Method for computer-aided recording of interferogram image signal

FIELD: radio engineering, communication.

SUBSTANCE: method involves forced "long" and "short" accumulation of signal charges in adjacent frames (half-frames) in the photodetector of a television camera; generating a multiplex image signal at the output of the photodetector; generating, at the "video" output of the television camera, a multiplex television signal which is transmitted to the "video" input of a personal computer; the computer demultiplexing the video signal by delaying the input multiplex television signal by a frame (half-frame) and performing weighted summation of the forward and delayed video signals through remote sampling from the computer for that delayed component of the video signal with optimum duration of "short" exposure of the CCD array in the television camera.

EFFECT: high accuracy of recursive filtering by doing away with light splitting while facilitating adjustment of the degree of filtration by controlling the accumulation time of the delayed component of the output video signal.

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The present invention relates to television technician and can mainly be used in systems analysis of interferograms, in which the sensor signal applied to the matrix of charge-coupled devices (CCD).

The closest to the technical nature of the claimed invention should be considered as the method of forming the image signal of the interferogram [1], which consists in the fact that the light output from the interference pattern of the controlled object is divided in two directions and projected simultaneously on the first and second target (photodetecting section) specialized CCD image sensor, and illumination of the first target relative to the luminance of the second target set with the K-factor selected from the inequality 0<K<1, accumulate information charges on the target device (CCD) matrix with period frames (fields), in the interval of reverse vertical blanking carry the information charges of the cells of the second photodetecting section in the cell memory sections, and the information charges from the cells of the first photodetecting section in the vacant slot of the second photodetecting section, line-by-line transfer of the information charges of the memory sections in the output register in the interval of reverse horizontal, and in the interval forward stroke horizontal element per the wear of the information charges from the output register to the output unit of the CCD image sensor with simultaneous conversion of the charge into a voltage signal.

In the prototype solution directly in the sensor - CCD organization "human migration", in image signals in the charge form, by the method of recursive filtering of the video signal implement averaging of random fluctuations of the optical image of an object, caused for example by vibrations. The accumulation interval delayed component of the output image signal single recursive filter is fixed and equal to the interval of accumulation of the direct component of the signal at the output of the recursive filter. Adjusting the same degree of filtering is achieved by control of the magnitude of this component of the signal with a factor K, which is determined by the attenuation coefficient light to the first target device (CCD) matrix.

The disadvantage of the prototype [1] is the need to split the input light flow in two directions, which limits the accuracy of the operation of the recursive filter because of an error of the optical resumeware adjacent frames when accumulating information charges.

The objective of the invention is improving the accuracy of the recursive filter by not svetalana ensuring adjust the amount of filtering by controlling the dwell time delayed component video output.

The problem is solved in that Thu is in the claimed method computer Desk image signal interferogram namely, in the camera the light output from the interference pattern of the controlled object is projected on to a single target model of the CCD image sensor according to the present invention enforces the photodetector "long" and "short" accumulating information charges in adjacent frames (fields)form at the output of the photodetector multiplex image signal at the output of Video cameras form a multiplexed television signal, which is broadcast on the "Video" port of the computer to record the video signal in the computer memory, is carried out in the computer demultiplexing the video signal by performing a delay of the input multiplex television signal on a frame (field) and the implementation of the weighted summation of the direct and delayed video signals due to the remote select from your computer for this delayed component of the video signal optimum duration ' short ' exposure of the CCD image sensor in the camera.

Comparative analysis of the prototype [1] shows that the inventive method is distinguished by the implementation of signs (actions), namely:

- push the implementation of the CCD "long" and "short" accumulating information charges in adjacent frames (fields);

the formation of the output of the photodetector multiplex) is Ala, and the sensor output television signal (video cameras) - multiplexed television signal;

recording in the computer memory of the video signal generated by the camera;

- perform computer operations demuxing video signal that includes a delay of the input multiplex television signal and a weighted summation of the direct and delayed signals;

implementation of the duration of the "short" exposure of a sensor in the camera remotely from a computer.

As a result of implementation of such actions is provided not only improved accuracy of operation of the recursive filtering of the video signal, but also achieved highly desirable convenience of adjusting operations to optimize video for the recorded interferograms, as well as simplifying the design of the cameras.

