Title: Theory / Unimportant / CS / Algo / Graphics / Fundamentals -Shirley Marschner{ / 03 Raster
Tags: récupéré MissingMedia

Name: pictured element
Page: 53
Chapter: 3
Abbreviation: pixel

Name: Raster display
Definition: Some thing which show images as rectangular arrays of pixel
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Chapter: 3
Example: flat-panel computer display or television
Example2: Most printers, such as laser printers and ink-jet printers

Name: Raster image
Definition: a 2D array that stores the pixel value for each pixel
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Chapter: 3

Question: What break link between raster image and raster display ?
Answer: We want to show raster image on raster display even when they have different sizes
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Chapter: 3

Name: A vector image
Definition: An image described by storing descriptions of shapes—areas of color bounded by lines or curves—with no reference to any particular pixel grid.
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Chapter: 3

Question: Main advantage of vector image
Answer: They are resolution independent
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Chapter: 3

Question: Kind of output raster device
Answer: Display (screen)
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Chapter: 3
Section: 1
Answer2: Hardcopy (printer)

Question: Kind of display output raster device
Answer: transmissive:liquid crystal display (LCD)
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Chapter: 3
Section: 1
Answer2: Emissive: light emitting diode (LED) display

Question: Kind of input raster device
Answer: 2D array sensor: digital camera
1D array sensor: flatbed scanner
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Chapter: 3
Section: 1

Name: Emissive display
Definition: A display which use pixels that directly emit controllable amounts of light
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Chapter: 3
Section: 1.1
Example: LED

Name: Transimissive display
Definition: Display in which the pixels themselves don’t emit light but instead vary the amount of light that they allow to pass through them.
Page: 54
Chapter: 3
Section: 1.1
Example: LCD

Name: backlight
Definition: A light behind a transmissive display, which allow to see the display's content
Page: 55
Chapter: 3
Section: 1.1

Name: Light-emitting diode
Definition: semiconductor devices (based on inorganic or organic semiconductors) that emit light with intensity depending on the electrical current passing through them
Page: 55
Chapter: 3
Section: 1.1
Abbreviation: LED

Question: How are LCD turned on and off ?
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Chapter: 3
Section: 1.1

Name: Liquid Cristal
Definition: A material whose molecular structure enables it to rotate the polarization of light that passes through it, and the degree of rotation can be adjusted by an applied voltage
Page: 56
Chapter: 3
Section: 1.1
Abbreviation: LCD

Name: LCD pixel
Definition: Two layer of polarizing film, rotated by 90 degrees, and some liquid cristal between them
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Chapter: 3
Section: 1.1
Abbreviation: LCD

Name: Liquid Cristal Display
Definition: A display based on LCD pixel
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Chapter: 3
Section: 1.1
Abbreviation: LCD

Name: Hardcopy device
Definition: A device printing image permanently on a surface
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Chapter: 3
Section: 1.2

Name: Binary image
Definition: An image defined by pigment present or absent at each point,
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Chapter: 3
Section: 1.2

Question: How ink-jet printer prints
Answer: The head moves across the paper, and drops are emitted as it passes grid positions that should receive ink; no ink is emitted in areas intended to remain blank.
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Chapter: 3
Section: 1.2

Question: How color ink-jet printer works
Answer: similar to black ink-jet, but with one head by color
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Chapter: 3
Section: 1.2

Question: What determines a ink-jet printer resolution ?
Answer: Size of the drop
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Chapter: 3
Section: 1.2
Answer2: Advancement of the paper at each sweep

Name: Continuous tone
Definition: Varying amounts of dye can be deposited at each pixel
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Chapter: 3
Section: 1.2
Example: Thermal dye transfer

Name: Thermal dye transfer
Definition: A donor ribbon containing colored dye is pressed between the paper, or dye receiver, and a print head containing a linear array of heating elements, one for each column of pixels in the image. As the paper and ribbon move past the head, the heating elements switch on and off to heat the ribbon in areas where dye is desired, causing the dye to diffuse from the ribbon to the paper. This process is repeated for each of several dye colors.
Page: 57
Chapter: 3
Section: 1.2

Question: How to control intensity of thermal dye transfer
Answer: control heat of the transfer
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Chapter: 3
Section: 1.2

Question: What determines resolution of thermal dye transfer
Answer: The number of heat element
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Section: 1.2
Answer2: Speed paper

Name: pixel per inch
Definition: The number of pixel corresponding to an inch of dye reciver
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Chapter: 3
Section: 1.2
Abbreviation: ppi

Name: dot per inch
Definition: The number of binary dot the printer can output to an inch of dye reciver
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Chapter: 3
Section: 1.2
Abbreviation: dpi

Name: pixel density
Definition: How many pixel are shown in some fixed unit of surface
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Chapter: 3
Section: 1.2

Question: Difference between dpi and ppi
Answer: dpi is for binary printer and ppi for continuous one
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Chapter: 3
Section: 1.2

Name: Halftones
Definition: intermediate color printed using varying density dot pattern
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Chapter: 3
Section: 1.2