Image information output apparatus

An image information output apparatus has a position specifying section for generating a cursor line signal intended to cause two vertical cursor lines to be displayed superposed upon a picture image corresponding to an image signal of an ITV camera, and an integrator for integrating image signal components corresponding to a region between the cursor lines. The integration output signal of the integrator is converted into a measured line picture image signal, which is displayed on a monitor television device together with the picked-up image.

BACKGROUND OF THE INVENTION 
The present invention relates to an image information output apparatus, and 
more particularly to an image information output apparatus designed to 
output the luminance data of a specified region of a picked-up image so as 
to be superposed upon this picked-up image. 
In the field of image information output apparatuses, a video measuring 
system has recently been developed. This video measuring system is used to 
set a single vertical luminance line at a given position on the image 
screen and to pickup image data on the vertical luminance line, thereby 
measuring the width or darkness and lightness of the surface of an object 
to be photographed. However, the prior art video measuring system is 
constructed such that the image data is picked up with respect to the 
single vertical line. Therefore, when a video camera is defective and 
noise is mixed into the image information, the image data of an image 
portion corresponding to such noise components is mixed into the image; 
errors thus occur in the signal processing, and a precise measurement 
cannot be made. 
To cope with these problems the position of the vertical line is moved 
stepwise in the horizontal direction, and luminance data is extracted at a 
plurality of vertical positions, and an average value of those data is 
determined by, for example, a data processor which permits this value to 
be displayed on a monitor. However, where such countermeasures are taken, 
a microprocessor and a memory of large capacity are required to process 
the data corresponding to the plurality of vertical positions, resulting 
in a large and complicated video measuring apparatus as well as in an 
increased manufacturing cost. 
SUMMARY OF THE INVENTION 
Accordingly, the object of the present invention is to provide an image 
information output apparatus which reduces the effect of noise components, 
has a simple circuit construction, and which makes it possible to obtain 
measured image information of high quality. 
According to the invention, at least two vertical lines are set on an image 
screen, image information components of the image region between those 
vertical lines are integrated for each horizontal line, the integrated 
value is compared with a horizontal scanning signal (sawtooth signal) and 
is thereby converted into a position signal on the horizontal scanning 
line. The conversion signal thus obtained is used to measure the darkness 
and lightness of the surface of an object to be photographed in the form 
of line data corresponding to a line perpendicular to the horizontal line 
of an image screen.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIG. 1, the image signal output terminal of an industrial 
television (ITV) camera 11 is connected to an input terminal of a mixer 14 
through an amplifier 13 in an image signal processing circuit 12. The 
vertical and horizontal synchronizing signal output terminal of a 
synchronizing signal generator 15 are connected to the vertical and 
horizontal synchronizing signal input terminals of the industrical 
television camera. The horizontal synchronizing signal output terminal of 
the generator 15 is connected to the synchronizing signal input terminal 
of a sawtooth signal generator 16. The output terminal of the sawtooth 
signal generator 16 is connected to respective input terminals of 
comparators 17 and 18. The horizontal synchronizing pulse output terminals 
of the synchronizing signal generator 15 are connected to the control 
input terminals of an integrator 19 and a sample-and-hold circuit 20, 
respectively. The output terminal of the amplifier 13 is connected to the 
input terminal of the integrator 19. A range signal generator 21 is also 
connected to this integrator 19. The output terminal of the integrator 19 
is connected to the input terminal of the sample-and-hold circuit 20. The 
output terminal of the sample-and-hold circuit 20 is connected to another 
input terminal of the comparator 18. The reference input terminals of the 
comparator 17 are connected to a potentiometer circuit 22, while the 
output terminals thereof are connected to the mixer 14 as well as to the 
range signal generator 21. The reference input terminals of the comparator 
17 are also connected to a CPU 23. 
The mixer 14, comparator 18 and sample-and-hold circuit 20 constitute a 
luminance data output section 24. Further, the comparator 17 and 
potentiometer circuit 22 constitute a position-specifying section 25. The 
mixer 14 of the luminance data output section 24 has its output terminal 
connected to a monitor television device 26. 
The operation of the above-mentioned circuit will now be described in 
connection with the time chart of FIG. 2. 
When a power source is turned on and a start switch is actuated, the 
synchronizing signal generator 15 supplies vertical and horizontal 
synchronizing signals to the ITV camera 11. When, at this time, an actual 
image including an object to be examined, for example, an object whose 
width must be measured, is photographed by the ITV camera 11, the camera 
11 produces an image signal VS. The image signal VS is amplified by the 
amplifier 13 and is then supplied to the mixer 14 and to the integrator 
19. 
The sawtooth signal generator 16 generates a sawtooth signal SV in 
synchronization with the horizontal synchronizing signal HD. This sawtooth 
signal SV is supplied to the comparators 17 and 18. The comparator 17 
compares the sawtooth signal SV with cursor position designation voltage 
signals V1, V2 and, when the voltage of the former becomes equal to the 
latter, produces cursor designation pulses C1 and C2. When the cursor 
designation pulses C1 and C2 are supplied to the range signal generator 
21, this generator 21 produces a pulse signal WP having a pulse width 
corresponding to a period between the pulses C1 and C2. When the pulse 
signal WP is supplied to the integrator 19, the integrator 19 integrates 
the image signal VS during the period corresponding to the pulse width of 
the pulse signal WP and produces an integration signal IS. The integrator 
19 is reset by a synchronizing pulse HDP. The synchronizing pulse HDP is 
generated in response to a trailing edge of the synchronizing signal HD. 
