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Pages and Files
Colors and images
Why is this important?
Any time you are involved in:
Developing web sites and applications
Digital imaging or digital photography
Scanning documents / archiving
(or Picture Element) is the smallest unit of color produced by a computer monitor. Thus,
pixels have become the de facto unit of measure for computer images (and colors).
is one horizontal row of pixels, representing one line of a computer monitor or image.
The range of colors that can be produced by mixing the primary colors available in the different
intensities available is known as the
For a good overview of this topic, see the
Note the two alternate representations: Hue, Saturation, Luminosity and Red, Green, Blue
is the color represented numerically (as going round a color wheel); Saturation is the "colorfulness" of a color; Luminosity is the brightness.
These are our two "main" ways to represent color: two systems each which needs three numbers:
- representation of primary colors separately.
- different way to project into RGB color space. See
more detailed tutorial
We also have systems for more specialized use
CMY and CMYK
- tuned for printing rather than for light
For a general overview of the different formats for storing images, see the
Comparison chart of image formats
. There are a variety of techniques generally used in image handling, particularly:
- you can even do this without a GPS, e.g.
Example basic Exif tagging:
JPEG vs GIF
There are plenty of Image converters e.g.
help on how to format text
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