Lecture 3 - Intro to Graphics Flashcards
What three aspects do we rely on images for?
- Information
- Explanations
- Entertainment
What do computers understand or “speak”?
Binary - series of 0’s and 1’s
What is Digitization?
The process of translating a piece of information into Binary Bits
What does 1 bit represent?
A max of 2 values.
- black and white
- true and false
What does 2 bits represent?
A max of 4 values
- black, dark grey, light grey and white
- red, blue, yellow and black
What does 3 bits represent?
A max of 8 values
- days of the week
- shades of grey
If a pixel color is represented by 1 bit then,
Value 0 =
Value 1 =
Value 0 = Black
Value 1 = White
How many colours can 2 bits allow for?
4 colours
How many colours can 4 bits represent?
2^4 therefore 16
More bits, means more colours available to assign to a pixel
How many colors are 6 bits?
64 possible colours
How many colors are 8 bits?
256 possible colours (think Crayon boxes)
How many colors are 24 bits?
Approximately 16 million possible colors
What is Sampling?
How many parts (pixels) will I break the image up into?
The more samples taken, the clearer the picture becomes
What color model is used for the web?
Additive Model (RGB)
The primary colors are Red, Green and Blue
Adding light to a black background in order to obtain color shades, it is brighter than CMYK
What color model is used for printing?
Subtractive Model (CMYK)
Primary colors are Cyan, Magenta and Yellow
What bit representation does “True Color” use?
24 bits which is approximately 16 million colors
Need 3 bytes for True Color
RGB Notation
Each pixel is represented by 3 values
Each value ranges from 0 to 255
Example: Light Yellow is 255, 255, 127
In RGB Notation, what are the colors Red, Green, Blue, White and Black?
Red: <255,0,0>
Green: <0,255,0>
Blue: <0,0,255>
White: <255,255,255>
Black: <0,0,0>
In Hexadecimal Notation, what are the colors Red, Green, Blue, Black, White, Dark Grey and Light Grey?
Red: #FF0000 Green: #00FF00 Blue: #0000FF Black: #000000 White: #FFFFFF Dark Grey: #222222 Light Grey: #CCCCCC
Case is insignificant when writing hexadecimal notation
Can you convert RGB to hexadecimal or vice versa?
YES
Approximately how many colors can the human eye detect?
10 million
How does being a Bitmap graphic or Vector graphic affect the display in a computer screen?
- Quality
- File Size
- Time to display the graphic
Bitmap Graphics (Raster)
Made up of pixels
Editing pixels = changing colors
Bitmapped images come from scanners and cameras etc
Interpolation
The computer adds new pixels and guesses on the color to color the new pixels based on the surrounding pixels
Quality decreases
File size increases
