Pixel Graphics

Question 1

What does dpi stand for?

Answer 1

dots per inch

Question 2

what does ppi stand for?

Answer 2

pixels per inch

Question 3

what does lpi stand for?

Answer 3

lines per inch

Question 4

What are pixels?

Answer 4

small squares that make up computer screens

Question 5

what does each pixel contain?

Answer 5

red, green and blue intensity from 0 - 255

Question 6

What is additive colour?
What are the primary additive colours?
What are additive colours used for?
What do additive colours form when combined?

Answer 6

colour based on light interaction
red, green, blue
used for computer screens
form grey when combined

Question 7

What is subtractive colour?
What are the primary subtractive colours?
What are subtractive colours used for?
What do additive colours form when combined?
How are subtractive colours formed?

Answer 7

colour based on light absorption
cyan, magenta, yellow
used for printing
form black when combined
formed by adding additive colours together or subtracting them from white.

Question 8

What are the secondary additive colours?

Answer 8

the subtractive primary colours, cyan, magenta, yellow.

Question 9

How is white formed?

Answer 9

by adding the primary and secondary additive colours together

Question 10

what is hue?

Answer 10

how pigmented a colour is

Question 11

what is saturation?

Answer 11

how vivid a colour is
how far away a colour is from grey

Question 12

what is brightness

Answer 12

the overall intensity of a colour

Question 13

what is spatial resolution?

Answer 13

refers to dimension, specifically pixels per inch

Question 14

what happens when you increase spatial resolution?

Answer 14

things appear smaller and the screen appears larger.

Question 15

what happens when you decrease spatial resolution?

Answer 15

things appear la.rger and the screen appears smaller

Question 16

what is an example of spatial resolution?

Answer 16

1024 x 900

Question 17

what are the dimensions for spatial resolution?

Answer 17

horizontal x vertical

Question 18

what is pixel resolution?

Answer 18

the number of bits at each pixel.

Question 19

What are the three graphics file formats?

Answer 19

GIF, PNG and JPEG

Question 20

what are the compression types of the 3 file formats?

Answer 20

loss-less: PNG and GIF
lossy: JPEG

Question 21

What are the colour types of the 3 file formats?

Answer 21

8-bit colour: GIF
True colour capable: PNG and JPEG

Question 22

Which of the 3 file formats support animation?

Answer 22

GIF only.

Question 23

What is lossy compression?

Answer 23

smaller file size but detail is lost

Question 24

how do you use masking?

Answer 24

use a marquee tool to select a region, then the rest of the image is masked

Question 25

what does feathering do?

Answer 25

applies a soft edge to a mask boundary

Question 26

what does the level histogram show and what is it used for?

Answer 26

shows greyscale intensity vs the number of pixels that have that intensity
used to increase contrast by stretching the histogram

Question 27

what is sharpening?

Answer 27

each pixel is replaced by a weighted sum of its neighbours to make edges more visible.

Question 28

what do amount, threshold and radius refer to in terms of sharpening?

Answer 28

amount: how much to sharpen
threshold: by how much adjacent pixels must differ in order to be sharpened
radius: the width in pixels of the effect on either side of an edge

Question 29

what is a layer?

Answer 29

a pixel grid; an individual and distinct painting

Question 30

what is an adjustment layer?

Answer 30

a layer with an attached image transformation the adjustment may affect the entire image