GB2151106A - Picture scanning and reproducing method - Google Patents

Abstract

An original document with plural picture areas to be reproduced in different processing modes is photoelectrically scanned (101) and displayed on a monitor CRT. The entire area of the original is divided by lines parallel to the axes into a plurality of areas by keyboard signals. X-address data and Y-address data, which designate the lines, are stored in a register. Codes representing the areas and control data designating the processing modes are stored in a memory. The X-address data and Y-address data are compared (112, 113, 116, 117) with the scanning address to provide coded data identifying the divided areas as each is entered. From the coded data, control data designating the corresponding processing modes are obtained and stored in the memory. The original picture is then reproduced in the respective processing modes, on the basis of the control data. Change of scale may be included in the reproduction. <IMAGE>

Description

SPECIFICATION Picture scanning and reproducing method This invention relates to a picture scanning and reproducing method which when one desires to record at a desired area a picture reproduced as a halftone picturefrom an original and at another desired area another picture reproduced from the original without converting same into any halftone picture in a picture scanning and reproducing apparatus capable of reproducing and recording halftone pictures directly by an electronic control technique, for example, in a plane scanner, cylindrical scanner or the like, permits recordation of the reproduced pic tu resin desired processing modes depending respec tively on the areas at which the reproduced picture are to be recorded.

In a picture scanning and reproducing apparatus adapted to reproduce halftone pictures directly by an electronic control technique, for example, in a usual colorscannerequipped with a dot generator, halftone pictures have conventionally been reproduced by applying a halftone process to the entire area of each original.

In orderto meetthe recent trend toward the man powersaving in the fabrication of printing plates, itis however desired to conduct the layout on each original so thatthe color correction, halftone proces- sing, magnification change, and various other picture processings required for the fabrication of printing plates may be completed in a single operation of reproduction.

As shown byway of example in Fig. 1, an original may in some instances contain, in a mixed pattern, picture areas P having a middle tone and requiring a halftone process and character areas Q bearing binary-coded pictures such as characters, line drawings and the like. When such an original OR is processed by a usual scanner equipped with a conventional dot generator, the character areas Qare also subjected to the halftone process and as a result, characters andthe like contained in the character areas Q are recorded by halftone dots with a picture resolution preset in the dot generator. This has led to a drawbackthatthe edges of picture lines such as characters are reproduced in zig-zag patterns.

Japanese PatentApplication Nos. 144742/1983 and 171622/1983,which have both been assigned commonlytothe assignee ofthe present application, disclose to determine a scanning-starting point and scanning-stopping point on an original wrapped on an original cylinder of a drum-shaped scanner by shifting the scanning head and/or cylinder, for example, through their manual control to bring the optical pick-up axis and image pick-up point into registration with the above-mentioned points and then by performing the setting of picture patterns, line drawings and/orthe like with respect to a rectangular area determined by the two points. These methods are however not suitable unless the optical pick-up axis and image pick-up point are moved onto the original.

It has thus been proposed in Japanese Patent Application No. 100236/1983,which has also been assigned to the present assignee, to scan separately and parallelly binary-coded patterns such as characters, marks and the like in a photodetecting fashion with finely-divided groups of photodetectors and to make use ofthe ability of a dot generator to form individual halftone dots as a combination of a number offine dots, thereby to record the characters, marks and the like with a resolution finerthan the picture resolution, such as a resolution equivalent to a single piece ofthe fine dot, twice the resolution, fourtimes the resolution orthe like.

In the method disclosed in the above Japanese Patent Application No. 100236/1983, there are provided, for example, continuous tone (halftone process) photodetectors and line drawing photodetectors, both separately from the area of each original, in the optical path of incoming light. By designating halftone areas and line drawing areas in advance, an output is selectively obtained from either one group of the continuous tone photodetectors and the line drawing photodetectors for each area designated during the scanning ofthe original, whereby outputting and recording halftone dots or line drawing.