In contrast, a synchronizing pulse HDN is generated in response to a 
leading edge of the synchronizing signal HD. 
When the integration output IS of the integrator 19 is supplied to the 
sample-and-hold circuit 20, this circuit samples and holds the integration 
output IS in response to the synchronizing pulse HDN up to the begining of 
the next horizontal scanning period and produces a sample-and-hold signal 
SIS. The signal levels Sn-1', Sn' and Sn+1' of the sample-and-hold signal 
SIS correspond, respectively, to the levels prepared by subjecting the 
signal levels Sn-1, Sn and Sn+1 of the integration output IS to a 
specified voltage reduction. When the output signal SIS of the 
sample-and-hold circuit 20 is supplied to the comparator 18, this signal 
SIS is compared with the sawtooth signal SV by the comparator 18. When the 
level of the sawtooth signal SV becomes equal to that of the signal SIS, 
the comparator 18 generates a pulse signal B. 
The signals B, C1 and C2 are supplied to the mixer 14 and combined with the 
image signal VS. The mixer 14 generates an output signal MVS, which is 
supplied to the monitor television device 26. In this case, as shown in 
FIG. 3, the black spots ID, KD1 and KD2, which correspond to pulses B, C1 
and C2, are displayed on one horizontal scanning line. When the sawtooth 
signal SV corresponding to the next horizontal scanning line is supplied 
to the comparators 17 and 18, these black spots ID, KD1 and KD2 are then 
displayed on this next horizontal scanning line. If the device 26 is of an 
interlace system, the black spots are displayed on every second horizontal 
scanning line, and vertical cursor lines KL1 and KL2 and a measured line 
IL, which corresponds to the integrated value of luminance data 
representing the luminance of the region between lines KL1 and KL2, are 
also displayed, as shown in FIG. 4. When the cursor lines KL1 and KL2 on 
the device 26 are viewed and it is desired to change their positions, the 
potentiometers P1 and P2 of the potentiometer circuit 22 are adjusted. The 
cursor position designation voltages V1 and V2 are thus varied, thereby 
moving the lines KL1 and KL2, respectively, to their desired positions. 
The difference between the voltages V1 and V2 corresponds to a distance 
between the cursor lines KL1 and KL2. The integrator 19 integrates the 
luminance data, and the value obtained by this integration is displayed as 
the measured line IL on the display screen. Even when an image of noise 
components is mixed between the lines KL1 and KL2, the noise components do 
not largely affect the value of the output from the integrator 19. The 
measured line IL is therefore displayed as a line substantially unaffected 
by the noise. 
When the data of the measured line IL, i.e., the output signal SIS of the 
circuit 20, is supplied to the CPU 23, the CPU 23 calculates the width of 
the object. In calculating the width of the object, as shown in FIG. 5, a 
measured line image signal VSIS obtained during the period between two 
adjacent vertical sync pulses VD is binary coded, using the threshold 
voltage TH as the reference. The period of time, which corresponds to the 
width W, is measured by counting clock pulses. The count CNT thus obtained 
is multiplied by an optical coefficient k. The width W is thus given as 
follows: 
EQU W=k.multidot.CNT 
The voltages V1 and V2 from the potentiometer circuit 22 are applied to the 
CPU 23. From these voltages V1 and V2 the CPU 23 determines the positions 
of the cursor lines KL1 and KL2 on the display screen. If the image of the 
object is on either the left or right section of the display screen, the 
CPU 23 determines whether or not the cursor lines KL1 and KL2 overlap the 
image of the object. 
The difference between the voltages V1 and V2 corresponds to the gain of 
the signal VSIS. Hence, the threshold voltage TH is changed according to 
the difference between the voltages V1 and V2, thereby keeping the ratio 
of the voltage TH to the signal VSIS constant. Since this ratio remains 
constant, the width of the object can be accurately measured, and is not 
affected by the movement of the cursor lines KL1 and KL2 on the display 
screen. PG,10 
As mentioned above, according to the invention, the luminance data of the 
image region defined between the two vertical cursor lines KL1 and KL2 is 
integrated and the resultant integrated value is displayed as measured 
data, and therefore, even if noise components are mixed into the image, 
the measured data is almost unaffected by such noise components, with the 
result that high quality measured data is obtained. In addition, the 
signal processing can be effected for a period of time substantially equal 
to that required for the scanning of the ITV camera, which is advantageous 
in using the apparatus. Further, since, according to the invention, the 
integration and signal generation can be effected by relatively simple 
circuits, the resultant image display control apparatus becomes not only 
simpler in construction than the prior art apparatus, but also smaller and 
cheaper to manufacture. 
In the above-mentioned embodiment, the vertical cursor lines KL1 and KL2 
and the measure data line IL are displayed as black lines. However, these 
lines may be displayed as white lines. In this case, positive pulses are 
combined with the image signal as the pulses B, C1 and C2. Further, 
vertical cursor lines KL1 and KL2 may be displayed as black lines while 
the measured data line IL is displayed as a white line. When the display 
is made in such a manner, it becomes easy to visually discriminate the 
data. Where such visual data recognition is not necessary, any of the 
pulses B, C1 and C2 may be excluded from the image signal. Further, the 
photographing device is not limited to an ITV camera, but may comprise, 
for example, a sensor using a two-dimensional solid image pickup element. 
Various modifications may be made in the scanning system as well as in the 
construction of the monitor.