Method for color image reduction based upon determination of color components of pixels in neighboring blocks

• US 5,355,447 A
• Filed: 07/31/1992
• Issued: 10/11/1994
• Est. Priority Date: 05/27/1988
• Status: Expired due to Term

• Current Assignee: Ip Ot Sub Ulc
• Original Assignee: Wang Laboratories Incorporated
• Inventors: Knowlton, Kenneth C.
• Primary Examiner(s): Herndon, Heather R.
• Assistant Examiner(s): Breene, John E.
• Application Number:
  US07/922,403
• Time in Patent Office: 802 Days
• Field of Search: 395/128-129, 395/131, 395/139, 395/155-161, 340/703, 340/731, 340/706, 382/47, 382/54, 382/52, 345/149-153, 345/129, 345/136, 345/127, 345/89, 364/526, 358/17, 358/22, 358/30, 355/32, 355/88, 355/133, 355/327
• US Class Current: 345/670
• CPC Class Codes: G06F 3/033 Pointing devices displaced or positioned by the user , e.g. mice, trackballs, pens or joysticks; Accessories therefor digitisers characterised by the transducing means G06F3/041
• CPC Class Codes: G06F 3/04817 using icons graphical or visual programming using iconic symbols G06F8/34
• CPC Class Codes: G06F 3/0483 Interaction with page-structured environments, e.g. book metaphor
• CPC Class Codes: G06F 40/169 Annotation, e.g. comment data or footnotes
• CPC Class Codes: G06Q 10/10 Office automation; Time management

Abstract

A data processing system provides a desk view which serves as a graphical user interface to the system. The desk view displays detailed miniaturized images of all documents possessed by the user. The compressed document images are user moveable and stackable in the desk view. The desk view also enables user selected operations including mailing, disposing, annotating, stapling, unstapling and printing of documents. User interaction with items of the desk view is communicated through an electronic-stylus. Different actions with the stylus provide naturally expected effects. The stylus and desk view provide a simulation of a common office desk and user interaction therewith.

Claims

1. A method of making a reduced image of an original two-dimensional pixel image, each pixel being defined by three components each having a value which together define a corresponding point at a position in a 3-D color space, said 3-D color space comprising a plurality of said points each of which defines a unique color, the method comprising:

dividing the original image into blocks, each block of the original image having a plurality of pixels, each block corresponding to a pixel in the reduced image;

for each block,

determining if all pixels are equal to a first color in a block and, if so, making the corresponding pixel in the reduced image equal to the first color in said block;

if all pixels are not equal to the first color in said block,

determining if a unique identifiable background color is present in a plurality of blocks adjacent to said block;

if a unique identifiable background color is present,

identifying a first point in said color space related to an average value of the components of said pixels comprising said block;

identifying a second point in said color space related to said background color, said second point differing from said first point by a first distance; and

selecting as the color of the corresponding pixel in the reduced image, a color having a position in said 3-D color space which differs from said second point by an amount greater than said first distance.

2. The method according to claim 1 and further including representing each pixel with a byte value, said byte value having associated therewith said three components and storing said components in a lookup table addressable by said byte values and wherein said step of determining if all pixels are equal to a first color comprises determining if all pixels are equal to a first byte value.

3. The method as set forth in claim 2 wherein the adjacent blocks include all contiguous blocks.

4. The method according to claim 1 wherein said step of determining if there is a unique identifiable background color comprises the steps of determining if said surrounding blocks are single color blocks and, if said blocks are single color blocks, whether the colors of all of said blocks are the same and, if so, designating that color as the unique color and, if no adjacent blocks are single color blocks or have different single colors, determining that no unique identifiable background color is present.

