Browse Prior Art Database

INPUT OF CONTROL INFORMATION TO AN ELECTRONIC IMAGE SCANNER THROUGH THE IMAGING APPARATUS

IP.com Disclosure Number: IPCOM000026172D
Original Publication Date: 1990-Aug-31
Included in the Prior Art Database: 2004-Apr-05
Document File: 8 page(s) / 296K

Publishing Venue

Xerox Disclosure Journal

Abstract

In conjunction with an image scanning device, various image processing functions are available for altering the appearance of the document image acquired at the scanning array. Two particularly common functions are screening and thresholding. Data is initially derived in an analog form, and then converted to a digital value. Then, thresholding functions typically compare the image data with a uniform level across an image, to provide a binary output from the digital image data. Varying the threshold level varies the contrast of the image. Screening is a similar function, used to simulate gray levels within an image. Over a unit area of several pixels in the image, a series of threshold levels are applied to the image data so that a binary output is still produced, but varying over the unit area, depending on the density of the level of grey in the original image. Different screens apply different patterns of threshold levels to achieve different effects. It is highly desirable to provide a plurality of threshold levels and screens in a scanning device. The application of screens and thresholds to image data, as well as the types of screens is well known.

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Page 1 of 8

XEROX DISCLOSURE JOURNAL

INPUT OF CONTROL Proposed Classification INFORMATION TO AN U.S. C1.382/022 ELECTRONIC IMAGE SCANNER
THROUGH THE IMAGING
APPARATUS
Robert
P. Herloski

Int. C1. G06k 9/48

104 102

FIG. I

XEROX DISCLOSURE JOURNAL - Vol. 15, No. 4 July/August 1990 285

[This page contains 1 picture or other non-text object]

Page 2 of 8

INPUT OF CONTROL INFORMATION TO AN ELECTRONIC IMAGE SCANNER THROUGH THE IMAGING APPARATUS(Cont'd)

FIG. 2A

286 XEROX DISCLOSURE JOURNAL - Vol. 15, No. 4 July/August 1990

[This page contains 1 picture or other non-text object]

Page 3 of 8

INPUT OF CONTROL INFORMATION TO AN ELECTRONIC IMAGE SCANNER THROUGH THE IMAGING APPARATUS(Cont'd)

FIG. 2B

XEROX DISCLOSURE JOURNAL - Vol. 15, No. 4 July/August 1990 287

[This page contains 1 picture or other non-text object]

Page 4 of 8

INPUT OF' CONTROL INFORMATION TO AN ELECTRONIC IMAGE SCANNER THROUGH THE IMAGING APPARATUS(Cont'd)

200 208 210

                                                          FURTHER IMAGE DATA DIA THRESHOLD ' SCREEN + PROCESSING

CONVERTER + OUTPUT

I I

I

PIXEL CLOCK LATCH FOR COUNTED

                                   VALUE DECODE, d COUNTER COUNTED SCANLINE CLOC VALUE

202 24

\ b 206

FIG. 3

288 XEROX DISCLOSURE JOURNAL - Vol. 15, No. 4 July/August 1990

[This page contains 1 picture or other non-text object]

Page 5 of 8

INPUT OF CONTROL INFORMATION TO AN ELECTRONIC IMAGE SCANNER THROUGH THE IMAGING APPARATUS(C0nt'd)

In conjunction with an image scanning device, various image processing functions are available for altering the appearance of the document image acquired at the scanning array. Two particularly common functions are screening and thresholding. Data is initially derived in an analog form, and then converted to a digital value. Then, thresholding functions typically compare the image data with a uniform level across an image, to provide a binary output from the digital image data. Varying the threshold level varies the contrast of the image. Screening is a similar function, used to simulate gray levels within an image. Over a unit area of several pixels in the image, a series of threshold levels are applied to the image data so that a binary output is still produced, but varying over the unit area, depending on the density of the level of grey in the original image. Different screens apply different patterns of threshold levels to achieve different effects. It is highly desirable to provide a plurality of threshold levels and screens in a scanning device. The application of screens and thresholds to image data, as well as the types of screens is well known.

To instruct the image processing system which screen or threshold function to use, a simple slide switch, and as best seen seen in Figure 1 and the worm's eye view of Figure 2, a sliding indicator member 100 is provided in the upper surface 12 of enclosure 11. The sliding indicator 100 is a disk-shaped member mounted for rotational movement on the upper surface 12 of the enclosure 11. On the disk upper surface, slide handle member 102 is available exterior to enclosure...