Color trapping for an image forming apparatus
AssigneeLexmark International, Inc.
InventorsDavid K. Lane, Ning Ren
Life of this patent
Estimating the term…
Abstract
The present invention is directed a method of color trapping. In one embodiment, the color trapping is performed during the rasterization process. The color trapping comprises identifying page objects into a variety of different categories. Color trapping for each of the page objects is then performed based on specific procedures for the category. In one embodiment, the categories include identifying the page objects as rectangles, characters, and non-rectangular shapes. In one embodiment, specific page objects may be identified as being of a type that color trapping is not to be performed.
Claims40
A method of color trapping page objects in an image forming apparatus comprising the steps of:
- a) receiving a page object in a page description at an image forming controller, the page description defining the page object as either edge lists or a bitmap;
- b) performing a first trapping technique when the page description defines the page object as the edge lists;
- and
- c) performing a second trapping technique when the page description defines the page object as the bitmap.
A method of color trapping within an image forming apparatus comprising:
- a) receiving a request comprising a page object that is executable by a image forming controller;
- b) identifying a category of the page object as being one of a character, rectangle, and non-rectangular shape;
- c) determining that trapping is necessary for the page object;
- and
- d) performing trapping according to the category of the page object,
- wherein the step of identifying the category of the page object comprises identifying the character by a bitmap.
A method of color trapping page objects during a rasterization process comprising the steps of:
- a) receiving a page object at an image forming controller;
- b) categorizing the page object into one of a first category or a second category;
- c) when the page object is categorized into the first category, performing color trapping using edge lists of the page object;
- and
- d) when the page object is categorized into the second category, performing color trapping using a bitmap of the page object.
A method of performing color trapping of a character comprising:
- a) obtaining a bitmap of a character;
- b) producing a modified bitmap of the character;
- c) selecting either the bitmap or the modified bitmap as the foreground representation;
- and
- d) selecting the other of the bitmap or the modified bitmap as the background representation.
A method of performing color trapping of a character comprising the steps of:
- a) obtaining a bitmap representation of a character;
- b) producing a first modified bitmap representation of the character;
- c) producing a second modified bitmap representation of the character;
- d) selecting one of the first and second modified bitmap representations of the character as a foreground representation;
- and
- e) selecting the other of the first and second modified bitmap representations of the character as a background representation.
A method of performing color trapping of a rectangle comprising the steps of:
- a) obtaining a height and a width of a rectangle;
- b) producing a modified height and a modified width of the rectangle;
- c) selecting one of the height and the width or the modified height and the modified width as a foreground representation;
- and
- d) selecting the other of the height and the width or the modified height and modified width as a background representation.
A method of performing color trapping of a rectangle comprising the steps of:
- a) obtaining a height and a width of a rectangle;
- b) producing a first dimension of the rectangle comprising a first modified height and a first modified width;
- c) producing a second dimension of the rectangle comprising a second modified height and a second modified width of the rectangle;
- d) selecting one of the first dimension and the second dimension as a foreground representation of the rectangle;
- and
- e) selecting the other of the first dimension and the second dimensions as a background representation of the rectangle.
A method of performing color trapping of a non-rectangular shape comprising:
- a) obtaining edge lists representing a non-rectangular shape;
- b) producing modified edge lists representing the non-rectangular shape;
- c) selecting either the edge lists or the modified edge lists as the foreground representation;
- and
- d) selecting the other of the edge lists or the modified edge lists as the background representation.
A method of performing color trapping of a non-rectangular shape comprising the steps of:
- a) obtaining edge lists representing a non-rectangular shape;
- b) producing first modified edge lists representing the non-rectangular shape;
- c) producing second modified edge lists representing the non-rectangular shape;
- d) selecting one of the first and second modified edge lists of the non-rectangular shape as a foreground representation;
- and
- e) selecting the other of the first and second modified edge lists of the non-rectangular shape as a background representation.
Dependencies are inferred from the claim text.