US5055942A — Photographic image reproduction device using digi…

Claim 1

Independent Claim 176 words

An image reproducing system, comprising: a) a scanning means for reading input image data corresponding to the image to be reproduced; b) a screening device comprising: memory means for storing the input image data as gray scale values for sequences of pluralities of input points, and for storing a plurality of binary output signals which direct a marking device to mark and not mark indicia on a medium; means for generating signals allocating the marking and not marking of the indicia on the medium based on a value of a current input point in a sequence of input points, a previous output signal corresponding to a previous input point in the sequence and an error representing a difference between the previous input point and the corresponding output signals scaled relative to a maximum gray scale, the error influencing output signals for subsequent input points in the sequence; and c) a marking device to receive the output signals from the screening device, whereby the marking device marks variable size dots comprising indicia corresponding to said output signals.

Claim 2

Dependent Claim 176 words

An image reproducing system, comprising: a) a scanning means for reading input image data corresponding to the image to be reproduced; b) a screening device comprising: memory means for storing the input image data as gray scale values for sequences of pluralities of input points, and for storing a plurality of binary output signals which direct a marking device to mark and not mark indicia on a medium; means for generating signals allocating the marking and not marking of the indicia on the medium based on a value of a current input point in a sequence of input points, a previous output signal corresponding to a previous input point in the sequence and an error representing a difference between the previous input point and the corresponding output signals scaled relative to a maximum gray scale, the error influencing output signals for subsequent input points in the sequence; and c) a marking device to receive the output signals from the screening device, whereby the marking device marks variable size dots comprising indicia corresponding to said output signals.

Claim 3

Dependent Claim 33 words

The apparatus recited in claim 1 wherein the scanning device scans a plurality of lines corresponding to the image and the sequence corresponds to a plurality of points on at least one line.

Claim 4

Independent Claim 236 words

A method for reproducing a photographic image comprising the steps of: scanning a plurality of input points of an original image for reading input image data corresponding to the input pixels of the image to be reproduced; for a present input pixel, adding an error value previously generated for a first pixel adjacent in a first scanning direction to the present input pixel with an error value generated for a second pixel adjacent to the present input pixel in a second scanning direction orthogonal to the first scanning direction and creating a first result; dividing said first result by two and creating a second result; adding an input data to said second result creating a third result; adding an output value previously generated for the first pixel with an output value previously generated for the second pixel to create a fourth result; multiplying said fourth result by a hysteresis constant to create a fifth result; adding said fifth result to said third result to create a sixth result; storing a seventh result of 1 if said sixth result is not less than zero and if said sixth result is less than zero storing a seventh result of 0; multiplying said seventh result by a constant creating an eighth result; subtracting said eighth result from said third result to create a present error value and marking indicia on an output medium in accordance with said seventh result.

Claim 5

Independent Claim 236 words

A method for reproducing a photographic image comprising the steps of: scanning a plurality of input points of an original image for reading input image data corresponding to the input pixels of the image to be reproduced; for a present input pixel, adding an error value previously generated for a first pixel adjacent in a first scanning direction to the present input pixel with an error value generated for a second pixel adjacent to the present input pixel in a second scanning direction orthogonal to the first scanning direction and creating a first result; dividing said first result by two and creating a second result; adding an input data to said second result creating a third result; adding an output value previously generated for the first pixel with an output value previously generated for the second pixel to create a fourth result; multiplying said fourth result by a hysteresis constant to create a fifth result; adding said fifth result to said third result to create a sixth result; storing a seventh result of 1 if said sixth result is not less than zero and if said sixth result is less than zero storing a seventh result of 0; multiplying said seventh result by a constant creating an eighth result; subtracting said eighth result from said third result to create a present error value and marking indicia on an output medium in accordance with said seventh result.

Claim 6

Dependent Claim 113 words

A photographic image reproducing system comprising: a scanning device receiving an input array i(x,y) corresponding to an original image to be reproduced, wherein x and y represent scanning directions; a marking device receiving output signals o(x,y) from a screening device for marking indicia on an output medium in accordance with said output signals o(x,y); the screening device using said input array i(x,y) in a recurrence relation calculation means for calculating a recurrence relation given by the following equations: ##EQU4## wherein fs is a maximum allowable value of members of said array i(x,y), and h is a hysteresis constant, E (X, Y) defines an error function, and E'(X, Y) defines a secondary error function.

Claim 7

Dependent Claim 113 words

A photographic image reproducing system comprising: a scanning device receiving an input array i(x,y) corresponding to an original image to be reproduced, wherein x and y represent scanning directions; a marking device receiving output signals o(x,y) from a screening device for marking indicia on an output medium in accordance with said output signals o(x,y); the screening device using said input array i(x,y) in a recurrence relation calculation means for calculating a recurrence relation given by the following equations: ##EQU4## wherein fs is a maximum allowable value of members of said array i(x,y), and h is a hysteresis constant, E (X, Y) defines an error function, and E'(X, Y) defines a secondary error function.

