JPS61163473A - Picture geometry correcting method - Google Patents

Abstract

PURPOSE:To execute the geometry correcting processing of a picture, such as shaping of a distorted picture in a CAD system, etc., by designating a coordinate value of four points of the picture and four regular points corresponding to it, and using and analyzing a quadri simultaneous equations. CONSTITUTION:A command is inputted from an input device 5 to a micro-computer 1, and a picture (original picture) of a processing object stored in a picture memory 2 is displayed on the screen of a display device 4. Next, four points Q1-Q4, being standards of the original picture are designated and the coordinates value is stored in a data memory. Continuously, the coordinates value of regular points P1-P4 corresponding to the points Q1-Q4 is stored in the data memory. Here, on the screen of the device 4, the pattern with P1-P4 as peaks is displayed overlapping with the original picture. Thereafter, a practical geometry correcting processing is executed by a computer 1 by using the quadri simultaneous equations. The picture data on the way are stored in a special area of the picture memory 2, the correcting picture during the processing is also successively displayed on the screen of the device 4 overlapping with the original picture, and the geometry correcting processing can be executed.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a method for geometrically correcting an image.

〔the purpose〕

In the field of image processing, for example, in CAD systems, there are many cases where it is desired to perform geometric correction processing on a single image, such as shaping a distorted image.

The purpose of the present invention is to obtain the coordinate values of four points in one image.

An object of the present invention is to provide an image geometric correction method that can perform geometric correction of such an image simply by specifying the coordinate values of the corresponding regular points.

〔composition〕

According to the image geometric correction method of the present invention, four specified points Q+(x+*yq+), Q7cXq of the image to be processed
t+yqz)-Qa(Xqt+Vq+).

Q, Cxq□wY11g) are the corresponding four specified normal points PL (Xp t + Vp I)
, Pz (Xp t + Vp ,) - P3 (IP a
*Np*), Pa (xpa+Ypa). Furthermore, the coefficients of the two linear four-dimensional simultaneous equations (1) and (■) are solved using each of the above coordinate values.

A-xp,'YP++B-xpl+C'Yp++D=X
q+A'XP? 'ypt+Box,,+C*ypz+
D=xt2A' Xys * ' Vwp * +B
"Xp H+C"Ip 3 +D=Xq xA' X
p a ” Np a +B ” Xp 4 +C'
Yp 4 +D=)Cl a...(1) E'XPI "Vwp+ +F'Xp++G'Yp++
H=Yq+E"x,t"y,,+Fax,,+G"y
wpt+H=yq,.

E' X1p 3'' 7p * +F' Xp i
+G” 'ip * +H=71 zE ”Xp
4' 7p 4 +F' Xp a +G' Y
p a +H=Vq a...(■) Then, the coordinate values (x+y) of each other point in the above image are determined by the normal coordinate values (x' + y') using the linear equation (III) and (rV). ) is corrected.

x' =Axy+Bx+Cy+D ・-・(m
)y'=Exy+Fx+Gy+H-(IV) An embodiment of the present invention will be described below using one drawing.

FIG. 1 is a flowchart showing an outline of the process;
The figure is a block diagram showing a schematic configuration of a processing system.

The processing system shown here is mainly configured with a microcomputer 1 having a general configuration including an arithmetic control section, data memory, program memory, input/output interface, etc.

The image geometric correction processing is executed in the microcomputer 1 based on a program, but it is of course possible to entrust specific processing to dedicated hardware or firmware. 2 is an image memory in which an image to be processed (M image) and image data during and after processing are stored;
Can be accessed from the side. A display device 4 is physically integrated with an input device 5 such as a keyboard.

6 is a printer device. 7 is an image input device such as a scanner, and image data inputted by this device is stored in the image memory 2.

Next, the processing will be explained in order. First, a command is input from the human-powered device 5 to the microcomputer to display the image to be processed (referred to as an original image) stored in the 1-image memo I72 on the screen of the display device 4 (step 10). ! The solid line figure of I is displayed as Miil. Next, specify the four reference points of the original image, for example, Q, , Q, , Q3, and Q4 in Fig. 3 (step 11).
), specifically, move the cursor on two screens through the input device 5.

〜Q4, and calculate its coordinate value (Xqt
*) Instructs the microcomputer 1 to read 'qt) to (XqatVqa). The read coordinate values are stored in the data memory of the microcomputer.Next, the cursor is sequentially set at four regular points P, ~P4 (see Figure 3) corresponding to Q, ~Q1, respectively. and each coordinate value (Xp1*7pl) ~ (Xpa*Y
These coordinate values are also stored in the data memory within the microcomputer.

