Path: utzoo!attcan!uunet!mcvax!enea!kth!luth!ulmo1.mt.luth.se!sow
From: sow@ulmo1.mt.luth.se (Sven-Ove Westberg)
Newsgroups: comp.graphics
Subject: Re: the word "bitmap"
Message-ID: <1304@luth.luth.se>
Date: 8 Jan 89 15:03:26 GMT
References: <450@orbit.UUCP> <1198@hydra.riacs.edu>
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Reply-To: Sven-Ove Westberg <sow@cad.luth.se>
Organization: University of Lulea, Sweden
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In article <1198@hydra.riacs.edu> julian@hydra.riacs.edu.UUCP (Julian E Gomez) writes:
|
|Like others have pointed out, "pixmap" seems like the best bet. We're
|already used to asking how many bits in a pixel, whereas we're not used
|to asking how many bits in a bit.

Pixmap is NOT the term we should use for this type of data structures.

From ISO/DIS 8613-7, "Information processing - text and office systems -
Office Document Architecture (ODA) and interchange format -

Part 7:
Raster graphics content architectures.


pel array: A two-dimensional array of pels (Picture Elements) used to
represent a pictorial image.

bitmap: A two- or three-dimensional data field representing a pel array.

In section 9.1 "Bitmap encoding scheme"

Each element in a pel array may have one of two distinct states.
These are the set state, corresponding to foreground colour and the
unset state, corresponding to the background colour. For the purpose of
representing such an array within a text unit, each pel may be
represented by a single bit which has the value '0' or '1' depending
on the state of that pel. .....


If the definition in the iso draft is valid then a bitmap can have
more then two distinct states. The third dimension.

But later in the encoding scheme it is clear that a bitmap is
a pel array with only two distinct states.

It is clear that a colour image is a pel array. But not what a bitmap is.

So let us use pel array.

Sven-Ove Westberg, CAD, University of Lulea, S-951 87 Lulea, Sweden.
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