Furthermore, picture signals obtained as light by scanning the original with a resolution corresponding to line drawings are compared with a given value to convert them into line drawing signals, whereby recording iine drawings. When compared with halftone dot standard signals, halftone picture signals are obtained.The halftone picture signals are then subjected to a halftone process so that halftone dots are recorded. This will be described infurtherdetail in the description of one embodiment ofthis invention.

The method disclosed in Japanese Patent Application No.203418/1983, which has also been assigned to the present assignee, requires to provide a number of photodetectorsfor line drawings so that a plurality of areas may be processed atthe same time. Accordingly, it requires many photodetectors and a complex processing circuit In the above-mentioned method of Japanese Patent Application No.203418/1983, all areas otherthan character areas are assumed to be picture areas. As a result, each character area or picture area is output as is, or is output as a solid white or black area.

An object of this invention isto provide a picture scanning and reproducing method in which a line drawing is scanned at a fineness required forthe line drawing, resulting optical signals are received, and the scan-recording isthen effected.

In one aspect of this invention, there is provided a method for scanning and reproducing a picture, said method including controlling the recording-side scanning means in accordance with picture signals obtained by photoelectrically scanning an original containing plural kinds of picture areas which should respectively be recorded in different processing modes and then recording the resulting picture reproduced from the original, which method comprises: dividing the entire area ofthe original by a plurality of lines, each of which extends in the direction of X-axis orY-axis, in different processing modes into a pluralityofareas in accordancewith plural kinds of picture areas to be recorded; storing X-address data andY-address data,which designate the plurality of lines respectively, in a registerorthe like; and storing codes representing respectivelythethus-divided areas and control data designating processing modes to be adopted to record the thus-divided areas in a memory orthe like; and comparing the X-address data and Y-address data, which have been stored in the registerorthe like, with address signals obtained upon scanning the original and corresponding to scanning spots so that coded data representing respectively the divided areas are obtained; obtaining, from the coded data, control data designating the processing modes stored in the memon/orthe like; and recording the reproduced picture in the processing modes, which are required for the respective divided areas, on the basis ofthe control data.

The above method permits use of a simple processing circuit. As will be described in detail in the description of one embodimentofthis invention, it is the last processing circuitthat selectively determines as which one of halftone picture, line picture and halftone pattern each area is to be reproduced.

Therefore, an original containing both halftone pictures and line drawings in a mixed pattern may be reproduced by a simple structure while reproducing the pictures and line drawings simultaneously.

Furthermore, a desired area of an original may be reproduced as a halftone pattern or as a solid white or black area. The opaquing of an unnecessary area may be carried out simultaneously.

The above and other objects, features and advantageous ofthe present invention will become appa rentfromthefollowing description and the appended claims, taken in conjunction with the accompanying drawings.

In the accompanying drawings: Fig. is a drawing showing an original, which contains both picture areas and character areas in a mixed pattern, and an original-setting device; Fig. 2 is an original and original-setting device, both usable in one embodiment ofthe method of this invention; Fig. 3 illustrates one example of the display of areas of a reproduced pattern obtained in accordance with the method of this invention; Fig. 4 illustrates the overall structure ofthe present invention; Fig. 5 is a flow chart of an area-setting method according to this invention; and Fig. 6 is a block diagram showing one example of a picture scanning, reproducing and recording apparatus useful in actually practicing the method of this invention.

One embodiment ofthis invention will now be described with reference to the accompanying drawings.

According to the present invention, a plurality of horizontal and vertical lines K are displayed, for the entire area of an original OR placed on an originalsetting deviceT, on a cathode-ray tube monitor by inputting through a key board address values which have been obtained in accordance with a scale S displayed on ths original-setting device while watch ingthe original. Resulting rectangularareas,which are surrounded by the lines K, are then classified into different modes (processing modes), namely, 1...

halftone picture, 2... line drawing and 3. . . halftone pattern.

