Pixel Graphics Flashcards
What does dpi stand for?
dots per inch
what does ppi stand for?
pixels per inch
what does lpi stand for?
lines per inch
What are pixels?
small squares that make up computer screens
what does each pixel contain?
red, green and blue intensity from 0 - 255
What is additive colour?
What are the primary additive colours?
What are additive colours used for?
What do additive colours form when combined?
colour based on light interaction
red, green, blue
used for computer screens
form grey when combined
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?
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.
What are the secondary additive colours?
the subtractive primary colours, cyan, magenta, yellow.
How is white formed?
by adding the primary and secondary additive colours together
what is hue?
how pigmented a colour is
what is saturation?
how vivid a colour is
how far away a colour is from grey
what is brightness
the overall intensity of a colour
what is spatial resolution?
refers to dimension, specifically pixels per inch
what happens when you increase spatial resolution?
things appear smaller and the screen appears larger.
what happens when you decrease spatial resolution?
things appear la.rger and the screen appears smaller
what is an example of spatial resolution?
1024 x 900
what are the dimensions for spatial resolution?
horizontal x vertical
what is pixel resolution?
the number of bits at each pixel.
What are the three graphics file formats?
GIF, PNG and JPEG
what are the compression types of the 3 file formats?
loss-less: PNG and GIF
lossy: JPEG
What are the colour types of the 3 file formats?
8-bit colour: GIF
True colour capable: PNG and JPEG
Which of the 3 file formats support animation?
GIF only.
What is lossy compression?
smaller file size but detail is lost
how do you use masking?
use a marquee tool to select a region, then the rest of the image is masked
what does feathering do?
applies a soft edge to a mask boundary
what does the level histogram show and what is it used for?
shows greyscale intensity vs the number of pixels that have that intensity
used to increase contrast by stretching the histogram
what is sharpening?
each pixel is replaced by a weighted sum of its neighbours to make edges more visible.
what do amount, threshold and radius refer to in terms of sharpening?
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
what is a layer?
a pixel grid; an individual and distinct painting
what is an adjustment layer?
a layer with an attached image transformation the adjustment may affect the entire image
