JPH01225284A - Picture processor - Google Patents

Abstract

PURPOSE:To clearly trim the edge of a picture by obtaining the linear equation of the edge of the picture according to a linear approximation and deciding a trimming range. CONSTITUTION:A picture signal obtained by a first scanning by an image sensor is inputted to a black and white discriminating means A to obtain the edge of the picture and store the coordinate of the obtained edge in a memory means B. A straight line operating means C uses the coordinates of the obtained edges to obtain an equation for the line edge of the picture according to the linear approximation. A trimming range operating means F uses the obtained linear equation to decide the trimming range. A trimming means H extracts the signal within the trimming range in the picture signal obtained by the scanning after a second time to change to a prescribed signal level and transmit this picture signal to a print means I.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is applied to a device such as a microfilm league, which outputs an image to a printer, CRT, etc. by reading the image with an image sensor. The present invention relates to an image processing device configured as described above.

(Technical Background of the Invention) Some microfilm leagues and the like read originals (images) with an image sensor.

In this case, a background is included around the document to be read. For example, in the case of negative microfilm, a black frame background appears around the document. Therefore, when an image sensor reads a document, this black frame is read as is, and this image signal is used to print an image or use a CRT (cathode ray tube)
When outputting to a cathode ray tube), there was an inconvenience that the black frame would appear as is. Furthermore, when using a PPC printer, there is a problem that the amount of toner used increases.

Therefore, a method of erasing this black frame has been proposed. For example, in Japanese Patent Application Laid-Open No. 62-144463, document position data is stored in memory for each main scanning line, and the data within the document position is determined from the input serial image signal. An image signal processing device that extracts only signals has been proposed.

However, this device is susceptible to noise caused by dust adhering to the microfilm or scratches on the microfilm, and there is a problem in that the edges of the trimming are not clean.

(Objective of the Invention) The present invention has been made in view of the above circumstances, and provides an image processing device that is not easily affected by dust or scratches and is capable of neatly trimming the trimming range around the document. The purpose is to provide.

(Structure of the Invention) According to the present invention, it is an object of the present invention to provide an image processing apparatus that scans and reads an image together with its background using an image sensor and outputs an image based on the read image signal. A black and white discrimination means for determining the edge of the image from the image signal obtained by scanning, a memory means for storing the coordinates of the determined edge, and a linear equation of the edge of the image is determined by a straight line approximation method using the stored coordinates of the edge. a linear calculation means, a trimming range determining means for determining a trimming range using the obtained linear equation, a memory means for storing the trimming range, and a trimming range determining means for determining the trimming range from among the image signals obtained by the second and subsequent scans by the image sensor. This is achieved by an image processing apparatus characterized by comprising a trimming means for extracting a signal within the range and changing the signal level to a predetermined signal level.

That is, from the coordinates of the edge of the document on the main scanning line, use the straight line approximation method to find the equation of the straight line on each side of the document.
These straight line equations determine the edge of the document and the trimming range.

(Example) Fig. 1 is a functional block diagram of the present invention, Fig. 1 is an overall configuration diagram of a microfilm league to which this is applied, Fig. 3 is an illustration of the main and sub-scanning directions on the screen, and Fig. 4 is an illustration of the main and sub-scanning directions on the screen. Figure 5 is a flowchart of the white discrimination operation; Figure 6 is a diagram explaining the principle of black and white discrimination means;
The figure is a flowchart of the black discrimination operation, Figure 7 is a circuit diagram for determining the coordinates of the four corners of the document, Figure 8 is a flowchart of the operation, Figure 9A is a flowchart of the trimming range calculation operation, and Figure 9B is an explanatory diagram of the coordinate system. It is.

First, the overall configuration will be explained based on FIG. 2. In this figure, reference numeral 10 is a light source, and the light from this light source 10 is transmitted through a condenser lens 12, a heat-insulating glass 14, a cold mirror 16,
The light is guided to a transmission screen 28 via the microfilm 18, a projection lens 20, an image reversing prism 22, and mirrors 24, 26, and an enlarged image of the microfilm 18 is formed on this screen 28.

