JPH03213859A - Trimming range setting device for image - Google Patents

Abstract

PURPOSE:To eliminate the need for a mask plate by displaying the image signal of an original read by an image read means on a monitor after storing the signal temporarily in an image memory, and calculating the range of the original to be read by the image read means of a scanner according to data on a specified trimming range. CONSTITUTION:The image signal of the original read by the image read means 9 is stored temporarily in the image memory 24 and then displayed on the monitor 25, and an arithmetic means 5 calculates the range of the original to be read by the image read means 3 of the scanner according to the data on the trimming range specified by a coordinate value specifying means 26 for the displayed image. The data from the arithmetic means 5 is supplied to the scanner, wherein the image read means 3 trims and reads an image automatically to obtain a color-separated image which is already trimmed. Consequently, the color-separated image which is trimmed directly by the scanner is obtained without forming a mask plate for trimming.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for setting a trimming range of an original image read by a scanner.

(Prior art) In order to print a color original image, it is necessary to create a plurality of separation plates for each specific color of the original image, for example, three or four types. So-called color separation scanners have been used in the past, which perform color separation using electrical signals.

(Problem H to be solved by the invention) However, with conventional scanners, it is difficult to arbitrarily select only a predetermined portion of the set original image and read and expose the image signal, which is necessary in printing techniques. In order to perform detailed trimming, the conventional method has been to create a trimming mask version separately from the separated version created by the scanner, and then perform trimming from the separated version. There was a problem in that it required time and cost.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a trimming range setting device for obtaining a decomposed image directly trimmed by a scanner.

(Means for Solving the Problems) To achieve this object, the present invention includes: an image reading means for reading a predetermined range of a document; an image memory for storing image signals of the document scanned and read by the image reading means; A monitor that displays the image by successively displaying the image signals stored in the image memory, and a coordinate value specifying means that displays a trimming mark superimposed on the image displayed on the monitor and specifies the coordinate values of the trimming range of the image. An image trimming range setting device is provided, comprising: a calculation means for calculating a range of a document to be read by an image reading means of a scanner based on data from the coordinate value specifying means.

(Function) In the present invention, the image signal of the document read by the image reading means is once stored in the image memory and then displayed on the monitor, and the trimming range specified by the coordinate value specifying means is applied to the displayed image. Based on the data, the calculating means calculates the range of the document to be read by the image reading means of the scanner. The data from this calculation means is then given to the scanner, and in the scanner, the image reading means automatically trims and reads the image, thereby making it possible to obtain a trimmed color-separated image.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing an embodiment of an apparatus incorporating the image trimming range setting device of the present invention. In the figure, 1 is a reading scanning drum, 2 is an exposure scanning drum, 3 is a reading head, and 4 5 is an exposure head, 5 is a control device, 6 is a drum drive section, 7 is an image signal processing section, 8 is a film exposure section, 9
is a one-dimensional image sensor, 10 is a lens, 11 is a stepping motor, 12 is a rotary ethancoder, 13 is a linear encoder, 14 is a preamplifier, 15 is a peak hold circuit, 16 is an A/D (analog-to-digital converter), 17 is a bidirectional bus driver, 18 is a buffer memory, 19 is an address counter, 20 is an address selector, 21 is a stamping motor, driver, 22.23
24 is an input/output controller, 24 is an image memory, 25 is a monitor, 26 is a coordinate specifying device, and 27 is a gate. In addition, F
is the original picture that should be trimmed.

The reading scanning drum l is intermittently driven at a predetermined period by a stepping motor 11 during pre-trimming scanning to be described later, and is driven at a predetermined period by a drum drive unit 6 together with the exposure scanning drum 2 during reading exposure (hereinafter referred to as main scanning). It rotates at a constant speed at a synchronous speed.