The dot area percentages of halftone patterns may range from 0% to 100%. Solid white (dot area percentage: 0%) is numerically identified by 4while solid black (dot area percentage: 100%) is numerically represented by 5.

Fig. 2 illustrates one example of the layout ofthe original on the original-setting deviceT, which original isto be reproduced. Fig. 3 shows the areas of a picture reproduced from the original OR and displayed in accordancewith one embodiment ofthis invention.

In Figs. 2 and 3, Y indicates addresses corresponding to scanning spots along the main scanning direction. The arrow indicates the scanning direction and the advancing direction ofthe addresses Y.

Addresses corresponding to scanning spots along the sub-scanning direction are indicated by X. The arrow indicates the scanning direction and the advancing direction ofthe addresses X.

Y1, Y2, X1 and X2 represent specific address values on the addresses X, Y.

In the original OR, halftone picture areas (P) (first areas), line drawing areas Q (second areas) and the remaining areas R (third areas) are divided in advance into nine areas A-I by the address values Y1,Y2 and address values X1, X2.

The third areas R record solid white, solid black or halftone patterns.

Fig. 3 illustrates the areas of a reproduced picture CP obtained by processing the above-mentioned original OR in accordance with the method of this invention.

Thefinished dimensions may be suitably enlarged (or reduced).

The nine areas A-I ofthe original OR, which have in advance been divided, are reproduced corresponding to the areas A-l ofthe original OR, thereby obtaining the reproduced picture CP which are divided in nine areas A-l as will be described herein.

Each ofthe picture areas P is subjected to a halftone process and is reproduced and recorded as a halftone picture area P'. On the other hand, each of the line drawing areas Q is reproduced and recorded as is, namely, as a line drawing area Q'.

Corresponding to each ofthethird areas R, a halftone pattern having the same dot area percentage, which may rangefrom 0% to 100%, is recorded all overitsarea.

Fig.4 shows one example of a system suitable for use in the practice ofthe present invention.

Numerals 1 and 2 designate a CPU (central processing unit) and a RAM (random-access memory) respectively. Information which has been numerically set by a key board is operated by the CPU, stored in the RAM and then displayed on CRT(cathode-raytube) 9.

Designated at numeral 3 isa RAM (random access memory) which is used to temporarily store operation results and data ofthe CPU 1. Numeral 4 indicates a ROM (non-volatile memory), in which a basic monitoring program and characterdata are stored.

Numerals 5,7 indicate l/O interfaces, which are adapted to input information from the outside and also to output information to the outside. Designated at numeral 6 is a key board, which is used to input various data and information. Numeral 8 indicates a register memory which transmits operation results from the CPU 1 to a memory 10. At numeral 9, there is shown a CRT (cathode-ray tube monitor) which displays for example in such a manner as illustrated in Fig. 3.

An operator performs the setting of areas by inputting the dividing coordinate values X1, X2, Y1, Y2 in both horizontal and vertical directions through the key board in accordance with the individual modes of the original OR shown in Fig. 2, while watching the display ofthe monitor 9 illustrated in Fig. 3.

Fig. 5 is a flow chart ofthe area setting shown in Fig.

4.

The subroutine of Fig. 5 pertains to a change to the setting of areas, namely, shows one example of setting of lines K. These lines K are set by reading address values X1, X2, Y1, Y2from the scale Son the original-setting deviceT. Based on these data, an operation is performed in the CPU.

On the basis of results of the operation, the contents ofthe RAM 2 are changed. The contents of the RAM 2 are displayed on the CRT9 as illustrated in Fig. 3.

On the other hand, various data operated by the CPU 1 and address values are both stored in the register memory 8.

Fig. 6 shows one embodimentfor recording pictures of various modes (processing modes) on their corresponding areas in accordance with values set by the registermemory8shown in Fig. 4.

Values obtained as a result of an operation illustrated in Fig. 4 are then set in a plain halftone density presetter 106, a threshold presetter 107, address presetters 114,115,118,119, and an output mode selection memory 120, all of which are shown in Fig. 6.