The combination of known and new features not known from the prior art, therefore, the claimed method meets the requirement of novelty.

Technical result and the method of its achievement of the proposed solution meets the criterion of the presence of inventive step.

1 shows a structural diagram of a device that implements the inventive method; figure 2 shows a functional diagram of the device video Board installed, for example, freedom is hydrated PCI slot on the motherboard of a desktop computer; figure 3 - example of an electrical schematic of the switch in the composition of the cameras; figure 4 illustrates the process antiblooming flow in the CCD.

A device that implements the proposed method computer Desk image signal of the interferogram, see figure 1, contains on the transmission side the camera in position 1, comprising sequentially arranged and optically coupled lens 1-1 and sensor 1-2 television signal, and RS-flip-flop 1-3, selector 1-4 pulses of the counter-divider 1-5 and switch 1-6, at the receiving side computer in positions 2 and between the parties to the communication line at position 3, and the output Video sensor 1-2, which is the output of Video cameras connected to the input selector 1 to 4 clock pulses, the output of which connected to the clock input of the RS-flip-flop 1-3 and respectively to the input of the series-connected counter-divider 1-5 and switch 1-6, the first control input of which is connected to the first managing sensor input 1-2, connected to the direct output of the RS-flip-flop 1-3; the second control input sensor 1-2 is connected to the output switch 1-6, the second control input which, as with the S-input and R input of the RS-flip-flop 1-3 are the inputs of the "Management" of the camera, through which the cable conductor of the communication line 3 is connected to the corresponding outputs control signals to whom is utere 2; the output of the multiplex signal output from the Video camera is transmitted by individual cable conductors of the communication line 3 to the input Video computer 2.

As in the prototype [1], as a sensor 1-2 can be used, we offer Russian company "EMU" (Saint-Petersburg) open-frame camera VSI-746 [2], which is made on the basis of the CCD image sensor number of elements 582×752 and the size of the target diagonally ½ inch.

The CCD has the organization "line wrap", and its photodetection section is equipped with an electronic shutter that performs electronic sensitivity adjustment via control of the accumulation time of the charge carriers within the human period. In fact, the electronic shutter is a shutter antiblooming (stock) region GA, technologically made in the photodetecting section of the CCD image sensor, as shown in figure 4.

If the GA shutter is served the high level pulse bias, the potential barrier is removed, the shutter opens and photomeson eliminates the accumulation of photoelectrons. The charge carriers, do not linger in the potential wells under phase electrodes, for example under the tires FN when three-phase organization of migration flow into the deeper pits created by the potential of DA stock area, and then recombine in the substrate of the photodetector (see figb).

When the shutter GA m is tricy CCD serves the lower level of the pulse bias, closing it, there is the accumulation mode with a reduced inside a frame time of collection (see figa).

Feature sensor 1-2 in the proposed solution is the presence of the first and second control inputs.

For the device VSI-746 first managing input is the output 20 of the chip CXD2463R. If you want to enable automatic adjustment of the accumulation time (ARVN), you need to apply for this conclusion is a logical "0"to switch to the manual control mode the accumulation time is a logical "1" at TTL levels. The second control input of the device VSI-746 form conclusions 11, 12, 13 chips CXD2463R. For operation, ARVN these findings should "hang in the air, as they use a high-impedance resistive divider filed the corresponding potentials in the range of 1.3 to 3.5 Volts.

When you switch the eight values of fixed exposures in the range of from 10 μs to 10 MS, then they must be filed with the code combinations of zeros ("0") and units ("1")listed in the following table 1.

Note that the combination "000" defines the short duration of accumulation, and the combination of "111" is the longest. Install all of these code combinations are performed in the switch 1-6.

Possible electric circuit unit 1-6 (see figure 3) contains the first element "And" 1-6-1, the second element "And" 1-6-2, the third e is the COP "And" 1-6-3, the first element "OR" 1-6-4, the second element "OR" 1-6-5, the third element "OR" 1-6-6, the first switch 1-6-7, the second switch 1-6-8 and the third switch 1-6-9. The necessary code combination, which determines the exposure time of the photodetector camera 1 is installed on the computer 2 and translates into TTL levels on the communication line 3 to the second inputs of the elements "OR" 1-6-4, 1-6-5 and 1-6-6. The same binary code on the output switches 1-6-7, 1-6-8 and 1-6-9 is output to the unit 1-6. Note that in the original (initial) state unit 1-6 the input code is the logical combination "000".