The reading head 3 and the exposure head 4 are driven by a head drive mechanism (not shown), and are intermittently scanned at predetermined intervals in the direction of the arrow in the figure in synchronization with the rotation of the scanning drum 1.2 during main scanning.
Alternatively, the scanning drum l, moving continuously at a predetermined speed,
Scan the surface of 2.

At this time, the image signal S read from the original image F by the reader 3 becomes an image signal S3 which has been subjected to predetermined processing in the image signal processing section 7, and a predetermined portion is extracted by the gate 27 to form a trimmed image signal. After S7, the image of an unexposed film (not shown) is supplied to the film exposure unit 8 and held on the scanning drum 2 by the exposure head 4, and the exposed film for plate making is color-separated. get. Therefore, the main scanning operation is the same as that of a normal scanner when the gate 27 is open.

-Dimensional image sensor (hereinafter referred to as Is) 9 is a CCD
It comprises a large number of charge conversion elements made of shape-dimensional solid-state image sensors and the like and arranged in a straight line at a predetermined pitch, and a signal transfer unit that sequentially reads out photoelectric conversion signals from these photoelectric conversion elements in accordance with a clock C1, It functions to obtain an image signal S by reading image signals line by line from the image of the document F projected by the lens IO.

Note that here, the signal S is a scanning start signal for each line of I39, and the signal EN is also an end signal.

The stepping motor 11 is operated by the controller 5 during pre-scanning.
1022, each time the reading of one line of image signal S by 139 under drive control via the driver 21 is completed,
The scanning drum 1 is rotated by a predetermined rotation angle in the direction of the arrow, and the image signal 139 is read over the entire area of the original image F.

In the above description, the image signal reading scan of one line by +39 will be referred to as a line scan, and the image signal read scan by rotating the scanning drum l will be referred to as a surface scan hereinafter.

The rotary encoder 12 functions to detect the rotational angular position of the scanning drum l and to supply a position signal Pv representing it to the control device 5.

The linear encoder 13 serves to detect the digit 1 of the reading head 3 and to supply a position signal PII representing it to the control device 5.

The peak hold circuit 15 receives +3 via the preamplifier 14.
The image signal SP from IS9 is received, and the peak value of the image signal S is held in synchronization with the readout clock C1 of IS9.

is operated such that only the peak value for each pixel of is supplied to the A/D 16.

The bidirectional bus driver 17 supplies an image signal converted into 4-pin digital data to the buffer memory 18, and when the image signal is read from the buffer memory 18, the A/D 16 supplies it to the control device 5. work to do.

The address counter 19 counts the clock CK, operates the address selector 20 based on the count data, and selects one of the image signals to be written into the buffer memory 18.
It functions to specify the address for a line. Note that the address selector 20 also functions to read one line of image data from the buffer memory 18 according to the read address data Rt from the control device 5.

The image memory 24 functions to accumulate the image signal data read from the buffer memory 18 and to store the image signal data of the entire document F.

The monitor 25 functions to reproduce the image of the original image F based on the image signals stored in the image memory 24.

The coordinate specifying device 26 is equipped with an input operation mechanism such as a keyboard switch and a joystick, and is used to arbitrarily move the position of a rectangular trimming mask of a preset size that is being reproduced on the image projection surface of the monitor 25 by the control device 5. It functions to generate the position signal PXY.

The gate 27 is an analog gate capable of gating the image signal S, and gates the gate signal G supplied from the control device 5.
, and functions to generate a trimmed image signal S, which is obtained by extracting a portion of the image signal S3 at a predetermined timing.

The control device 5 operates according to various programs incorporated as software or hardware, and is configured to have various data processing functions and control functions for other devices.

Next, the operation of the apparatus shown in FIG. 1 will be explained.

The apparatus shown in FIG. 1 operates in three modes: the pre-trimming scan described above, the subsequent trimming operation, and the main scan for exposing the trimmed image.
First, a document F to be trimmed is set on the operating drum 1, and then pre-trimming scanning is started.

