JPS5849070B2 - Image displacement detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides image position detection for detecting whether or not the image obtained by imaging is at a regular position with respect to the screen when imaging is performed with a television camera (hereinafter referred to as a camera). Regarding the method〇 Conventionally, for three-tube color cameras, R (red), G
An image pickup tube is provided for each color (green) and B (blue), and in order to detect registration caused by image position deviation of each image pickup tube, the image output of the G image pickup tube is generally used as a reference.
The image output deviation of the R and B image pickup tubes with respect to this is detected, and the relative image position difference of each image pickup tube is determined.

However, although it is possible to determine the relative difference in image position using conventional means, it is not possible to determine the absolute image position deviation from the normal image position. Since the image position is corrected, it is time-consuming and has drawbacks such as the inability to fully automate camera adjustment.

The present invention has the purpose of fundamentally solving the conventional drawbacks, and provides an extremely effective image position detection method that can automatically determine the absolute image position deviation of the imaging tube. ○ Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

FIG. 1 is a diagram showing an example of a test pattern used in the present invention, in which two line segments L1 and L are perpendicular to each other on a white plane.
When detecting the imaging position, the test pattern TP and the camera are placed directly facing each other, and the test pattern TP is placed in the imaging screen of the camera. After making sure that it fits, take an image.

2 and 3 are diagrams showing the principle of the present invention,
Paying attention to any pattern P in the test pattern TPK$-, when the image pickup tube is at the normal image position, the resulting figure F1 is shown by the broken line, and the figure F2 obtained by imaging at the irregular image position is shown by the solid line. The left button and the right line segments L1 and L2 toward the V-shaped pattern indicated by figure F1 intersect at the midpoint of each, and the apex A of the V-shaped pattern Assuming left and right perpendicular lines P1 and P2 that have an equal distance V and a length within the height of the V-shaped pattern, these perpendicular lines P1 and P2 are connected to line segments L1 and L2. When the length of the upper and lower buttons from the intersection point is h, the left and right line segments L3 and L4 of the button on figure F2, and the perpendicular line P1,
By the intersection with P, , four right-angled isosceles triangles T1 to T4 are formed on the left and right upper buttons and below.

Here, connect the lower ends B and C of perpendicular lines P1 and P2 with a straight line,
The distance between the point DE where this straight line and the line segments L, , L2 intersect and the lower ends B and C is a1, the area of the lower right-angled isosceles triangle T4 is S4, and the horizontal distance between the apex A and the apex F of the figure F2. of,
{H, if the distance between the intersection G of the line extended horizontally from the vertex A and the line segment L4 and the vertex A is X1, and the vertical distance between the vertex F and the intersection G is JV, then the vertex F, the intersection G, and The triangle formed by the intersection H of the straight line extending the vertex A horizontally and the line segment L3 becomes a right isosceles triangle, and the following equation holds true from the illustrated relationship.

In addition, in Figure 3, which is similar to Figure 2, the horizontal distance between the intersection ■ of the straight line connecting the lower ends B and C and the line segment L4 and the intersection E is X2, and the horizontal distance between the intersection D and the vertex A. If the area of the lower right-angled isosceles triangle T2 is 82, then the following equation holds true from the relationship shown.

That is, {H indicates the horizontal deviation of the figure F2 with respect to the figure F1, AV indicates the similar vertical deviation, and the isosceles right triangle Tll shown in FIGS.
Each area S1, S2, S3, S4 of T2tT3 and T4
The difference between the normal image position indicated by the figure F1 and the irregular image position indicated by the figure F2 is determined by predetermined calculations shown by equations (9) and (10) based on the desired area of the figure F1.

In the actual t''L column, for convenience of explanation, a right-angled V-shaped pattern P is used, but this is made up of line segments from left to right that have a predetermined angle θ to each other. A V-shaped pattern may be used, and in this case, the equations (9) and (10) described above become as follows.

FIG. 4 is a block diagram of a circuit configuration based on the above principle, in which a test pattern TP is imaged by a color camera CAM as a television imaging system, and then transmitted from a camera control unit CCU to multiple channels, that is, each color of R, G, and B. The video signals are taken out individually and sent to multiplexer MPX.
After selecting one of them according to The signal is generated by the signal generator BSG and fed to the phase difference pulse generator PG to operate as shown in FIG. 5, which shows the waveforms of each part as a time chart.

The output of the social signal generator BSG is also connected to the multiplexer MP.
X, and under the control of the small computer CPU described below,
It is also possible to select a signal.

For Figure 5, the upper part is the same as Figure 2 and Figure 3.
Perpendicular lines P1 and P2 formed by the bar signals and a figure F2 formed by the video signal obtained by imaging the test pattern TP are shown, and the corresponding scanning lines L1 to Ln are also shown. Among the G and B color video signals, for example, only the G video signal is focused.

That is, as shown in FIG. 4, under the control of a small computer CPU using a microprocessor or the like, the multiplexer MPX selects the G video signal as a specific channel, and the gate G1 selects the test pattern TP shown in FIG.
It may be turned on only during the scanning period for a specific pattern in the center, for example, the pattern in the center, so that only the video signal obtained by the pattern in the center passes through the gate G1. For each Lo, according to the line segment L3 of the figure F2, it occurs in the phase relationship of Figure 5, ~ao,
It is applied to the phase difference pulse generator PG.