A CCD line sensor 30, which is an example of an image sensor, is disposed on the back side of the screen 28 so as to be movable left and right. That is, this line sensor 30 is arranged long in the direction that traverses the screen 28, and the line sensor 30
performs main scanning by reading out the image in its length direction (main scanning direction) and sequentially outputting the image signal α as a time-series signal. The image signal α of this line sensor 30 that performs scanning is input to the CPU 34 via the input interface 32, where the seeding process is performed and the image signal is binarized. This binarized image signal β is output to the printer 38 via the output interface 36, where the image is printed out.
You can get a hard copy. Further, the binary signal β outputted by the CPU 34 can be recorded in an external storage device such as an optical disk device 40. Furthermore, the image may be displayed on a CRT or the like. Therefore, if necessary, a necessary original image may be read out from the optical disk device 40 and printed out by the printer 38 or displayed on a CRT.
A ROM 34 stores operating programs, etc., and a RAM 44 serves as a memory means.

First, the CPU 34 calculates the coordinates of the edge of the document every -1 scan line by the -th scan by the image sensor 30. Detection of this edge is performed by the black and white discrimination means A of the CPU 34, which is stored in the ROM 42 in advance as an operating program (FIG. 1).

The black and white discrimination means A is determined based on the coordinate X at which the image signal α changes from white to black or from black to white on the main scanning line. In other words, as shown in Figure 3, assuming that the χ axis is in the main scanning direction and the y axis is in the sub-scanning direction, the signal α (χ) at the coordinate χ on a certain main scanning line shows white or black over a certain distance. In some cases, it is determined that there is a connection. Here, it is assumed that the distance statement corresponds to No pixels on the line sensor 30.

FIG. 5 is an operation flowchart for determining the coordinate X at which the signal α changes from black to white during main scanning, and is used to determine the point Xa in FIG. First, start the main scanning upward from the position χ=0 of the lower edge of the screen 28 (step 100A), and then move to the next position χ=0.
If the signal α(1) due to pixel 1 is not white (step 102A).

104A), N=No (step 106A), α
If (χ) is white, subtract 1 from N (Step 108A)
, if white continues for No pixels (Step 110A), it is determined that there is a document from No pixels before this pixel, and χ-No/2 is adopted as the edge coordinate (Step 112A), this constant value N.

is equivalent to the distance sentence on the screen.

FIG. 6 is a flowchart for determining the coordinate X at which the signal α changes from white to black, and is used to determine the point Xb in FIG. That is, χ gradually increases in the main scanning line (step 120A),
If the signal α(χ) is not black (step 122-A)N
= No (Step 124A), if black, N = 1
(step 126A), and if black continues for the number of times corresponding to constant distance viewing (step 128A), then the number N.

It is determined that there is no document from before the pixel, and X-(3/2) No. is adopted as the coordinate X of the edge that changes from white to black.

As described above, the coordinates of the edge of the document are obtained for each main scanning line, and these are stored in the RAM 4 as the image edge coordinate memory means B.
Store in 4. In this way, sub-scanning is performed by moving the line sensor 30 in the y direction while memorizing the edge of the document.C
The PU 34 calculates the equation of a straight line on each side of the document using the method of least squares from the coordinates of the edges of the image thus calculated. That is, the distance ΔX between the straight line X=aY+b and the edge is determined, and the coefficients a and b are determined so that the sum of the squares of this ΔX is minimized. This operation is shown by linear calculation means C in FIG. This means C can be stored in the ROM 42 as an operation program for the CPU 34.

On the other hand, the CPU 34 also obtains the coordinates of the four corners of the document.

This operation is shown by the corner coordinate detection means in FIG. 1, and can be configured as shown in FIG. 7, for example. This means that the CPU
34 operation programs can be stored in the ROM 42, but it may also be constructed from discrete components according to this circuit diagram.

In FIG. 7, 50 is a main counter for determining the coordinate X during main scanning, and 52 is a sub counter for determining the coordinate Y during sub-scanning. The main counter 50 integrates clock pulses GK for sequentially reading data of each pixel of the line sensor 30, and uses the integrated value or the path 54 to register R (XI), F (X2), F (X3), R (X
4). This main counter 50 is cleared (returned to zero) every time the scanning of the -1 scanning line is completed, that is, as shown by LSYC in FIG. LSYC
The main counter 50 is cleared by a signal obtained by inverting the signal by an inverter 56. The sub counter 52 integrates the LSYC signal.