The image of the original F is formed by the lens 10 on the photoelectric conversion unit 139. At this time, +39 is arranged so that the photoelectric conversion elements arranged in a straight line are parallel to the rotation axis of the scanning drum 1. Further, it is held at a position away from the surface of the scanning drum l by a distance determined by the reading magnification of the original F and the focal length of the lens lO.

Therefore, the control device 5 supplies the start signal S7 and the end signal E to the 139 in synchronization with the clock CK to perform line scanning, and also supplies the start signal S7 and the end signal E to the 139.

Or generate a control B signal in synchronization with the end signal EH,
The stamping motor 11 is driven via the I/D 22 and the driver 21, and the scanning drum 1 is rotated by a constant angle to perform surface scanning. At this time, the control signal 5 takes in a signal P7 representing the rotational angular position of the scanning drum l from the rotary encoder 12, controls the rotational angular position of the scanning drum l according to a preset document enlargement magnification, and controls the rotational angle position of the scanning drum l by correct scanning lines. The area is scanned one by one.

As a result, the image signal S from +39 is read out for each pixel of the original F in synchronization with the clock C1.

is sequentially taken out one line at a time, and this signal S
P is peak-held for each pixel by a peak-hold circuit 15 via a preamplifier 14, digitized by an A/D 16, and then supplied from a bidirectional bus driver 17 to a buffer memory 18. At this time, the write address of the buffer memory 18 is controlled via the address selector 20 by the data of the address counter 9 which is powered by the clock C8, so the image signal S2 from +59 is different for each pixel. The data will be taken into the buffer memory 18 in 1947 minute increments at each address.

Therefore, every time one line of image signal is taken into the buffer memory 18, the control device 5 continuously outputs address data R,
is supplied to the address selector 20 and the buffer memory 18
The image signal for one line is read out from the image signal, processed as a collection of appropriate pixel data according to the document size and exposure magnification set in advance, and transferred to the image memory 24 via 11023.

Therefore, when the above pre-trimming scan is completed for the entire document F, the image information of the document F is stored in the image memory 24 as a predetermined number (MXN) of pixel data, as shown in FIG. become. In FIG. 2, if P is the starting point of the pre-trimming scan on the surface of the scanning drum l, this P is the origin, and the line scanning direction due to +39 is also X, the surface scanning direction due to the rotation of the scanning drum l. A coordinate system can be defined with y as y, and if the number of photoelectric conversion elements of IS9 is N, the number of pixels per summer is N, and if the number of scanning lines is M, the total number of pixels is as described above. Thus, there are MXN pieces. Therefore, the position of arbitrary pixel data on the image plane read by the pre-trimming scan can be expressed by the scanning line number l and the pixel number J within each scanning line, as shown in FIG. My number! is the signal Pv obtained from the rotary encoder 12, and the number J corresponds to an arbitrary position of the photoelectric conversion element of IS9, respectively.

Now, when the pre-trimming scan is completed in this way, the next step is to proceed to the trimming operation, and the control device 5 uses the image memory 24
An image of the document F and a trimming mark of a preset size are displayed on the monitor 25 based on the data read from the monitor 25.

Next, the coordinate specifying device 26 is operated by the operator, and the trimming mark on the image projection surface of the monitor 25 is moved in accordance with the position signal PXV, and trimming is performed on the image surface of the document F obtained by the previous scanning, and an appropriate trimming range is set. The designation is made.

This designation is manually input to the control operation 5 by an operator's designation completion operation, for example.

Therefore, the control device 5 determines the line number of the reference point P7 in the trimming range based on the position signal pH input at that time! , and pixel number J, and then calculate and store coordinate values Xv and Yt in the coordinate system shown in FIG.

When the calculation of this reference point PT (XT, Yr) is completed, the control device 5 switches to main scanning, and the scanning drum 2
After an unexposed film (not shown) is attached to the drum drive section 6, the scanning drum 1.2 is driven to rotate at a constant speed, and the image signal S from the reading head 3 is transferred from the image signal processing circuit 7. film exposure section 8 through gate 27 of
The exposure head 4 starts exposing the trimmed image.The operation at this time will be described below.