Furthermore, although the bar signal (b) is generated with the same phase for each scanning line L1 to Ln, for the reason described later, in reality, the bar signal (b) is generated at an earlier timing by a time t and is outputted from the phase difference pulse generator. In other words, in this embodiment, the phase difference pulse generator PG starts generating pulses with the output C and ends with the output a, so the output C is always output. This is a signal whose phase is more advanced than a.

On the other hand, it is possible to generate a signal so that the output C is always delayed in phase from the output a, or to use a delay circuit to generate the output a.
may be delayed.

In addition, if the phase difference pulse generator PG is designed to be able to switch polarity at the timing when the phase difference between output a and output C is zero, the output a
Or, there is no need to shift the phase of C. On the other hand, the phase difference pulse generator PG outputs a1 to
A phase difference output d1~do indicating the phase difference between an and the output C is generated, and this is sent to a time/voltage converter such as an integrating circuit (hereinafter referred to as
TVC) Give to T/V.

Note that the above operation is performed in the same way even if the button is pressed on the line segment L4 for each of the scanning lines L1 to Ln.

The TVC-T/V generates a voltage according to each pulse width of the phase difference outputs d1 to dn, which is sampled by the sampling circuit SP using the outputs 31 to an as sampling pulses, and then converted to an analog-to-digital converter (hereinafter referred to as ADC)A
/D, where the voltage corresponding to each phase difference is
For example, it is converted into an 8-bit digital signal and then provided to a small computer CPU.

However, TvC-VV is reset by a signal at an appropriate timing generated from the horizontal drive signal HD.

The small computer CPU operates in accordance with the synchronization signal SYNC and executes a predetermined program.
Based on the output of the ADC-A/D corresponding to the phase difference output d5 corresponding to a predetermined time t in which the phase of the perpendicular lines P1 and P2 in the figure is advanced, the given digital signal is After determining which one applies, phase difference outputs d1 to d for each scanning line L1 to Ln are determined.
By adding the digital signals indicating n, the areas S1, S2 of each right-angled isosceles triangle T1, T2, T3, T4 are calculated.
, S3S4, and then (9) ,
Execute the calculation of equation (10), and calculate each horizontal and vertical deviation,
Detect {H and {V.

Also, after performing the above detection for the G video signal,
By controlling the multiplexer MPX to individually select R or B video signals and performing similar detection for each, R
, G, and B color image pickup tubes are determined, and thereby adjustment to match the image positions of the respective image pickup tubes can be easily performed.

However, it is also optional to adjust the image positions of the R and B image pickup tubes using the image position of the G image pickup tube as a reference, as in the conventional case.

In addition, a predetermined arithmetic circuit k and a control circuit may be configured and used by combining various logic circuits without using a small computer CPU, and each area S1, S2, S3, S
It is also possible to perform the detection in step 4 separately over multiple fields instead of in the same field, and it is also possible to provide the calculation results to the deflection circuit of each image pickup tube to automatically adjust the image position. can be freely modified.

As is clear from the above explanation, according to the present invention, the absolute image position deviation in the camera can be detected automatically and reliably, making camera adjustment easier and fully automated, making it suitable for cameras for various uses. A multi-dog effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of a test pattern, FIGS. 2 and 3 are diagrams showing the principle of the present invention, FIG. 4 is a block diagram showing an embodiment of the circuit structure, and FIG. It is a time chart which shows the waveform of each part in a figure. P... Pattern, L1-L4... Line segment, P1, P2... Perpendicular line, T, , T2, T
,...Right-angled isosceles triangle (triangle), S1, S
2, S3...Area, CAM...Camera, CCU...Camera control unit, BSG...
... Bar signal generator, MPX ... Multiplexer, PG ... Phase difference pulse generator, T/V
...TVC (time/voltage converter), SP...
...Sampling circuit, A/D...ADC
(analog-digital converter), CPU...
・Small electronic computer, DP...display section.

Claims (1)

[Scope of Claims] 1. A V-shaped pattern consisting of a left button and a right line segment having a predetermined angle θ to each other is simultaneously imaged by a television imaging system of a plurality of channels, and a specific one of the plurality of channels is When the graphic position of each line segment, which is formed by a video signal that is pressed on a channel, is a regular image position, the line segment intersects at the midpoint of each midpoint and has a length within the height of the V-shaped pattern. bar signals corresponding to the left and right perpendicular lines having The area of the upper right triangle formed by the bar signal corresponding to the perpendicular line is 81, and the area of the lower right triangle formed by the left line segment and the bar signal corresponding to the left perpendicular line is 81. 82, the area of the upper right triangle formed by the right line segment in the line segment figure and the bar signal corresponding to the right perpendicular line is 83, and the area of the right line segment and the right triangle is 83. When the area of the lower right triangle formed by the bar signal corresponding to the perpendicular line is 84, the normal image position of the specific channel defect and the specific channel defect obtained by the imaging are calculated by A method for detecting an amount of positional deviation of an image, characterized by determining an absolute horizontal deviation JHb and a vertical deviation, {V, from the position of each line segment figure formed by a video signal.