A picture input unit 101 scansthe original OR photoelectrically. Here, the original OR is normally scanned with a scanning line pitch of a resolution sufficientlyfinerthan the dot pitch of a halftone required forthe halftone picture P' of the reproduced picture CP. The dot pitch corresponds to the screen ruling.

A picture signal g1 obtained as a result of the photoelectrical scanning ofthe original OR by the picture input unit 101 is then converted to a digital picture signal d1 by an A/D (analog/digital) converter 102.

The resultant digital signal d1 is then fed to a picture processing unit 103 which includes magnificationchanging means and the like, where the digital signal d1 is subjected to a picture signal processing required to convert the pattern in the picture area P into a desired reproduced picture suitable for use in the fabrication of a printing plate, such as tone correction, sharpness emphasis, etc.

Any known means may be employed as the magnification-changing means. For example, the magnification-changing means removes at a constant picture element interval sampled picture data so as to reduce the size of the resulting reproduced picture, or overlaps at a constant picture element interval picture data so as to obtain a reproduced picture on an enlarged scale.

The picture processing unit 103 outputs a processed digital picture signal d2, which is then fed to one of the data input terminals of a first data selector 104, for example, to a data inputterminal 4a The digital picture signals da, d2 are signals of 8 bits for example. The first data selector 104 and a second data selector 105, which will be described herein, are both for 8-bit signals. Furthermore, various picturepertaining data which will next be described are also of8 bits.

To the other data input terminal of the first data selector 104, namely, to a data input terminal 4b,there is input a constant-density data e1 which has been output from the plain halftone density presetter 106 composed of a register circuit.

To one of data input terminals ofthe second data selector 105, namely,toa data inputterminal 5a,a threshold data e2 which has been outputfrom a threshold presetter 107 adapted to convert digital picture signals into binary-coded picture signals.

The threshold presetter 107 is a register circuit and the threshold data e2 stored in thethreshold presetter 107 may generally have a value one half the density width ofthe processed digital picture signal d2. Where the character density does not reach the maximum density value, it is desirable to set the threshold data e2 at a density value intermediate between the background density ofthe character area and the density of its characters.

Totheotherdata inputterminal Sbofthesecond data selector 105, there is input unfocused halftone data e3which has been output from a halftone pattern memory 108 and simulates a contactscreen.

In the halftone pattern memory 108, addresses are designated by address signals A, Ax of an address counter 109 adapted to determined addresses Y', X' corresponding to scanning spots when the picture input unit 101 scans overtheoriginal OR.

The address counter 109 is not limited to those designating the entire address ranges of the addresses X, Y of the original OR. The address counter 109 is constructed of a suitable m x n binary counter which corresponds to the repetition cycle ofthe halftone pattern.

The address counter 109 feeds a chain of numerous pulses, which are generated at a constant pulse interval per every stroke of the main scanning ofthe picture input unit 101, as address signals Ay along the address Y ofthe main scanning direction in accordance with clock pulses 1)y communicated at a pulse interval equivalent to the sampling pitch forthe chain of picture elements lining up on the main scanning line.

The address counter 109 causes the address signals Ax along the address X of the sub-scanning direction to advance in accordance with clock pulses qzx each generated per every sub-scanning line of the picture input unit 101.

The unfocused halftone dot data e3 corresponding respectively to the unfocused halftone dots on the contact screen, which has a halftone structure with a dot pitch required for the halftone picture P, is output from the halftone pattern memory 108 which is designated in address by the addresses Ay, Ax.

On the other hand, the addresses X, Y representing spots on the entire area scanned by the picture input unit 101 are counted as address signals Ay, Ax output respectivelyfrom a V-counter 110 and X-counter 111, bycounting theclockpulses çyand clock pulses x with theY-counter and X-counter respectively.