First, for explanation, as shown in Fig. 3, take an appropriate origin D on the surface of the scanning drum l, set the feeding direction of the scanning drum 3 to A coordinate system is defined in which the scanning direction is Y, so that the position of a scanning point on the surface of the scanning drum 1 can be displayed in XY coordinates.

Then, the X and Y coordinates of this scanning point are the position signal P obtained by the near encoder 13.

can be immediately detected by the position signal Pv from the rotary encoder 12, and the reference point P for trimming scanning
y can be calculated.

However, since 139 is often used in a fixed state, it cannot be used as the origin of the scanning drum 1.

and the origin P of the pre-scanning raw machine do not match, and therefore, the third
As shown in the figure, the origin P is offset from the origin D.
) (Xo, Yo), therefore, the coordinates of the trimming reference point Pt in the xY coordinate system are (XT,
Yf). Therefore, at the time of scanning before trimming, the position coordinates (x,,y,) of the origin P0 in the xY coordinate system are
By determining this from the position signals P and PV and storing this in the control device 5, the reference point P can be easily calculated using equation 0.

Therefore, when the control device 5 starts main scanning, it generates a gate signal G7 by detecting this reference point P, and generates a gate signal G7.
is operated at a predetermined timing, extracts a part of the image signal S, extracts a trimmed image signal ST, and exposes it to the unexposed film by the exposure head 4 so that the trimmed separated plate is immediately exposed. The operation at this time will be explained with reference to timing charts shown in FIGS. 3 and 4.

In Fig. 3, the scanned portion of the document F before trimming is
, the range specified by the trimming mark, that is, the trimming part, is F7, and the trimming size is dx, dy
shall be. It is assumed that the document F has no pattern except for the pre-trimming scan area F.

Then, the image signal S obtained by main scanning this has a waveform as shown in FIG. 4, for example. In addition, in this Figure 4,
L is the period required for one rotation of the scanning drum 1, that is, l
This is the scan line period.

In this state, when the control device 5 detects the reference point P7 as described above, it sends a pulse having a width equal to the time Tdy necessary for the scanning point to move by the distance #dy from that time t for one scanning line period. Gate signal G occurs every time I work! Then, this pulse generation is repeated for a time equal to the time Tdx during which the scanning point moves by a distance Hdx in the X direction from the reference point Py.

As a result, the gate 27 is turned on every time a pulse of the gate signal G appears, allowing the image signal S to pass through, and the trimmed image signal ST, a part of which is extracted at a predetermined timing.
The unexposed film on the scanning drum 2 is directly exposed to the trimmed image.

The exposure state of the scanning drum 2 to the unexposed film when the gate 27 is off may be arbitrarily determined depending on the trimming plate creation conditions.
For example, it may be left unexposed or completely exposed.

Therefore, according to the above embodiment, arbitrary trimming can be performed in the color separation operation by the scanner, and only the trimmed portion can be exposed immediately, and the image signal reading operation by the pre-trimming scan is performed by I39 having an extremely fast scanning speed. Since the scanning is completed by line scanning and surface scanning by only one rotation of the scanning drum l within one rotation, the time required for pre-scanning can be sufficiently shortened.

Incidentally, in this embodiment, the image signal obtained in the pre-trimming scan is reproduced on the monitor 25, and if the pixel density of the reproduced image is low, the accuracy of trimming will also be reduced.

However, for example, if a relatively small number of charge conversion elements, 512, is used as IS9, then 10c
When scanning a m x 8 cm original, the error in the trimming range allowed when the exposure magnification is 100% is ±0 because the resolution pitch of IS9 is approximately 0.2-.
．． It is within 1 m and can maintain sufficient accuracy for practical use.