As a result, on the screen of the display device 4, a figure whose vertices are P, -P4 as shown by broken lines in FIG. 3 is displayed superimposed on the original image.

Thereafter, actual geometric correction processing is executed by the microcomputer 1, but the intermediate image data is stored in the image memory 2.
As the process progresses, the corrected image that is being processed is also sequentially displayed on the screen of the display device 4, superimposed on the original image.

First, microcomputer 1 is the point Q of the original drawing.

~Correct Q4 so that it overlaps the corresponding normal points p, -p, (Step 13) Next, solve the two four-dimensional simultaneous equations (I) and (II) by the sweep method,
Calculate each coefficient A-H (Step 14) Next, shift each other point of the original image to a regular point (Steps 15 to 17)
), the coordinate value (X') of the regular point to which the coordinate value (x, y) of the original point is transferred.

y') is calculated by the above equations (m) and (TV) (step 15), and the density N of the normal point (x' + y') is calculated in step 16 by linear interpolation as follows: Desired. As shown in Figure 4.

Four points p, (x.

y), Pz(X+1+y), P? (XI y+1).

Let the concentration of p, (x+1.y) be N I* N t * N
-4tN4. The distances in the X direction and Y direction from the regular point (x' + y') to p1 to p4 as shown in the figure "K I * Q II!? -Q y l +
QV? shall be. first.

Interpolation is performed between P+ and P7 using the concentration gradient in the X direction to obtain the concentration NX.

NX, = Q, ・N, +Q, ・N.

Similarly, interpolation is performed between P, , P and the density gradient in the X direction to obtain the density N)I7.

NX, = fl, ・N, +QX□・N.

Interpolation in the Y direction is performed using the density NXl+NX2. Therefore, the density N at the normal point (x' + y-') is determined by the following equation (V).

N=fi, -N,,+Q,,, ・NX I=Qv
l (QX, ・N, +Qx, ・N,)+Qv,
(Q,, ・N, +QX, -N,)...(V) Note that if the four neighboring points cannot be taken, the density of point p is directly adopted as N.6 Also, in this example, 5
When the image appears outside the 12×512 screen, the density is set to O.

When it is confirmed in step 17 that the correction processing for all points on the original image has been completed, the processing ends. The processing results are obtained in the image memory 2, and can be printed by the printer device 6 or transferred to an external storage device (not shown) if necessary.

〔effect〕

As explained above, the present invention includes four original drawings.

Geometric correction of one image is possible by simply specifying four corresponding regular points, and great effects can be obtained if it is introduced into an image processing system.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the flow of processing in an embodiment of the present invention, FIG. 2 is a block diagram showing a schematic configuration of a processing system according to the embodiment, FIG. 3 is an explanatory diagram of point specification,
FIG. 4 is an explanatory diagram of concentration determination using the linear interpolation method. 111. Microcomputer, 2... image memory. 4...Display device, 5...Input device. 6... Printer device, 7... Image input device. Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] (1) Four specified points Q_1 (x_q_1, y
_p_1), Q_2(x_q_2, y_q_2), Q_
3(x_q_3, y_q_3), Q_4(x_q_4,
y_q_4) to the corresponding specified regular 4
two points P_1(x_p_1, y_p_1), P_2(x
_p_2, y_p_2), P_3(x_p_3, y_p
_3), corrected to P_4 (x_p_4, y_p_4),
Coefficients A and B of the following two four-dimensional simultaneous equations [1] and [2]
, C, D, E, F, G, H, solve A・x_p_1・y_p_1+B・x_p_1+C・y
_p_1+D=x_q_1A-x_p_2・y_p_2
+B・x_p_2+C・y_p_2+D=x_q_2A
・x_p_3・y_p_3+B・x_p_3+C・y_
p_3+D=x_q_3A・x_p_4・y_p_4+
B・x_p_4+C・y_p_4+D=x_q_4...[
1] E・x_p_1・y_p_1+F・x_p_1+G・y
_p_1+H=y_q_1E・x_p_2・y_p_2
+F・x_p_2+G・y_p_2+H=y_q_2E
・x_p_3・y_p_3+F・x_p_3+G・y_
p_3+H=y_q_3E・x_p_4・y_p_4+
F・x_p_4+G・y_p_4+H=y_q_4…[
2] The coordinate values (x, y) of each other point in the image are calculated using the following formula [3],
Correct the coordinate values (x', y') using [4]. x'=Axy+Bx+Cy+D...[3] y'=Exy+Fx+Gy+H...[4] An image geometric correction method characterized by obtaining a geometrically corrected image of the image.