5. The method according to claims 4 wherein said components comprise various intensities of red, green, and blue.

6. The method according to claims 1 wherein said components comprise various intensities of red, green, and blue.

7. A method of making a reduced image of an original two-dimensional pixel image, each pixel being defined by three components each having a value which together define a corresponding point at a position in a 3-D color space, said 3-D color space comprising a plurality of said points each of which defines a unique color, the method comprising:

dividing the original image into blocks, each block of the original image having a plurality of pixels, each block corresponding to a pixel in the reduced image;

for each block,

determining if all pixels are equal to a first color in a block and, if so, making the corresponding pixel in the reduced image equal to the first color in said block;

if all pixels are not equal to the first color in said block,

determining if a unique identifiable background color is present in a plurality of blocks adjacent to said block;

if a unique identifiable background color is present,

identifying a first point in said color space related to an average value of the components of said pixels comprising said block;

identifying a second point in said color space related to said background color, said second point differing from said first point by a first distance; and

selecting as the color of the corresponding pixel in the reduced image, a color having a position in said 3-D color space which differs from said second point by an amount greater than said first distance;

if a unique identifiable background color is not present,

determining an average of each of said three components of said block; and

selecting as the color of the corresponding pixel of the reduced image, a color having a position in said 3-D color space corresponding to the three averaged components of said block.

8. The method according to claim 7 wherein the step of determining said average comprises determining the components of each of said pixels in said block, summing corresponding components and scaling said components.

9. The method as set forth in claim 8 comprising the additional step of dividing a sum of the corresponding components by a number equal to the plurality of pixels of the original block.

10. The method according to claim 8 and further including the step of representing each color with a byte value, each byte value having associated therewith a component on an orthogonal axis in said 3-D color space and storing said components in a lookup table addressable by said byte values and wherein said step of determining the components comprises obtaining said components from said lookup table.

11. The method of claim 10 and further including the step of converting the selected color of each pixel of said reduced image to a plurality of byte values.

12. A method of making a reduced image of an original two-dimensional pixel image, each pixel being defined by three components each having a value which together define a corresponding point at a position in a 3-D color space, said 3-D color space comprising a plurality of said points each of which defines a unique color, the method comprising:

dividing the original image into blocks, each block of the original image having a plurality of pixels, each block corresponding to a pixel in the reduced image;

for each block,

determining if all pixels are equal to a first color in a block by selecting one pixel within the block and comparing all other pixels to the selected one pixel to determine if other pixels are equal and, if so, making the corresponding pixel in the reduced image equal to the first color in said block;

if all pixels are not equal to the first color in said block,

determining if a unique identifiable background color is present in a plurality of blocks adjacent to said block;

if a unique identifiable background color is present,

identifying a first point in said color space related to an average value of the components of said pixels comprising said block;

identifying a second point in said color space related to said background color, said second point differing from said first point by a first distance which indicates a first color contrast; and

selecting as the color of the corresponding pixel in the reduced image, a color having a position in said 3-D color space which differs from said second point by an amount that provides greater color contrast to the background color than the first color contrast between the color at the first point and the background color.

13. The method as set forth in claim 12 wherein the step of determining if a unique identifiable background color is present in the plurality of blocks adjacent to said block comprises the step of, testing adjacent blocks to identify one solid color adjacent block, or two or more solid color adjacent blocks of equal color, and setting the background color to that of the one solid block, or to that of the two or more solid color blocks of equal color.

14. The method as set forth in claim 12, wherein the selected color differs from said first point by an amount greater than said first distance.

15. The method according to claims 14 wherein said components comprise various intensities of red, green, and blue.

16. A method of making a reduced image of an original two-dimensional pixel image, each pixel having associated therewith three components together defining a color for said pixel from a predefined set of colors, the method comprising,

dividing the original image into blocks, each block of the original image having a plurality of pixels, each block corresponding to a pixel in the reduced image, and

for each block in which all pixels have a color to a first color, making the corresponding pixel in the reduced image the first color,

for each block in which the pixels have colors corresponding to two or more colors, determining if a plurality of adjacent blocks together define a background color and, if so, then determining an average value for each of said three components of the pixels comprising said block to form a first set of component values, determining a second set of component values corresponding to the background color, said first set of component values differing from said second set component values by a first difference value, and determining for said pixel in the reduced image a color having a third set of component values which differ from said second set of component values by a value greater than said difference value.