US 4,785,391 A · Automated bitmap character generation from outlines

Abstract

An outline representation of a character or symbol is treated as being composed of a hierarchy of zones formed in both the horizontal and vertical directions. The zones are completely character-specific. Each zone defines the extent of some feature of the character. The boundaries of the zones are mapped to specific pixel locations in a bitmap em-square of selected resolution and size. The available pixels are then allocated to the zones. After each level of zone has received its pixel allocation, the pixels assigned thereto are then distributed among the next lower level of zones and the process is repeated iteratively until all zones have received their pixel allocations or it is no longer possible to make allocations. To maintain relationships between features, features of characters (both within individual characters and between different characters) may be linked so as to be defined in terms of the features of the same or other characters. The features are linked at the outline description level, so that the linking need be specified only once and will thereafter be useful any time a bitmap is to be generated from the outline.

Claims40

Dependent claims

A method for use in generating from an outline representation of a character a bitmap representation therefor, at a selectable point size and resolution, the outline representation being defined relative to a high-resolution em-square and the bitmap representation being defined in terms of a low-resolution em-square, such method comprising the steps of:

a. defining, for at least one dimension, a plurality of zones within the high-resolution em-square, each zone corresponding to a typographic feature of the character;
and
b. arranging said zones into a hierarchy, with the position of each zone in the hierarchy corresponding substantially to the relative perceptual importance of the corresponding typographic feature.

A method for use in generating a low-resolution bitmap representation of each character in a character set at a selectable resolution and point size from an outline representation thereof relative to a high-resolution em-square, to provide low-resolution bitmap character representation of consistent and aesthetically pleasing appearance, said method comprising the steps of:

for each character in the set, slicing the em-square with respect to at least one dimension, to define a plurality of zones, each zone corresponding to a typographic feature of the character;
arranging the zones for each dimension of each character into a hierarchy with the position of each zone in the hierarchy corresponding to the relative importance of the corresponding typographic feature, the hierarchy of zones including at least one root zone and a plurality of daughter zones;
allocating to the root zone for each character an integral number of pixels which equals the number of pixels required to display the respective character at the selected point size on an output device of the selected resolution;
and
individually scaling the features of each character by allocating to each of the daughter zones a portion of the pixels allocated to the root zone.

2 more elements

A method for use in generating a low resolution bitmap representation of a character at a selectable resolution and point size form an outline representation thereof relative to a high-resolution em-square to provide a low-resolution bitmap character representation of consistent and aesthetically pleasing appearance comprising the steps of:

for at least one dimension of the character, slicing the em-square into a plurality of zones, each zone corresponding to a typographic feature of the character;
arranging the zones for each of the at least one dimensions of the character into a hierarchy with the position of each zone in the hierarchy corresponding to the relative importance of the corresponding typopgraphic feature, the hierarchy of zones including at least one root zone and a plurality of daughter zones;
allocating to the root zone an integral number of pixels which equals the number of pixels required to display the character of the selected point size on an output device of the selected resolution;
and
individually scaling the features of the character by allocating to each of the daughter zones a portion of the pixels allocated to the root zone.

2 more elements

Dependencies are inferred from the claim text.

Automated bitmap character generation from outlines

Life of this patent

Automated bitmap character generation from outlines

Life of this patent

Abstract

Claims40