9-12 WAVE The file type is Header so for our purposes the answer will written will be WAVE. Format -3 “FM” Format marker. This is the length of the Format chunk in Binary which is in 8 bits. 8-9 8 bit always equals this number 0100. 10-11 Channel numbers 0100 12-15 Sample rate normally is set to 44100. 16-19 Bytes per second. 0-21 Bytes per sample 22-23 Bits Per sample Data Design of the Patch In this pure data project RUG model which consist of red, green and blue which was used within the pure data project with colors changing different colors depending consisted of various different shapes being used making the piece of work more creative. The draw and line function was used on all the shapes and in order for efferent shapes to appear they were created in the gem head and it was essential to change the gem head number in the patch in order for all the shapes to be seen.

In order for the MIDI keyboard to play the graphic on the screen all the shapes drawn were connected to pitch, velocity and channel. The pitch was used so the higher the note is played the darker the color of the shapes becomes. Velocity was used as if the note was being hit quickly the louder the note would be. The channels on the MIDI keyboard were used on all the shapes which were assigned to separate Hansel and the purpose of using this was to increase the size and decrease the size of the shapes used.

Routing and range was used on the channels to ensure that the size of the shapes aren’t out proportion when displayed on the screen and are within the range of 127 which was set so you are able to use the channel controllers on the MIDI keyboard to control the size of the shape without them messing up causing problems. Fig 4: Pure data patch Logic Gates A logic gate is a fundamental part of building a digital circuit and are the building blocks of how computer work. A lot of the circuits are made using transistors and also diodes.