Claim 8

Dependent Claim 19 words

A photographic image reproducing system as recited in claim 4 wherein: e(x,-1)=0; e(-1, y)=0; e(width,y)=0; o(x,-1)=0; o(-1,y)=0; and o(width,y)=0.

Claim 9

Independent Claim 117 words

A method of producing a halftone image comprising the steps of: scanning a plurality of input points of an original image and generating a numerical value representing a shade of gray for each input point scanned; outputting a screened image having a plurality of dots, each dot of said plurality of dots being one of black or white, the size of each plurality of dots being determined from a recursive relationship between a value of a current input point, a previous output, and an error representing a difference between a value of a previous input point and the previous output; and transmitting signals representing the screened image to a marking device for marking on an output medium.

Claim 10

Independent Claim 117 words

A method of producing a halftone image comprising the steps of: scanning a plurality of input points of an original image and generating a numerical value representing a shade of gray for each input point scanned; outputting a screened image having a plurality of dots, each dot of said plurality of dots being one of black or white, the size of each plurality of dots being determined from a recursive relationship between a value of a current input point, a previous output, and an error representing a difference between a value of a previous input point and the previous output; and transmitting signals representing the screened image to a marking device for marking on an output medium.

Claim 11

Dependent Claim 24 words

The method recited in claim 6 wherein the recursive relationship employs a hysteresis constant, the hysteresis constant determining the coarseness of the screened image.

Claim 12

Dependent Claim 19 words

The method recited in claim 7 wherein the hysteresis constant defines an allowable excursion of the error around zero.

Claim 13

Dependent Claim 14 words

The method recited in claim 6 wherein the scanning is performed in two dimensions.

Claim 14

Dependent Claim 14 words

The method recited in claim 6 wherein the error is allocated in two dimensions.

Claim 15

Dependent Claim 18 words

The method recited in claim 10 wherein the error is allocated equally in each of the two dimensions.

Claim 16

Dependent Claim 98 words

The method recited in claim 6 wherein the recursive relationship is defined as: ##EQU5## where x refers to pixels in a scan line, y refers to the scan lines, i(x, y) and o(x, y) are the input and output arrays, respectively, fs is the full scale input value, typically 255 in the case of an eight bit array, and h is an hysteresis constant typically of value 0.5 times the value of fs and where larger values of h result in a coarser screen, E (X, Y) defines an error function, E' (X,Y) defines a secondary error function.

Claim 17

Dependent Claim 29 words

The method in claim 12 wherein fs is a value representing a maximum gray shade and h is a product of fs and a number not less than zero.

Claim 18

Dependent Claim 23 words

The method recited in claim 6 wherein the black dots and white dots are produced by marking and not marking the medium, respectively.

Claim 19

Independent Claim 120 words

An apparatus for producing a halftone image comprising: means for scanning a plurality of input points of an original image and generating a numerical value representing a shade of gray for each input point scanned; means for outputting a screened image having a plurality of dots, each dot of said plurality of dots being one of black or white, the size of each plurality of dots being determined from a recursive relationship between a value of a current input point, a previous output, and an error representing a difference between a value of a previous input point and the previous output; and means for transmitting signals representing the screened image to a marking device for marking on an output medium.

Claim 20

Independent Claim 120 words

An apparatus for producing a halftone image comprising: means for scanning a plurality of input points of an original image and generating a numerical value representing a shade of gray for each input point scanned; means for outputting a screened image having a plurality of dots, each dot of said plurality of dots being one of black or white, the size of each plurality of dots being determined from a recursive relationship between a value of a current input point, a previous output, and an error representing a difference between a value of a previous input point and the previous output; and means for transmitting signals representing the screened image to a marking device for marking on an output medium.

Claim 21

Dependent Claim 24 words

The apparatus recited in claim 15 wherein the recursive relationship employs a hysteresis constant, the hysteresis constant determining the coarseness of the screened image.

Claim 22

Dependent Claim 19 words

The apparatus recited in claim 16 wherein the hysteresis constant defines an allowable excursion of the error around zero.

Claim 23

Dependent Claim 14 words

The apparatus recited in claim 15 wherein the scanning is performed in two dimensions.

Claim 24

Dependent Claim 14 words

The apparatus recited in claim 15 wherein the error is allocated in two dimensions.

Claim 25

Dependent Claim 18 words

The apparatus recited in claim 19 wherein the error is allocated equally in each of the two dimensions.