The address signals Ay are input respectively to one ofthe inputterminals of each offirst and second comparators 112,113, namely, to the inputterminals 12a, 1 3b, while address data Ay1, Ay2 output from first and second address presetters 114, 115, which are adapted to divide each area along the address V, are fed to the other inputterminals 12a,13a ofthe comparators 112, 113.

The address signals Ay are input respectivelyto one ofthe inputterminals of each offirst and second comparators 116,117, namely, to the input terminals 1 6b, 1 7b, while address data Ax,, AX2 output from first and second address presetters 118, 119, which are adapted to divide each area along the address X, are fed to the other inputterminals 16aha of the comparators 116,117.

Each ofthe address presetters 114,115 and 118, 119 is composed of a register circuit, latch circuit orthe like. In these address presetters 114,115,118,119, there have already been preset, as described with reference to Fig. 4, address data Ay1, Ay2, Axi, AX2 which are either equivalent or equal to their corresponding address values V1, V2, X1, X2 on the line dividing the picture area P' and the character area Q' from each other in the reproduced picture CP depicted in Fig. 2.

One-bit data yl, Y2 Xi, X2 output respectively from the comparators 112,113,116,117 are delivered asa 4-bit area-designating address signal e4 of the bit parallel type to the address terminal of an output mode selection memory 120, whereby designating the address ofthe output mode section memory 120.

In the output mode selection memory 120, there have already been recorded, as shown in Fig. 4, output mode control data eS corresponding to output modes required forthe pre-divided areas P, O, Ron the original OR in such a waythatthey correspond to the area-designating address signals e4.

When the original OR is scanned, the area-designating address signals e4 are output in each ofthe areas A-l, for example, with such a bit pattern [Y2 y1,x2,x1] as indicated by 4 bits in each of the areas shown in Fig.

2.

As described with reference to Fig. 4, the output mode control data e5 are recorded in advance as such coded 2-bit data [S2, S] as illustrated in each ofthe areas A-l in Fig. 3, corresponding to the bit pattern of the above-mentioned area-designating address signal e4, in the output mode selection memory 120.

The lower bit S, ofthe 2-bit output mode control data e5 is inputto a selection terminal 4cofthefirst data selector 4while the upper bit S2 is delivered to a selection terminal Scofthe second data selector 105.

The data selector 104 outputs the picture signal d2 when the input Si to the selection terminal 4e is logic [01 butthe constant density data e1 when the input Si is logic [1], both to the outputterminal 4d. The data e6 output from the data selector 104 is delivered to one of the inputterminals of the comparator21, namely, to a inputterminal 21 a.

The data selector 105 outputs the threshold data e2 ofthe line drawing picture when the input S2to the selection terminal Scis logic [0] but the unfocused halftone dot data e3 when the input S2 is logic [1], both totheoutputterminal5d.Thedata d6 outputfrom the data selector 104 is delivered to one ofthe input terminals ofthe comparator 21, namely, to a input terminal 21 a. The output data 4 ofthe data selector 105 is supplied to the other input terminal 21 b of the comparatorl21.

When the first area is scanned, the coded data ofthe output mode control data e5 is [10]. The comparator 121 compares the picture signal d2 obtained as a result of scanning ofthe halftone picture area Pwiththe unfocused halftone dot data e3, slices the unfocused halftone dot data e3 atthe level ofthe picture signal d2, and as a result, output a picture signal e8from an output terminal 21 cforthe recordation of a halftone picture. The picture signal e8 reproduces and records the halftone picture P' by way of a picture recorder 122.

When the second area is scanned, the coded data of the output mode control data e5 is [00]. The comparator 121 slices the picture signal d2, which corresponds to the line drawing area Q, by the threshold data e2, thereby outputting the picture signal e8forthe recordation of a line drawing picture and hence reproducing and recording the line drawing picture Q which has not been subjected to the halftone process and has high fidelity.

