JPH05313647A - Real time image profile generating device - Google Patents

Abstract

PURPOSE:To monitor variation in luminance distribution almost in real time and to decrease the circuit scale and lower the price. CONSTITUTION:An image signal is digitized by an A/D converter 14. A synchronization separating circuit 15, a line address generator 16, a comparator 17, and a memory control circuit 18 store image data of a line that a user specifies in a one-line memory 19. This image data are converted into luminance distribution data by using a look-up table 20. The luminance distribution data are compared by a comparator 21 with a line address and outputted as profile pulses when agreeing with the line address, and the pulses are converted by a D/A converter 22 into analog display pulses, which are put together with the original image signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a real-time image profile generator for displaying the luminance distribution state of image signals.

[0002]

2. Description of the Related Art There is an apparatus for displaying an intensity distribution of an image signal of an object to be measured (for example, a spot of a laser beam, a knot of a wooden board, etc.) by a television camera. A conventional device of this type converts an image signal into an analog signal, temporarily stores one frame or one field of the image data in an image memory, and performs image processing by software by a microprocessor to show a luminance distribution. A method of creating image data for display, storing the image data in a display memory, and displaying the image data is used. However, according to this method, when the luminance distribution of the object to be measured changes sequentially, the situation cannot be observed. Further, since expensive circuit elements such as a frame memory and a microprocessor are used, the apparatus itself becomes expensive, and the scale of hardware increases.

[0003]

As described above, according to the conventional image profile generator, it is impossible to monitor the change in the luminance distribution in real time. There is also a problem that the device is large and expensive.

Therefore, it is an object of the present invention to provide a real-time image profile generator capable of monitoring changes in luminance distribution almost in real time and having a small circuit size and low cost.

[0005]

SUMMARY OF THE INVENTION The present invention comprises address generating means for generating an on-screen address of an input image signal,
The address from the address generating means is compared with the designated address, and the data fetching means for fetching the data on the line on the screen and the output data of the data fetching means are data-converted in accordance with a predetermined contrast relation to correspond to the screen area Profile signal that outputs a pulse for display when a lookup table that outputs the above-described luminance distribution data and the luminance distribution data from the lookup table and the address are compared directly or indirectly and they match The output means is provided.

[0006]

By the above means, the profile signal pulse is generated by comparing the look-up table and its output with the address, and it becomes easy to display the profile signal in real time.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. FIG. 1A shows an example of a horizontal profile generator, and FIG. 1B shows an example of a vertical profile generator. See also FIG.
(A) is an example of a display image by a horizontal profile generator,
FIG. 1B shows an example of a display image by the vertical profile generator.

An image signal of the object to be measured is input to the input terminal 11, and is input to the adder 13 via the time adjusting delay device 12. The adder 13 adds the profile signals described below.

The image signal from the input terminal 31 is supplied to the analog-digital (A / D) converter 14 and the sync separation circuit 15. The digital image signal output from the A / D converter 14 is supplied to a 1-line memory 19 capable of storing data for 1 horizontal period. Which line is stored is determined by the memory control described below. The sync signal separated by the sync separation circuit 15 is input to the vertical line address generator 16. The vertical line address output from the vertical line address generator 16 is supplied to the comparators 17 and 21. The comparator 17 is
It is possible to determine which line is to be stored in the 1-line memory 19. That is, the designated address of the vertical line is input to the comparator 17 via the terminal P. This designated address is created and supplied by an operation unit (not shown) by a user's operation. Comparator 17
When the coincidence signal (timing signal) is obtained from the memory control circuit 18, the memory control circuit 18 gives a write and read address for one line of image data to the one line memory 19.

The image data output from the 1-line memory 19 is input to the look-up table 20. The lookup table 20 obtains output data of a luminance distribution according to the luminance level of the input image data, performs data conversion, creates luminance distribution data over one screen, and outputs the luminance distribution data. This brightness distribution data is input to the comparator 21. The comparator 21 compares the brightness distribution data with the vertical address, and outputs a pulse when they match. This pulse is added to the adder 13 via the D / A converter 22.

The position of the image data of the horizontal line to be the luminance distribution detection target can be known from the pulse timing obtained from the comparator 17, and when the timing pulse is obtained, the measurement scanning line display data is changed to the horizontal cursor. The data is output from a data generator (not shown) and supplied to the adder 13.

Therefore, the types of image signals obtained at the output terminal 23 are roughly classified into A. The captured image signal itself,
B. A horizontal profile pulse signal output from the D / A converter 22; There is a horizontal cursor indicating the position of the measurement scan line.

FIG. 2A shows an example in which an image signal from the horizontal profile generator is displayed. For example, it is assumed that the image signal is a signal obtained by capturing an image of a light source that shines at one point in the dark. Further, it is assumed that the light source is captured almost at the center of the screen. Also, the horizontal cursor is aligned with the vertical center. In this situation, the image data at the position indicated by the horizontal cursor is 1
It is taken into the line memory 19 and converted into data by the look-up table 20.

When the brightness is low, the look-up table 20 generates a large value of data and outputs it to each scanning line at the horizontal scanning timing of the input brightness signal. The data of a low value is output according to the horizontal scanning timing of the input luminance signal. Therefore, the data of the waveform as shown in FIG. 2C is output. When this waveform data is input to the comparator 21, it is compared with the vertical address. In the comparator 21, the lookup table 2
When the output from 0 coincides with the vertical address, a pulse is obtained, so that the horizontal profile pulse signal as shown in FIG. 2A is finally displayed on the screen. It is in the next field that this waveform is completely completed and displayed. This is because, in the example of the figure, the signal for creating the luminance distribution is taken in at the position of the vertical address n / 2. The data conversion characteristics and the data output timing characteristics of the lookup table 20 are as shown in FIGS. 2 (D) and 2 (E). That is, when the input luminance signal level is high,
Output data having a small value is generated, and when the input luminance signal level is small, output data having a large value is generated. The horizontal scanning direction output timing of the generated data corresponds to the pixel horizontal scanning timing of the input luminance signal.