Claim 26

Dependent Claim 97 words

The apparatus recited in claim 15 wherein the recursive relationship is defined as: ##EQU6## where x refers to pixels in a scan line, y refers to the scan lines, i(x, y) and o(x, y) are the input and output arrays, respectively, fs is the full scale input value, typically 255 in the case of an eight bit array, and h is a hysteresis constant typically of value 0.5 times the value of fs and where larger values of h, result in a coarser screen, E (X,Y) defines an error function, E" (X,Y) defines a secondary error function.

Claim 27

Dependent Claim 30 words

The apparatus recited in claim 21 wherein fs is a value representing a maximum gray shade and h is a product of fs and a number not less than zero.

Claim 28

Dependent Claim 22 words

The apparatus recited in claim 15 wherein the black and white dots correspond to marking and not marking the output medium, respectively.

Claim 29

Independent Claim 256 words

An apparatus for reproducing a photographic image comprising: means for scanning a plurality of input points of an original image for reading input image data corresponding to the input pixels of the image to be reproduced; means for isolating a present input pixel and adding an error value previously generated for a first pixel adjacent in a first scanning direction to the present input pixel with an error value generated for a second pixel adjacent to the present input pixel in a second scanning direction orthogonal to the first scanning direction and creating a first result; means for dividing said first result by two and creating a second result; means for adding an input data to said second result creating a third result; means for adding an output value previously generated for the first pixel with an output value previously generated for the second pixel to create a fourth result; means for multipliying said fourth result by a hysteresis constant to create a fifth result; means for adding said fifth result to said third result to create a sixth result; means for storing a seventh result of 1 if said sixth result is not less than zero and if said sixth result is less than zero storing a seventh result of 0; means for multipliying said seventh result by a constant creating an eighth result; means for subtracting said eighth result from said third result to create a present error value and means for marking indicia on an output medium in accordance with said seventh result.

Claim 30

Independent Claim 256 words

An apparatus for reproducing a photographic image comprising: means for scanning a plurality of input points of an original image for reading input image data corresponding to the input pixels of the image to be reproduced; means for isolating a present input pixel and adding an error value previously generated for a first pixel adjacent in a first scanning direction to the present input pixel with an error value generated for a second pixel adjacent to the present input pixel in a second scanning direction orthogonal to the first scanning direction and creating a first result; means for dividing said first result by two and creating a second result; means for adding an input data to said second result creating a third result; means for adding an output value previously generated for the first pixel with an output value previously generated for the second pixel to create a fourth result; means for multipliying said fourth result by a hysteresis constant to create a fifth result; means for adding said fifth result to said third result to create a sixth result; means for storing a seventh result of 1 if said sixth result is not less than zero and if said sixth result is less than zero storing a seventh result of 0; means for multipliying said seventh result by a constant creating an eighth result; means for subtracting said eighth result from said third result to create a present error value and means for marking indicia on an output medium in accordance with said seventh result.

Claim 31

Dependent Claim 185 words

An image reproducing system for generating on an input medium an image corresponding to an original image, the system comprising: a) a scanning means for reading input data of the original image to be reproduced, the scanning means generating signals representing gray scale values corresponding to each pixel of the original; b) a screening device comprising: memory means for storing the image data corresponding to each pixel and a plurality of output signals which direct a marking device to mark one of black or white indicia on the output medium for each output signal, each output signal corresponding to a pixel on the output medium; means for generating signals allocating the black or white indicia on the output medium based on the gray scale value of a current gray scale scale signal, a previous output signal and an error signal representing a difference between the current gray scale signals and at least one previously generated output signal; c) a marking device to receive the output signals from the screening device, the marking device thereby generating variable size dots comprising indicia corresponding to the output signals.

Claim 32

Dependent Claim 185 words

An image reproducing system for generating on an input medium an image corresponding to an original image, the system comprising: a) a scanning means for reading input data of the original image to be reproduced, the scanning means generating signals representing gray scale values corresponding to each pixel of the original; b) a screening device comprising: memory means for storing the image data corresponding to each pixel and a plurality of output signals which direct a marking device to mark one of black or white indicia on the output medium for each output signal, each output signal corresponding to a pixel on the output medium; means for generating signals allocating the black or white indicia on the output medium based on the gray scale value of a current gray scale scale signal, a previous output signal and an error signal representing a difference between the current gray scale signals and at least one previously generated output signal; c) a marking device to receive the output signals from the screening device, the marking device thereby generating variable size dots comprising indicia corresponding to the output signals.

Claim 33

Dependent Claim 23 words

The apparatus recited in claim 25 wherein the black and white indicia correspond to marking and not marking of the output medium, respectively.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-10-07	1995-04-08	1995-10-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-10-07	1999-04-08	1999-10-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-10-07	2003-04-08	2003-10-08	$7700.00	Window Closed / Lapsed

Photographic image reproduction device using digital halftoning to screen images allowing adjustable coarseness

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