If the enable inputs of the switches 1-6-7, 1-6-8 and 1-6-9 will be served a logic low, then regardless of the state at the inputs of the elements "And" 1-6-1, 1-6-2, 1-6-3 and code combinations on the input, the outputs of the switches are isolated from the inputs.

RS-trigger 1-3 is clocked trigger device RS-type with a high active level on the control input.

The selector 1-4 clock is used for separation of the composite video signal at the input of the synchronization signal receiver (BSC) with the subsequent formation of the output HR clock pulse (XI).

The counter-divider 1-5 is designed to perform frequency division pulse XI for two (from 50 Hz to 25 Hz) with progressive scan and respectively four (50 Gcdo of 12.5 Hz) with interlaced scanning video signal.

The device in figure 2 is a functional diagram of video Board installed into a free PCI slot on the motherboard of a desktop computer or a mini PCI slot laptop

When developing video Board should be made the main and essential conditions, namely: it must be consistent across channels I/o, control and power bus of the computer.

Input Video Board receives analog multiplex the video signal from the camera, and the Video card is formed recursively filtered digital video signal intended for recording on the hard disk of the computer image signal of interferogram.

In our example, the on-Board video with the direct participation of the components of the motherboard are the following signal operations:

- Analog-to-digital conversion (ADC) of the input video;

- Delayed digital video signal 20 MS organization in the camera progressive scan frame rate of 50 Hz or delay of 40 MS, if there is a standard interlaced;

Weighted summation of the direct and delayed signals;

- Formation for camera control three-digit binary signal Code "exposure";

- Formation for camera control single pulse "start" and "Stop". All commands on the I control the camera and to implement a weighted summation of the signals are performed with a computer keyboard and/or computer mouse.

It should be noted that the operation delay of the digital video signal and the operation of the weighted summation of the direct and the delayed digital video signal are performed on-Board video when from a computer to a television camera filed the "start"command. In the initial state or when returning the camera to its original state by the command "Stop" with computer operation delay and summation on Board video is blocked, and the output signal of the Video card becomes the video camera, receiving only analog-to-digital conversion.

The way computer Desk image signal interferogram is performed as follows. We will use a structural diagram of the device depicted in figure 1.

Suppose situated in the field of view of camera 1 interventiona picture of the object is perfectly static position without random fluctuations due to vibration and other regular mechanical effects of low frequency. Thus let us assume that the external control for the camera is missing, i.e. on all inputs "Management" are logic "0". The camera operates in progressive mode, and the luminance of the object allows to set the accumulation time of the CCD image sensor providing the signal with the maximum respect of the m/n ratio.

Then an automatic adjustment of the accumulation time (ARVN) of the photodetector in the sensor 1-2 set the maximum value of the current exposure, i.e. the duration of the accumulation of charges will be 10000 μs. If the selector switch 1-4 clock selects the output of the personnel pulses with a period T_nand the counter-divider 1-5 - divides the input frequency by two, forming the output square wave with a period of T_∂1/=2T_n.

Let the object of control occurs low-frequency mechanical impact. Then in the generated video signal inevitably appears a blur, and observed on the screen of the monitor of the computer 2 image noticeably deteriorates its quality by reducing the signal/noise.

To complete the task of the invention to the S-input of the RS-flip-flop 1-3 cameras from a computer is a pulse of positive polarity. At the time of coincidence of the high level of the pulse with a high level of HR clock pulses at its clock input the trigger condition changes. To direct the output of the trigger 1-3 is set to a logical signal "1".

The latter is fed to the first control input unit 1-6 and the first control input sensor 1-2. Therefore, the scheme was ARVN sensor 1-2 is disabled, and its second control input is connected to the output unit 1-6.

Note that regardless of this switching selector-4 clock continues to select the output of the personnel pulses, and the output of the counter-divider 1-5 pulses with a period of T_∂.