According to the horizontal profile generator configured and operating as described above, the image data for one field or one frame is temporarily stored in the memory as in the prior art, and this data is image-processed to display the luminance distribution. It is possible to display the luminance distribution of the image data input one after another in almost real time, as compared with a device of a method in which the data is created and stored in the display image memory for display. Then, by moving the horizontal cursor, the luminance distribution at that position (vertical position) can be viewed. The above embodiment is an example in which the luminance distribution in the horizontal direction can be seen, but in order to see the luminance distribution in the vertical direction,
It can be realized by the same principle.

FIG. 1B shows another embodiment of the present invention, which is a vertical profile generator. The configuration is similar to that of FIG. An image signal of the object to be measured is input to the input terminal 31, and is input to the adder 33 via the delay device 32 for time adjustment. The adder 33 adds the profile signals.

The image signal from the input terminal 31 is supplied to an analog / digital (A / D) converter 34 and a sync separation circuit 35. The digital image signal output from the A / D converter 34 is supplied to a vertical line memory 39 capable of storing data for one vertical line in which pixels are arranged in the vertical direction. The sync signal separated by the sync separation circuit 35 is input to the horizontal pixel address generator 36. The horizontal address of the horizontal line output from the horizontal pixel address generator 36 is supplied to the comparator 37 and the look-up table 44. The comparator 37 can determine which position (horizontal position) is to be stored in the vertical line memory 39. That is, the horizontal addressing signal is input to the comparator 37 via the terminal P. This designation signal is created and supplied by an operation unit (not shown) by a user operation. When the coincidence signal (timing signal) is obtained from the comparator 37, the memory control circuit 38 gives the vertical line memory 39 a write and read address for one line of image data in the vertical direction.

The image data output from the vertical line memory 39 is input to the lookup table 40. The lookup table 40 obtains output data of a luminance distribution according to the luminance level of the input image data, performs data conversion, creates luminance distribution data for one screen, and outputs the luminance distribution data. This brightness distribution data is input to the comparator 41. The comparator 41 compares the brightness distribution data with the data from the look-up table 44, and outputs a pulse when they match. This pulse is added as a vertical profile signal to the adder 33 via the D / A converter 42.

The position of the image data of the vertical line for which the luminance distribution is detected can be known from the pulse timing obtained from the comparator 37. When the timing pulse is obtained, the measurement scanning line display data is changed to the vertical cursor. The data is output from a data generator (not shown) and supplied to the adder 33.

The operating principle is the same as in the previous embodiment,
The screen display state is shown in Fig. 2 for the same DUT as before.
As shown in FIG. Look-up table 4
Reference numeral 4 is for matching the range with the data output from the lookup table 40, and need not be provided in particular.

In the above-described embodiment, the profile signal and the input video signal are also displayed at the same time in accordance with the cursor, but it is possible to display only the input video signal or excluding the video signal as required. Thus, a changeover switch may be provided. Furthermore, in the above embodiment, the luminance distribution on the line in the vertical direction or the horizontal direction is detected, but the luminance distribution on the line in the diagonal direction on the screen can also be displayed by slightly changing the memory control circuit. Is easy to do. It is also possible to change the line for checking the luminance distribution by switching the memory control circuit.

Although the above embodiment has been described as an apparatus for displaying the state of the brightness distribution, it is possible to easily realize the display of the color distribution or the display of the brightness distribution by color. In the case of displaying the color distribution, the target color signal (R, G, B) may be selected and input as the input image signal. In the case of luminance distribution display by color, the R, G, B signals may be input in a time-division manner, or the circuit configuration shown in the figure may be prepared in parallel for each primary color signal for the final output. May be obtained by combining.

Further, in the above example, the input analog signal and the D / A converted profile signal are added in an analog manner. However, the connection as shown by the dotted line in FIG. The output of the adder 13 is D / A
It may be configured to be converted.

[0025]

As described above, according to the present invention,
It is possible to monitor changes in the brightness distribution almost in real time, and the circuit size is small, which can be realized at low cost.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing two embodiments of the present invention.

2A and 2B are an image display explanatory diagram and a characteristic example shown for explaining the operation and function of the circuit shown in FIG.

[Explanation of symbols]

14, 34 ... A / D converter, 15, 35 ... Sync separation circuit, 16 ... Vertical line address generator, 17, 21, 3
7, 41 ... Comparator, 18, 38 ... Memory control circuit, 19 ... 1 line memory, 20, 40, 44 ... Look-up table, 22, 42 ... D / A converter, 13, 3
3 ... Adder, 39 ... Vertical line memory.

Claims (5)

[Claims] 1. An address generating means for generating an on-screen address of an input image signal, a data fetching means for fetching data on a line on a screen by comparing an address from the address generating means with a designated address. A look-up table for converting the output data of the data fetching means into data according to a predetermined contrast relationship and outputting the brightness distribution data corresponding to the screen area; and a direct or direct connection between the brightness distribution data from the look-up table and the address. A real-time image profile generator comprising: a profile signal output means for outputting a pulse for display when an indirect comparison is made and coincidence is obtained. 2. The real-time image profile generator according to claim 1, wherein the address generator is a vertical line address generator. 3. The real-time image profile generator according to claim 1, wherein the address generator is a horizontal pixel address generator. 4. The real-time image profile generator according to claim 1, wherein the pulse for display is combined with the input image signal. 5. The real-time image profile generator according to claim 1, further comprising means for outputting cursor data at the specified address and synthesizing the cursor data with the input image signal.