The integrated value Y is transferred to register R (Yl) by bus 58.
Transferred to R(Y2), R(Y3), and R(Y4). This sub-counter 52 indicates READY/;'BUSY (simply R/B
Cleared by a signal (abbreviated as ).

60 is a subtraction counter, and 62 is a setter for setting number No. These constitute the black and white discrimination means A. That is, the counter 60 subtracts one from the set number No. each time the image signal α continues to be white, and the counter 60 subtracts one from the set number No. every time the image signal α continues to be white.
is reset to No, and when the count value N reaches 0, it is determined as the first edge of the document in the main scanning direction. Moreover, this counter 60 is
Thereafter, the image signal α is inverted and subtracted in the same manner as follows, and when it becomes zero, it is determined as the end edge of the document in the main scanning direction. As a result, the W/B (white/black) signal which is the output signal of the counter 60 is at H level only during the period when the document is positioned on the main scanning line, as shown in FIG.

This W/B signal is initially set to H until the end of sub-scanning.
The coordinates at the level are detected by the flip-flop FF. These coordinates (x, yl) are the minimum Y corner as shown in FIG. 9B, and are stored in registers R(Xi) and R(Yl). Further, a rising edge of this W/B signal is detected by a rising edge detection circuit 64, and a falling edge thereof is detected by a falling edge detection circuit 66. Rise signal up which is each output
and the falling signal dwn, the coordinates at that time x2. x
3 is stored in register F (X2)F (X3). This coordinate x2. x3 is rewritten for each main scanning line. The coordinate x2 is the coordinate x2 on the immediately previous main scanning line.
is compared with the contents of the memorized register R(x2) in the comparator COMI, and when P<Q, that is, x2
While decreasing with each main scan, register R(X2)
, R(Y2) continues to be rewritten. As a result, the coordinates (x2.y2) of the minimum corner of χ in FIG. 9B are stored in registers R(X2) and R(Y2).

Register F stored in memory in synchronization with the falling edge of the W/B position
The content of (X3) is the coordinate x in the previous main scanning line.
3 is compared with the memorized contents of register R(x3) in comparator C0M2, and while P>Q, the contents of registers R(X3) and R(Y3) continue to be rewritten. The result registers R(X3) and R(Y3) are shown in Figure 9B (
F) The coordinates of the maximum X corner (x3.y3) are memorized.

Furthermore, each time the W/B signal goes to H level, its coordinates x, y
rewrites registers R(X4) and R(Yl) and writes W/B
When the signal no longer reaches H level, the coordinate X4. which reached H level last. Yl is stored as is.

The operation of determining the coordinates of the four corners in this manner is as shown in FIG. The coordinates of the four corners obtained in this way are stored in RAM44.
The information is stored in memory means E, which is a part of the.

The CPU 34 uses the obtained corner coordinates and the linear equation obtained by the linear calculation means C to obtain the trimming range (FIG. 1, trimming range calculation means F).
performs the operation shown in FIG. 9A. The coordinates of the four corners and the coordinates of the edges obtained as described above indicate the coordinates in the X direction where one image signal α becomes white or black consecutively No times. Therefore, CP
U34 is the position Xs of the 0 side edge of X on the main scanning line
.

Subtract No /2 (=l/2) from x2 and get XI
=X+ -172 X2 =X2-sentence/2 are set as new coordinates. In exactly the same way, the position of the edge on the increasing side of X x3. x, from (3/2) No (” (3/2) l
) and set the new coordinates to X3 = X3 - (3/2)I The straight line on each side is determined by the least squares method, which is an example of a straight line approximation method. That is, as shown in FIG. 9B, in Yl x Y x Y2 (step 302), the coordinates of the edge on each main scanning line are moved by X = X - 1/2 to obtain this straight line X = aIY + bl (
step 304), and in this range, X(alY+
Let bI be the trimming range (step 306).

In Yl x Y x Y3 (step 308), X=X-(3
/2) Move the coordinates with l and set X>a2Y+b2 as the trimming range (steps 310 and 312),
Similarly, when Y2 < Y < Yl and Y3 < Y < Yl (steps 314, 320), the coordinates are moved in steps 316 and 322, and the trimming range is determined as in steps 318 and 324.

In this way, the equation of the straight line on the four sides of the manuscript in Figure 9B
=aY+b are determined and these are stored in the memory means G consisting of RAM44.