In addition, when scanning an A4 size (210x297) with the short side parallel to the rotation axis of the scanning drum l using the same I39, the resolution pitch of IS9 is about 0.41 mm, so the error in the trimming range is ±0. It is within .205 degrees, and sufficient accuracy can be obtained even in this case.

On the other hand, since a black and white monitor is sufficient as the monitor 25, the storage capacity required for the image memory 24 is the same as that of the monitor 25.
When the total number of pixels of the image to be reproduced is set to 512 x 512, there are 8 floors for each pixel! Since it is sufficient to use 413 bits and 1 bit for the trimming mark, a total of 128 bytes is sufficient, and there is no need to use a large storage capacity.

Here, the apparatus shown in FIG. 1 is configured to perform trimming using a normal plate-making scanner equipped with scanning drums 1 and 2. Therefore, the scanning drum 1 performs operations from pre-trimming scanning to main scanning. Although the pre-trimming scanning mechanism is used as it is set in the main body, in the present invention, only this pre-trimming scanning mechanism is configured as a dedicated device.

Therefore, in a practical example using a dedicated device like the present invention, the pre-trimming scan and the main scan are performed in separate devices, so it is necessary to use a rotary machine to detect any point on the scanning drum. Encoders, near encoders, etc. are also required for each device, and additional data regarding the correspondence of scanning positions between both devices is stored in the control device of the device that performs main scanning. Although necessary, since the pre-trimming scan and the main scan can be performed independently, flexibility can be given to the plate-making work.

(Effects of the Invention) As described above, in the present invention, the image signal of the document read by the image reading means is stored in the -H image memory and then displayed on the monitor, and the coordinate value specifying means is sent to the displayed image. The calculation means calculates the range of the document to be read by the image reading means of the scanner based on the data of the trimming range specified by the scanner. The means can automatically trim and read the image, and there is no need to create a mask plate when trimming separated plates of color originals as in the conventional process (this reduces the amount of mask film used in plate-making work). In addition, it is possible to designate the reading range of the document in the scanner independently of the color separation work, and improve the work efficiency of the scanner.Furthermore, the present invention By applying this device to a computer layout scanner system equipped with a large magnetic disk drive, it is possible to import only the cropped image data as an input image, reducing the amount of retained data and making effective use of the magnetic disk pack. Compared to performing image trimming processing using only this layout scanner system, using the device of the present invention as a preparatory device allows trimming to be performed more easily and simply. Since it does not require a large-scale configuration, it has an excellent effect of being inexpensive.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of an apparatus incorporating the image trimming range setting device of the present invention, Fig. 2 is a schematic diagram showing sampling points in the pre-scanning portion of a document, and Fig. 3 is a scanning FIG. 4 is a schematic diagram showing a pre-scanning portion and a trimming portion of a document on a drum. FIG. 4 is a timing chart showing the relationship between an image signal, a trimming image signal, and a gate signal. l, 2-111 Scanning drum 3----1 Reading head 4---Exposure head 5---Control device 6 -Drum drive unit 7---Image signal processing section Film exposure section primary Original image sensor (Is) Lens 11--Stepping motor Rotary encoder Linear encoder Preamplifier Peak hold circuit A/D (Analog-to-digital converter) Bidirectional bus driver Buffer Memory address counter Address selector Stepping morph driver ■10 (Human output controller) Image memory 25-----1-Monitor coordinate designation device 27---1---Gate 2 Figure 3

Claims (1)

[Claims] Image reading means for reading a predetermined range of a document; an image memory for storing image signals of the document scanned and read by the image reading means; and an image memory for reading image signals stored in the image memory. a monitor for displaying an image; a coordinate value specifying means for displaying a cropping mark superimposed on the image displayed on the monitor and specifying the coordinate values of the cropping range of the image; An image trimming range setting device comprising: arithmetic means for calculating the range of a document to be read by an image reading means of a scanner;