US 6,324,300 B1 · Defining color borders in a raster image

Abstract

Disclosed is a method and apparatus for converting the color borders of a raster image into a more abstract mathematical representation that can be converted into a vector format without significantly fragmenting the image. The invention involves scanning a neighborhood of cells in the form of a square matrix through the raster image in order to generate a surface string (or an indicia thereof) representing the color border at each pixel, and then to sequence the surface strings into string sequences which represent the color borders. By assigning color values to the neighborhood of cells that indicate whether the perimeter cells are the same or different in color than the center cell, the present invention is capable of defining color borders in raster images comprising three or more colors (as opposed to black and white images). The string sequences are generated by sequencing together string IDs rather than simple slopes which provides optimal information for generating vectors. Another enabling aspect of the present invention is to sequence the surface strings according to a a priority assigned to surface strings based on their location in the image and their type (protruding corner, corner, step, etc.).

Claims48

Dependent claims

An apparatus for defining color borders in a raster image comprising a plurality of pixels, the apparatus comprising:

a system memory for storing the steps of a computer program;
and a computer processor connected to the system memory for executing the steps of the computer program,
wherein the computer program comprises:
(a) a string indicia generator responsive to a neighborhood of cells representing pixels of the raster image, wherein the string indicia generator outputs an indicia of a surface string representing a segment of a color border passing through at least part of the neighborhood of cells;
and
(b) a string sequencer for generating a string sequence representing a color border of the raster image by ordering a plurality of the indicia of surface strings based on a, predetermined criteria,
wherein:
each cell of the neighborhood of cells represents a color of a corresponding part of the raster image;
the neighborhood of cells comprises a target cell and a plurality of perimeter cells;
each perimeter cell comprises a color value selected from the set consisting of Y and Z;
Y indicates the color of the raster image represented by the perimeter cell is the same as the color of the raster image represented by the target cell;
and
Z indicates the color of the raster image represented by the perimeter cell is different than the color of the raster image represented by the target cell.

10 more elements

An apparatus for defining color borders in a raster image comprising a plurality of pixels, the apparatus comprising:

a system memory for storing the steps of a computer program;
and
a computer processor connected to the system memory for executing the steps of the computer program,
wherein the computer program comprises:
(a) a string indicia generator responsive to a neighborhood of cells representing pixels of the raster image, wherein the string indicia generator outputs an indicia of a surface string representing a segment of a color border passing through at least part of the neighborhood of cells;
and
(b) a string sequencer for generating a string sequence representing a color border of the raster image by ordering a plurality of the indicia of surface strings based on a predetermined criteria,
wherein:
a priority is associated with each indicia of a surface string;
and
the string sequencer orders the indicia of surface strings by comparing the priorities of the indicia and selecting the indicia having a predetermined priority to begin the string sequence.

8 more elements

An image processing integrated circuit for defining color borders in a raster image comprising

a plurality of pixels, the integrated circuit comprising:
(a) a string indicia generator responsive to a neighborhood of cells representing pixels of the raster image, wherein the string indicia generator outputs an indicia of a surface string representing a segment of a color border passing through at least part of the neighborhood of cells;
and
(b) a string sequencer for generating a string sequence representing a color border of the raster image by ordering a plurality of the indicia of surface strings based on a predetermined criteria,
wherein:
each cell of the neighborhood of cells represents a color of a corresponding part of the raster image;
the neighborhood of cells comprises a target cell and a plurality of perimeter cells;
each perimeter cell comprises a color value selected from the set consisting of Y and Z;
Y indicates the color of the raster image represented by the perimeter cell is the same as the color of the raster image represented by the target cell;
and
Z indicates the color of the raster image represented by the perimeter cell is different than the color of the raster image represented by the target cell.

8 more elements

A method of defining color borders in a raster image comprising a plurality of pixels, the method comprising the steps of:

(a) scanning a neighborhood of cells through the pixels of the raster image;
(b) generating an indicia of a surface string representing a segment of a color border passing through at least part of the neighborhood of cells;
and
(c) sequencing a plurality of the indicia of surface strings into a string sequence based on a Predetermined criteria, the string sequence representing a color border of the raster image,
wherein:
each cell of the neighborhood of cells represents a color a corresponding part of the raster image;
the neighborhood of cells comprises a target cell and a plurality of perimeter cells;
each perimeter cell comprises a color value selected from the set consisting of Y and Z;
Y indicates the color of the raster image represented by the perimeter cell is the same as the color of the raster image represented by the target cell;
and
Z indicates the color of the raster image represented by the perimeter cell is different than the color of the raster image represented by the target cell.

8 more elements

A computer program embodied on a computer-readable medium for defining color borders in a raster image comprising a plurality of pixels, the computer program comprising source code segments comprising:

(a) a string indicia generator responsive to a neighborhood of cells representing pixels of the raster image, wherein the string indicia generator outputs an indicia of a surface string representing a segment of a color border passing through at least part of the neighborhood of cells;
and
(b) a string sequencer for generating a string sequence representing a color border of the raster image by ordering a plurality of the indicia of surface strings based on a predetermined criteria,
wherein:
each cell of the neighborhood of cells represents a color of a corresponding part of the raster image;
the neighborhood of cells comprises a target cell and a plurality of perimeter cells;
each perimeter cell comprises a color value selected from the set consisting of Y and Z;
Y indicates the color of the raster image represented by the perimeter cell is the same as the color of the raster image represented by the target cell;
Z indicates the color of the raster image represented by the perimeter cell is different than the color of the raster image represented by the target cell.

6 more elements

Dependencies are inferred from the claim text.

Defining color borders in a raster image

Life of this patent

Defining color borders in a raster image

Life of this patent

Abstract

Claims48