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35 Cards in this Set
- Front
- Back
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Pixels |
Small points of colored light that are arranged in a grid used for digital display. Each point is formed from a combination of 3 colored lights - red, green and blue or RGB |
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RGB |
A combination of 3 colored lights that each pixel is made from |
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Intensities |
The way all colors can be viewed on an RGB digital display. Black = all lights off Red = only red lights on White = all lights all the way up |
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Digital Color vs. Mixing Paint |
Digital color shines light directly towards our eyes whereas mixing paint changes how light is reflected from the object When light is reflected, some of the light is absorbed into the object and the light that is reflected combines to be the color that we see. So mixing yellow and blue paint equals green light. With digital color we are not focused on changing what light is absorbed, we are directly sending light away from the digital display |
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LCD display |
Pixels are combined to make images on this. Also known as an active matrix display |
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Pixels, Bytes, and RGB |
For each pixel there is one byte devoted to red, green, and blue. The intensities of those colors are governed by how the bits are arranged in the byte. The smallest intensity is stored as 0000 0000 The largest intensity is stored as 1111 1111 |
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Bits and RGB |
Each bit contributes half as much power as the bit to its left when increasing the intensity of any single color. |
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Black as bits |
The combination of RGB light at no intensity 0000 0000 0000 0000 0000 0000 Note each byte (8 bits) controls Red Green or Blue |
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White as bits |
The combination of RGB light at full intensity 1111 1111 1111 1111 1111 1111 Note each byte (8bits) controls Red Green and Blue |
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Lightening or Darkening pixels |
To lighten or darken a pixel we can add or subtract binary digits to the pixel's RGB representation one 3 byte sequence plus another 3 byte sequence equals a new 3 byte sequence and therefore a different color |
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Decimal Ranges in RGB color |
You can change the RGB values stored in a pixel in most digital imaging software This is done by putting a new decimal representation of binary digits into the software. The range is 0 (zero intensity) to 255 (highest intensity) |
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Brightness |
A measurement for how close each pixel is to pure white.
Increased by adding values to each pixel |
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Contrast |
A measurement of the difference between the darkest and lightest portions of an image Adding or subtracting values will change the brightness but not this measurement Changing this measurement requires light pixels to become lighter and dark ones to become darker A formula can be used to find the average pixel color. Then you add or subtract from each individual pixel based on whether the pixel is lighter or darker than the average |
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Sound |
Created when vibrations in the air build a wave A special set of bones in our ear transmits this vibration when the wave reaches our eardrum Nerves in our in inner ear pick up the vibrations and our brain interprets the information |
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Volume |
Determined by the force or intensity of a sound
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Frequency |
The number of waves per second. This determines the pitch of a sound. |
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Analog |
A class of recording of sound that imprints the sound wave onto some sort of medium by measuring the change in air pressure as the sound wave passes by. |
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Sound Wave Graph |
A visual representation of sound. The horizontal axis is time and the vertical axis is sound pressure. |
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Digitizing Sound - the process |
- the information is transformed into memory bits - binary numbers are used to store the amount of the wave that is above or below the equilibrium or stable motion point of the wave - The computer stores the motion of the wave at a given point in time and can then use hardware to re-form the wave when needed |
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Samples |
Measurements taken of the sound wave at regular intervals |
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Sampling Rate |
The number of samples taken in a second when a computer is recording sound |
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Transducer |
A device that picks up sound and converts the sound wave into an electrical wave |
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Analog-to-digital Converter (ADC) |
Device that takes samples of an electrical wave (made from a sound wave) and converts the samples into digital values aka binary numbers |
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Compressor |
A machine that compresses binary numbers generated from an electrical wave that has captured sound and stores these numbers in memory |
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The entire process of recording sound |
1) A transducer picks up sound and converts it into an electrical wave 2) The electrical signal is fed into an analog-to-digital converter (ADC) which takes samples of the wave and converts the samples into digital values aka binary numbers 3) The binary numbers are then compressed by the compressor and stored in memory |
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Decompressor |
A machine that reads stored binary numbers storing "sound" information and re-formats them. |
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Digital to analog converter (DAC) |
A machine that creates an electrical wave by interpolation between digital values storing audio information |
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Speaker |
A machine that takes an electrical wave storing audio information and transmits sound |
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The process of playing a digital sound |
1) A decompressor reads the stored binary numbers from memory and re-formats them. 2) The numbers are sent to a digital to analog converter (DAC) which creates an electrical wave by interpolation between the digital values 3) The electrical wave is fed to a speaker which transmits the sound |
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Number of Pixels to make a decent quality print of an 8x10 photo |
900 by 1500 pixels per inch |
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Image compression |
A process that makes image files smaller thereby allowing us to transmit millions of images over the world wide web every day. This process changes the digital image in order to use fewer bits to store and transmit information |
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Run length encoding |
A compression process that can be used to transmit information about how many 0's are followed by how many 1's which are followed by how many zeros etc. This compression is lossless because no information is being lost along the way while space is being saved |
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Lossless compression |
A type of compression that does not lose information along the way Example: run length encoding |
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Lossy compression |
A method where information is lost in the process of compression. Example: JPEG images, which lose color information by recoloring neighboring pixels that are almost identical in color |
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JPEG image compression ratio |
10:1 without noticeable change in image quality |
