What is an Image?
An image is a rectangular grid of pixels. It has a definite height
and a definite width counted in pixels. Each pixel is square and
has a fixed size on a given display. however different computer
monitors may use different sized pixels.
Each pixel has a color. The color is a 32-bit integer. The first
eight bits determine the redness of the pixel, the next eight bits
the greenness, the next eight bits the blueness, and the remaining
eight bits the transparency of the pixel.
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| Transparency |
Red |
Green |
Blue |
Each of these values can be interpreted as an unsigned byte
between 0 and 255. Within the color higher numbers are brighter.
Thus a red of 0 is no red at all while a red of 255 is a very
bright red.
Currently Java only supports two levels of transparency:
Completely opaque (255) and completely transparent (0). Values of 1
through 254 are treated as completely transparent.
Different colors are made by mixing different levels of the
three primary colors. For example, medium gray is 127 red, 127
green, and 127 blue.
Medium Grey
| 255 |
127 |
127 |
127 |
Pure white is 255 red, 255 green, 255 blue.
Bright White
| 255 |
255 |
255 |
255 |
Pure red is 255 red, 0 green, 0 blue.
A light cream is 255 red, 231 green, and 187 blue.
Light Cream
| 255 |
255 |
231 |
187 |