graphics and media Flashcards
when is the test date?
oct 21
details
30min
open book
answer 47 questions MC
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what is a pixel?
a pixel is a picture element
- the smallest unit of information about a picture
what are primary colours?
red green blue (RGB, standard)
what number does every pixel extend to
every pixel has a 24-bpp depth/ extends by 24-bpp number
what does #0A1CF3 mean?
0A for Red, 1C for green, F3 for blue, or the HTML color
what is the resolution of an image/display?
the total number of pixels represented
- typically horizontal (width) x vertical (height) number of pixels
what is the size of a full HD TV resolution?
1920pixels width, 1080 pixels height
today, how much can a digital camera capture?
16M(4000x4000) pixels of 24-bpp RGB (16M) colors
what is pixel density?
deifines the physical size of each pixel
- a TV has 100 ppi; an iPhone 5 has 326 ppi
what is pixel density (pixel-per-inch or ppi) ?
defines the physical size of each pixel
- a TV has 100 ppi; an iPhone 5 has 326 ppi
how does ppi affect the display affect the image/text
the higher the ppi fo a display, the sharper the image/text
what is meta-data inside an image file?
the data about the image itself
what does the amplitude refer to?
the larger the change in air pressure, the LOUDER the sound
what does the frequency refer to?
the faster the change in air pressure, the HIGHER PITCH the sound
what are bit-mapped fonts?
early fonts that are fix-sized and not easily scalable
what are outline fonts?
they are scalable and are display resolution independent
what is a postscript?
a technology invented by Adobe used by laser printers and GUI for printing or displaying outline fonts
what benefit does having scalable outline fonts bring?
thanks to scalable outline fonts, texts on our displays and printers are looking much better
what are common media formats?
- WAV, MP3 and AAC are audio formats
- GIF, PNG and JPEG are image formats
- WMV, MP4 and AVCHD are video formats
give 3 examples of common audio formats
WAV, MP3 and AAC
give 3 examples of common image formats
GIF, PNG and JPEG
give 3 examples of common video formats
WMV, MP4 and AVCHD
how are binary numbers represented?
inside a computer, all data are represented in binary, including numbers. A binary digit (or a bit) consists of two values: 0 and 1
- any number can be represented in binary
what is ASCII (American Standard Code for Information Interchange)?
uses 7-bits to encode all standard keyboard characters
what is UTF-8 (aka Unicode)?
an extension of ASCII using multi-bytes to encode all international character sets, including ASCII, Chinese, etc.
what does plain text mean?
that the character encoding is either ASCII or UTF-8
- HTML files are all plain text files using UTF-8 encoding
- a plain text cannot specify font family, size or bold etc.
what does colour-depth (bpp) affect?
the overall texture/details of an image
what is a motion picture?
a collection of pictures made to look like a video by capturing and playing images at a fixed number of frames per second.
what is data compression?
a technology to “squeeze” data to take up less space
what is lossless and lossy data compression?
lossless: preserves all data integrity
lossy: keeps as much “details” as possible
what is a common format for lossless data compression?
ZIP
- supported by windows and OS X by default
what is apple lossless?
a lossless compressed audio format; PNG and TIFF are a lossless compressed image format
explain vector graphics
a vector graphic model is scalable, thus zoomable. Today, many computers models are using 3D vector graphics. Hence, you can rotate the model and view from different angles. They are synthesized by computer internally, not pictures of the real world
