Browse Prior Art Database

2-D COMPRESSION OF WINDOW EFFECTS

IP.com Disclosure Number: IPCOM000026993D
Original Publication Date: 1994-Oct-31
Included in the Prior Art Database: 2004-Apr-07
Document File: 6 page(s) / 173K

Publishing Venue

Xerox Disclosure Journal

Abstract

In typical image processing circuitry, used in scanning environments, windowing (the application of an image processing function to a particular group of pixels) is controlled either through a series of counters, comparators, and effect storage blocks used to generate rectangular windows or through a large block of memory used as a mask to be applied over the input video to determine the required effect for a particular pixel. Neither of these approaches represent an ideal solution for the generation of window effects in a scanner environment.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 56% of the total text.

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XEROX DISCLOSURE JOURNAL

2-D COMPRESSION OF WINDOW EFFECTS US. (21.3581474 Anthony F. Calarco

Proposed Classification Int. C1. H04n 1/40

Block 1

Block 2

Block 3

Block 4

Block 5

XEROX DISCLOSURE JOURNAL - Vol. 19, No. 5 Septernber/October 1994 407

FIG. I

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2-D COMPRESSION OF WINDOW EFFECTS(Cont'd)

24

26

Power Up

Page Active No

Fetch and Execute

Yes

J- Set

  Start Address Pointer to End Address + 1

  Pointer to Start Address +

Off set

Active Page OJ

Block Instruction

Stop and Wait

lz2

Instruction

  Fetch Block Instruction from Stack

Page Next for c

FIG. 2

F/G. 3

408 XEROX DISCLOSURE JOURNAL - Vol. 19, No. 5 September/October 1994

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2-D COMPRESSION OF WINDOW EFFECTStCont'd)

{Enter Fast Scan L50

Instruction

rr

  Reset Fast Scan Instruction Pointer to

? Active Start of Block

564-1 Scan Fetch Instruction Next Fast

from Stack

584-1 Effect Register

60

L

'54

Load Fast Scan Length counter with Instruction Length & Enabel Count

Block ?

Exit Fast Scan

Instruction )

XEROX DISCLOSURE JOURNAL - Vol. 19, No. 5 Septernber/October 1994 409

62

64

e

No

FIG. 4

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Page 4 of 6

2-D COMPRESSION OF WINDOW EFFECTS(Cont'd)

In typical image processing circuitry, used in scanning environments, windowing (the application of an image processing function to a particular group of pixels) is controlled either through a series of counters, comparators, and effect storage blocks used to generate rectangular windows or through a large block of memory used as a mask to be applied over the input video to determine the required effect for a particular pixel. Neither of these approaches represent an ideal solution for the generation of window effects in a scanner environment.

The use of a mask for the storage of window effects requires large amounts of memory to represent the mask, and the requirement for programming this memory results in a system throughput delay while this is accomplished.

Rectangular window generators offer a reduction in the amount of hardware needed to control the window effects, however, they lack flexibility in that only rectangular windows, in limited numbers, are available. This disclosure describes means to overcome the short falls of each approach through the use of a Window Effect Processor to generate the required effects. This processor will make use of two-dimensional compression of the window effect mask to reduce the redundancy found in the mask approach. The Window Effect Processor is envisioned to be a stack oriented processor operating on a sequence of tasks aligned into blocks. Each block of tasks, illustrated in the Figure 1, is further broken into Fast Scan tas...