Rolling changes from the discussion in #10

[minnerbe]

As discussed in #10, this is a PR with all changes that we agreed upon, so far. As the discussion progresses, I'll track all future changes in this PR.

[mkitti]

Suggested change

	A set of numbers intended to be displayed on a screen. It is also a set of values, each of which is associated with a position in a *domain*. Ancillary data structures may be required to display or interpret an *image* (such as a lookup table), but these are not part of the *image* itself. An *image* is often, but not necessarily, acquired by a sensor situated within an optical system. *Images* can be represented in compact forms, for example as a compressed sequence of bytes or as a discrete function over a finite domain, but these are not canonical uses of the word “image”, and the word “image” by itself should refer only to *arrays* and array-like data structures.
	A visual representation of a physical object or physical area of space.
	A *digital image* can be represented by a set of numbers intended to be displayed on a screen. Each number is associated with a position in a *domain*. Ancillary data structures may be required to display or interpret a *digital image* (such as a lookup table), but these are not part of the *image* itself. An *image* is often, but not necessarily, acquired by a sensor situated within a physical system such as an optical light microscope.
	*Digital images* can be represented in compact forms, for example as a compressed sequence of bytes or as a discrete function over a finite domain. In the data standards here, the word “image” by itself refers only to *arrays* and array-like data structures that represent a digital image rastered over space. Unless otherwise specified, this rastering occurs at regular equispaced intervals, the pixel pitch.