Method for enhancing raster pixel data

• US 5,249,242 A
• Filed: 12/23/1991
• Issued: 09/28/1993
• Est. Priority Date: 12/23/1991
• Status: Expired due to Term

• Current Assignee: Adobe Systems Incorporated (Adobe Inc.)
• Original Assignee: Adobe Systems Incorporated (Adobe Inc.)
• Inventors: Hanson, William J., Love, Richard I., Putman, R. Daniel
• Primary Examiner(s): Mancuso, Joseph
• Application Number:
  US07/813,203
• Time in Patent Office: 645 Days
• Field of Search: 382/25, 382/27, 382/54, 382/49, 382/55, 358/447, 358/455, 358/456
• US Class Current: 382/269
• CPC Class Codes: F02B 2075/027 four
• CPC Class Codes: G06K 15/00 Arrangements for producing a permanent visual presentation of the output data , e.g. computer output printersprinting or plotting combined with another operation, e.g. with conveying, G06K17/00
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 2215/006 Anti-aliasing raster data
• CPC Class Codes: G06K 2215/0071 Post-treatment of the composed image, e.g. compression, rotation
• CPC Class Codes: G06T 5/20 using local operators

Abstract

Briefly, the invention provides a method of enhancing pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems. The method commences by applying a window to a portion of the raster pixel data from the raster images to define a block of raster pixel data having a predetermined area. The pattern of the block of raster data within the window is then compared with a plurality of predetermined patterns representing morphological artifacts. A determination is made from the comparison whether a substantial match exists between the block of raster data within the window and one or more of the plurality of predetermined patterns. In the event of a match the block of raster data is modified to provide an enhanced block of raster pixel data free of said morphological artifacts. Finally, the window is applied to a different block of raster data and the process is repeated until all of the raster data is free from the undesired morphological artifacts.

Claims

1. A method of enhancing raster pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems, comprising:

applying a window to a portion of said raster pixel data from said raster image to define a block of said raster pixel data having a predetermined area which may contain morphological artifacts;

comparing the pattern of said raster data within said window with a plurality of predetermined patterns representing morphological artifacts;

determining from said comparison whether a substantial match exists between said block of raster pixel data within said window and one or more of said plurality of predetermined patterns representing morphological artifacts;

in the event of a match, modifying at least a portion of said raster pixel data to provide an enhanced block of raster pixel data with improved appearance which de-emphasizes said morphological artifacts; and

applying said window to a different block of raster pixel data and repeating the process.

2. A method of enhancing raster pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems, comprising:

applying a window to a portion of said raster pixel data from said raster image to define a block of said raster pixel data having a predetermined area which may contain morphological artifacts;

comparing the pattern of said raster data within said window with a plurality of predetermined patterns representing morphological artifacts;

determining from said comparison whether a substantial match exists between said block of raster pixel data within said window and one or more of said plurality of predetermined patterns representing morphological artifacts;

in the event of a match, modifying at least a portion of said raster pixel data to provide an enhanced block of raster pixel data with improved appearance which de-emphasizes said morphological artifacts; and

moving said window across the pixel map of said raster image and repeating the process.

3. A method of enhancing raster pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems, comprising:

applying a window to a portion of said raster pixel data from said raster image to define a block of said raster pixel data having a predetermined area which may contain morphological artifacts;

comparing the pattern of said raster data within said window with a plurality of predetermined patterns representing morphological artifacts;

determining from said comparison whether a substantial match exists between said block of raster pixel data within said window and one or more of said plurality of predetermined patterns representing morphological artifacts;

in the event of a match, modifying at least a portion of said raster pixel data to provide an enhanced block of raster pixel data with improved appearance which de-emphasizes said morphological artifacts; and

moving said window down the page in raster line sequence and repeating the process.

4. A method of enhancing raster pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems, comprising:

applying a window to a portion of said raster pixel data from said raster image to define a block of said raster pixel data having a predetermined area located within a predetermined band of raster scan lines which may contain morphological artifacts;

comparing the pattern of said raster data within said window with a plurality of predetermined patterns representing morphological artifacts;

determining from said comparison whether a substantial match exists between said block of raster pixel data within said window and one or more of said plurality of predetermined patterns representing morphological artifacts;

in the event of a match, modifying at least a portion of said raster pixel data to provide an enhanced block of raster pixel data with improved appearance which de-emphasizes said morphological artifacts;

moving said window across the pixel map of said raster image and repeating the process; and

moving said window down the page in raster line sequence and repeating the process.

5. Apparatus for enhancing raster pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems, comprising:

means for applying a window to a portion of said raster pixel data from said raster image to define a block of said raster pixel data having a predetermined area which may contain morphological artifacts;

means for comparing the pattern of said raster data within said window with a plurality of predetermined patterns representing morphological artifacts;

means for determining from said comparison whether a substantial match exists between said block of raster pixel data within said window and one or more of said plurality of predetermined patterns representing morphological artifacts;

means for modifying, in the event of a match, at least a portion of said raster pixel data to provide an enhanced block of raster pixel data with improved appearance which de-emphasizes said morphological artifacts; and

means for applying said window to a different block of raster pixel data and repeating the process.

6. Apparatus for enhancing raster pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems, comprising:

means for applying a window to a portion of said raster pixel data from said raster image to define a block of said raster pixel data having a predetermined area which may contain morphological artifacts;

means for comparing the pattern of said raster data within said window with a plurality of predetermined patterns representing morphological artifacts;

means for determining from said comparison whether a substantial match exists between said block of raster pixel data within said window and one or more of said plurality of predetermined patterns representing morphological artifacts;

means for modifying, in the event of a match, at least a portion of said raster pixel data to provide an enhanced block of raster pixel data with improved appearance which de-emphasizes said morphological artifacts; and

means for moving said window across the pixel map of said raster image and repeating the process.

7. Apparatus for enhancing raster pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems, comprising:

means for applying a window to a portion of said raster pixel data from said raster image to define a block of said raster pixel data having a predetermined area which may contain morphological artifacts;

means for comparing the pattern of said raster data within said window with a plurality of predetermined patterns representing morphological artifacts;

means for determining from said comparison whether a substantial match exists between said block of raster pixel data within said window and one or more of said plurality of predetermined patterns representing morphological artifacts;

means for modifying, in the event of a match, at least a portion of said raster pixel data to provide an enhanced block of raster pixel data with improved appearance which de-emphasizes said morphological artifacts; and

means for moving said window down the page in raster line sequence and repeating the process.

8. Apparatus for enhancing raster pixel data from a raster image to improve the appearance of the rendered image by modifying morphological artifacts which normally occur in raster image systems, comprising:

means for applying a window to a portion of said raster pixel data from said raster image to define a block of said raster pixel data having a predetermined area located within a predetermined band of raster scan lines which may contain morphological artifacts;

means for comparing the pattern of said raster data within said window with a plurality of predetermined patterns representing morphological artifacts;

means for determining from said comparison whether a substantial match exists between said block of raster pixel data within said window and one or more of said plurality of predetermined patterns representing morphological artifacts;

means for modifying, in the event of a match, at least a portion of said raster pixel data to provide an enhanced block of raster pixel data with improved appearance which de-emphasizes said morphological artifacts; and

means for moving said window across the pixel map of said raster image and repeating the process; and

means for moving said window down the page in raster line sequence and repeating the process.