When connecting the second control input sensor 1-2 to the output unit 1-6 on this input for the duration of the low level of the square wave pulses from the output of the block 1-5 set the logical combination "000", ensuring continued staffing of charge accumulation in the CCD sensor, is equal to 10 μs -$$T_n^{m\mathrm{and}n}$$(see table 1). When output block 1-5 will be served with a high level of square wave pulses, then at this time the second control input sensor 1-2 set the logical combination "111", guaranteeing the accumulation time of the CCD image sensor 10000 MKS -$$T_n^{m\mathrm{and}K\mathrm{with\; a}}$$(see table 1).

This allows the sensor 1-2, and, consequently, the television camera 1, generates a multiplexed image signal adjacent frames which are "long" and "short" signals in accordance with the mode of accumulation of charges in the CCD sensor.

This multiplex signal is supplied through the communication line 3 to the input Video video Board installed in an expansion slot on the motherboard of the computer 2. Because the lock is removed, fee videos implements otlojennye it functions ADC, delay and weighted summation.

Compared with the prototype of a weighted summation of the signals in the proposed decision is not due to a decrease of the amplitude of the delayed component of the image signal accumulated in the current frame (frame), and by selecting for this component of the shortened duration of exposure of photoparade (in our example equal to$$T_n^{m\mathrm{and}n}$$).

Assume that the camera operates in interlaced mode. Then at the output of the selector 1-4 clock pulses with a period of half-frames T_n. The counter-divider 1-5 divides the input frequency by four, i.e., the period of output pulses will be: T_∂2=4T_n. During the high-level activities of the meander sensor 1-2 is carried out not one but two cycle exposure with long charge accumulation in$$T_n^{m\mathrm{and}K\mathrm{with\; a}}$$for each. Similarly, during the low level of new meander in the sensor 1-2 will be made not one, but two cycle exposure with short charge accumulation in$$T_{m\mathrm{and}n}^{}$$. In the on-Board video is a digital delay signal into two fields, i.e. for the duration of two T_n.

In other respects the operation of the device that implements the claimed method, will not differ from its operation in the progressive mode.

If necessary, return the camera to its original mode shall file from your computer pulse of positive polarity to the input R input of the RS-flip-flop 1-3. Then the state of the trigger will change to direct its output will be a logical signal "0", and the sensor 1-2 is restored the functioning of the scheme ARVN.

At the same time for the video Board in the computer will be restored lock functions of the video signal delay and weighted summation. Therefore, the output Video of this fee will be transmitted only digitized standard television signal sensor 1-2.

Compared with the prototype [1], the proposed method computer Desk image signal interferogram eliminates the need for splitting the input light flow in two directions with a view to their projection on two photomechanic specialized CCD. So essentially eliminated the possible inaccuracy of the recursive filtering the video signal is because of an error of the optical resumeware adjacent frames when accumulating information charges. At the same time provides improved productivity and simplify the design of the cameras.

Currently, all the blocks of the block diagram of a device that implements the proposed method, developed or may be developed by the domestic industry. Therefore, we must assume the present invention corresponding to the requirement of industrial application.

SOURCES of INFORMATION

1. Patent No. 2068624 of the Russian Federation. IPC H04N 5/225, 7/18. The signal image of the interferogram / Vmmall // B. I. - 1996. No. 30.

2. Television camera company "EMU", catalogue, 2005

3. Digital and analog integrated circuits: Handbook / Sviatoslavsky, Lignosellus, Vigolana and others - M.: Radio and communication, 1990.

4. Falkenberry L. the Use of operational amplifiers and linear IC: Translation from English. - M.: Mir, 1985.

The way computer Desk image interferogram consists in the fact that in a television camera (the camera) luminous flux from the interference images of the test object is projected on to a single target matrix of charge-coupled devices (CCD), characterized in that it enforces the photodetector "long" and "short" accumulating information charges in adjacent frames (fields)form at the output of the photodetector multiplex image signal is, form at the output of video cameras multiplex television signal, which is broadcast on the "video" port of the computer is carried out in the computer demultiplexing the video signal by performing it delays the input multiplex television signal on a frame (field) and the implementation of the weighted summation of the direct and delayed signals due to the remote select from your computer for this delayed component of the video signal optimum duration ' short ' exposure of the CCD image sensor in the camera.