When the third area is scanned, the coded data of the output mode control data e5 is [11]. The comparator 121 comparesthe constant density data chosen for the third area R with the unfocused halftone dot data 4 and outputs a picturesignalfortherecordationofa halftone picture having a uniform dot area percentage corresponding tothe density data ea, wherebyto record the halftone pattern R'.

In the above embodiment, the original OR was divided into the nine areas A-l. When dividing the original OR into more areas, it is necessaryto provide a suitable numberofadditional devices which are respectively similarto the area-dividing address presetters 114,115,118,119 and comparators 112, 113,116,117 and correspondingly to expand the address range of the output mode control memory 121. Owing to the provision of such additional devices, finely-divided areas can be obtained with ease.

Furthermore, it is also possible to record readily a halftone pattern having a desired dot area percentage in the third area R.

In the above embodiment,2-bit output mode control data eS were used. When it is desired to perform another processing mode in combination with the halftone processing, for example, to process the picture area P and character area 0 under different conditions such as different contour-emphasizing conditions inthe picture processing circuit3,the upper bit S2 Of the control data e5 may be used commonly with the selection of the data selector 5 so as to have the upper bit S2 represent such different conditions. Alternatively, it is readily possible to increase the bit number of the control data e5to 3 bits so thatthethus-increased additional bit is used to designate the above-mentioned processing.

The plain halftone density value q and threshold e2 may also be recorded in the output mode selection memory 120, as output control data for the memory 120. By doing so, halftone patterns having different density levels from one third area to anotherthird area may be recorded by means ofthe threshold e2. When the output mode control data e5 is set as [0, 1], reproduced areas may be rendered solid white or solid black depending on the relationship in magnitude between the data e1 and the data e2.

In addition, it is also possible to prevent stain on the original from appearing on its reproduced picture by adjusting the setting level ofthethreshold e2.

In the above-described embodiment, three types of processing modes were employed. If two types of processing modes are sufficient, it is only necessary to input one of the two types of processing modes because the other processing mode can always be performed unlesstheformer processing mode is input.

As mentioned above, the present invention can also employvarious coordinate setting methods other than that used in the above embodiment, for example, by carrying outthe input of various data through a digitizer, a digitizer making use of a linear encoder, or the like. The present invention can readily change areas to be reproduced. Therefore, pictures, line drawings and the like can be selectively reproduced with ease from various areas of each original.

Having now fully described the invention, it will be apparentto one of ordinary skill in the artthat many changes and modifications can be made thereto without departing from the spirit orscope ofthe invention as setforth therein.

Claims (4)

1. In a method for scanning and reproducing a picture, said method including controlling the recording-side scanning means in accordance with picture signals obtained by photoelectrically scanning an original containing plural kinds of picture areas which should respectively be recorded in different processing modesandthen recording the resulting picture reproduced from the original, the improvementwhich comprises: dividing the entire area ofthe original by a plurality of lines, each of which extends in the direction of X-axis or V-axis, in different processing modes into a plurality of areas in accordance with plural kinds of picture areas to be recorded; storing X-address data and V-address data, which designate the plurality of lines respectively, in a registerorthe like; and storing codes representing respectivelythethus-divided areas and control data designating processing modes to be adopted to record the thus-divided areas in a memory orthe like; and comparing the X-address data and Y-address data, which have been stored in the register orthe like, with address signals obtained upon scanning the original and corresponding to scanning spots so that coded data representing respectively the divided areas are obtained; obtaining, from the coded data, control data designating the processing modes stored in the memory orthe like; and recording the reproduced picture in the processing modes, which are required for the respective divided areas, on the basis ofthe control data.

2. A method as claimed in Claim 1, wherein the processing modes include two types of different processing modes, one for recording halftone pictures and the otherfor recording line pictures.

3. A method as claimed in Claim 1, wherein the processing modes include three types of different processing modes, one for recording halftone pictures, anotherfor recording line pictures and the other for recording halftone pictures having a desired same dot area percentage which may range from 0% to 100%.

4. Amethodforscanning and reproducing a picture with reference to the accompanying drawings.