In this embodiment, the linear equation is determined by the least squares method, but it goes without saying that the linear equation may be determined by using other approximation methods, such as the Tievisiev approximation method or other known approximation methods.

The CPU 34 performs steps 306, 312, and 31 using the coordinates of the four corners and the linear equation obtained by the first scan.
8,324 to determine the trimming range.

In subsequent scanning, the image signal α within this range is extracted and changed to a predetermined signal level, for example, a signal with approximately the same brightness as the background portion of the original, or to white (FIG. 1, trimming means H). The image signal α corrected to
4, the data is binarized and output to a printing means I such as a printer 38 to be printed.

Although the embodiments described above are applied to microfilm leagues, the present invention can also be applied to and includes image processing apparatuses such as PPC copying machines.

Further, as the image sensor, a two-dimensional area sensor may be used instead of the line sensor, and in this case, the area sensor may be fixed without being moved.

Further, the black and white discrimination means A determines whether the white or black image signal α is No.
Although the edge of the document is determined based on the fact that the document has been output repeatedly, the present invention is not limited to this.

Furthermore, when determining the edges of the image, the edges may be determined for each main scan as in this embodiment, but it may be configured to be determined for every - every main scan or every multiple main scans. The operating time can be shortened, and the present invention also encompasses such things.

Further, in this embodiment, the coordinates of the four corners of the document are determined by the circuit shown in FIG. 7, but they can also be determined by calculation as the intersection points of linear equations determined by a linear approximation method such as the least squares method.

(Effects of the Invention) As described above, the present invention calculates the linear equation of the edge of the image (original) by the linear approximation method in the −th scan, determines and stores the trimming range, and stores this in the second and subsequent scans. The purpose is to extract the signal within the trimming range and change it to a predetermined signal level, such as the brightness or white of the background part of the document, so if you want to memorize the coordinates of the edge of the document for every main scanning line, it is necessary to use the ratio. Even if the coordinates of the image edge change due to dust or scratches on the film, the equation of the image edge can be determined neatly as a straight line without being affected by it, and the edge of the image output to a printer etc. can be determined neatly. This allows for beautiful trimming.

[Brief explanation of the drawing]

Fig. 1 is a functional block diagram of the present invention, Fig. 1 is an overall configuration diagram of a microfilm league to which this is applied, Fig. 3 is an illustration of the main and sub-scanning directions on the screen, and Fig. 4 is the principle of black and white discrimination means. Explanatory drawings: Figure 5 is a flowchart of the white discrimination operation, Figure 6 is a flowchart of the black discrimination operation, Figure 7 is a circuit diagram for determining the coordinates of the four corners of the document, Figure 8 is the operation flowchart, and Figure 9A is the trimming. FIG. 9B, which is a flowchart of the range calculation operation, is an explanatory diagram of the coordinate system. A... Black and white discrimination means. B... Image edge seater memory means, C... Edge straight line calculation means, F... Trimming range calculation means, G... Memory means, H... Trimming means, α... Image signal, 30...Line sensor. Patent Applicant Fuji Photo Film Co., Ltd. Agent Patent Attorney Yama 1) Yu Fumi (and other names) Figure 2 Figure 3 Figure 4 Figure 5 Figure 5 Procedure Amendment Form) Commissioner of the Japan Patent Office Kuni Ogawa Husband 2, Name of the invention Image processing device 3, Relationship with the person making the amendment Patent applicant address 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name (52G
) Fuji Photo Film Co., Ltd. Representative: Sho Ohnishi 4, Agent Address: Yamato Bank Toranomon Building, 1-6-21 Nishi-Shinbashi, Minato-ku, Tokyo (Telephone: 591-7556) 6, In column 7 of ``Brief explanation,'' page 17, lines 15-16 of the specification of amendments, ``This is shown in Figure 1'' is corrected to ``This is shown in Figure 2.'' /airybe

Claims (1)

[Scope of Claims] An image processing device that scans and reads an image together with its background using an image sensor, and outputs an image based on the read image signal, comprising: A black and white discrimination means for determining the edge of an image, a memory means for storing the coordinates of the determined edge, a linear calculation means for calculating a straight line equation of the edge of the image by a straight line approximation method using the stored coordinates of the edge, and the determined straight line. a trimming range determining means for determining a trimming range using an equation; a memory means for storing the trimming range; An image processing device comprising: trimming means for changing the signal level to a predetermined signal level.