SU1427396A1 - Device for determining the position of object on an image - Google Patents

Description

The invention relates to the field of automation, in particular to a device for determining the position of an object in an image, and can be used in systems for recognizing and combining images of moving objects.

The purpose of the invention is to improve the accuracy and simplify the device.

Figure 1 presents the block diagram of the device; figure 2 is an example of a constructive implementation of the correlator; in FIG. 3 — the same, the unit for determining the coordinates j in FIG. 4 — the same, the temporal smoothing unit; fig. 3 - the same, control unit; FIGS. 6-11 are timing diagrams of control signals explaining signal operation.

The device (Fig. 1) contains the first memory block 1, the time smoothing block 2, the switch 3, the control block 4, the second memory block 5, the correlator 6, the coordinate detection block 7.

The correlator 6 (Fig. 2) contains the reader 8, the block 9 of the permanent memory, the adder 10 and the register 11.

The coordinate determining unit 7 (FIG. 3) contains the registers 12-14, the exchangers 15, 16, the gate 17 and the fixed memory block 18.

The temporal smoothing unit 2 (Fig. 4) contains constant memory units 19.20, multipliers 21, 22, adder 23, register 24, switch 25 and operational memory unit 26. The control unit 4 (Fig. 5) contains an OR circuit 27, a counter 28, a trigger 29, a permanent memory unit 30, an inverter 31, gates 32, 33, switches 34, 3.5, adders 36, 37, switches 38-40.

Figure 6-11 shows the timing diagrams of the control signals explaining the operation of the device.

When compiling time diagrams, the current image was considered to be 8x8 pixels, and the reference image was 4x4 pixels.

The proposed device works as follows.

The input of the current image memory block 1 receives the current television image signal. The processing period of this signal by the device can be divided into several stages (Fig.6).

1. Record the current television image in the memory block 1 of the current image 1.

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2. Determination of the coordinates of the object in the current television image in the correlator 6 and the unit 7 for determining the coordinates.

3. Interframe smoothing of the image of the object in block 2 of the temporal smoothing.

4. Update the reference image in memory block 5 of the reference image.

Consider the operation of the device at each of these stages.

The input of the memory block 1 receives the current television image signal. At the same time, the external control signal U6-5, which is necessary to synchronize the recording process in block 1 (Fig. 3), is input to the control unit. The first six bits of this signal are the address signals, and the seventh bit is the recording signal. An external control signal U6-6, which arrives simultaneously with the signal Ub-3, provides the passage of the signal U6-3 through the switches 38-40 of the control unit 4 to the control input of the memory unit 1. Operation: The devices at this stage are illustrated by the control signal diagram shown in FIG. 7.

In the second stage, the values of the current and reference images from blocks 1 and 5, respectively, are fed to the inputs of the correlator 6. In block 6, a differential correlation-extremal algorithm is implemented. The input of the subtractor 8 receives the values of the elements of the current and reference images. The subtractor 8 calculates the difference, the value of which is fed to the input of the memory block 9, with which the modulus of this difference is calculated. On accumulator 10 and register 11, there is a pooled accumulating adder, which is zeroed with a signal U4-1 before starting the calculation (FIG. 9). Signal Y4-2 is a write signal to register 11. The calculated value enters the coordinate determination unit 7, where the minimum value among all values is determined. The current value is fed to the input of the subtractor 15. At its second input, the current value of the minimum is stored in register 12. If the contents of register 12 are greater than the new value, then the sign of their difference, calculated on subtractor 15, will be equal to

l, which goes to valve 17 and allows the passage of the signal U5-2 to the inputs for writing registers 12 and 13. As a result, register 12 will write the new value of the current minimum, and in register 13 the values corresponding to this minimum and coming into block 7 from the block 4 controls (Y5-3 signal). At the end of the calculations, register 13 stores the values corresponding to the position of the object in the image. These values are transferred to control block 4, where the calculated values of the object coordinates are converted to another coordinate system, in which the coordinates (the object is equal to 0), are used when selecting the portion of the current image of the object entering the smoothing. is located at the center of the current frame. For this value, it goes to the subtractor 16, the second input of which receives the coordinates of the center of the current image, recorded in the fixed memory block 18. The calculated values are written in register 1 by the signal V5-4 and arrive at the output device.,

At the third stage, in block 2, the object image is smoothed. The smoothed image of an object is the sum of a large number of images of an object taken from a monotonously decreasing weight. Since each image of the object is taken from the corresponding frame with respect to the object coordinates found in it, the summation of the object images will lead to a decrease in the dispersion of the additive uncorrelated noise. Another positive consequence of this interframe smoothing is the smoothing of sampling and quantization errors, which also distort the image of the object. The input of block 2 receives the values of the elements of the section of the current frame, taken relative to the found coordinates of the object. The selection of the appropriate section of the current frame is provided by the control unit 4. The coordinates of the object in the current frame (signal U8) come from the coordinate determination unit 7 to the control unit 4. The values of the signal V8 pass through the switches 34, 35, to the adders 36, 37, to the second inputs

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The second is a DZ signal from block 30, a permanent memory. At the outputs of the adders, the address signals of the memory block of the current image are formed, which through the switches 38-40 enter block 1 (FIG. 10). At the multiplier 22, the value of the element of the current image is multiplied by the corresponding coefficient received from the fixed memory unit 20. On the accumulator 23, a total value is calculated, which is written to the register 24 by the signal U2-1 (FIG. 10). The calculated value through the switch 25 is fed to the input of the RAM 26 and is written there. In this case, the first 4 bits of the U2-3 signal are address signals, and the fifth bit is a write-read signal.

In the proposed device, the reference image is changed in each television frame, and the current value of the smoothed image is selected as the new standard. To do this, a smoothing of the smoothed image elements from block 2 of temporal smoothing and recording n: s into the memory block of the reference image is performed (Fig, 11). The first four bits of the Y2-3 and UZ signals are the signal, address addresses, and the fifth bit, the write-match signals. A characteristic feature of the interframe smoothing algorithm is that images of an object taken from different frames are included in a smoothed signal with different weights, and with the largest weights the images of the last frames are included in the smoothed signal.

The operation of the device at all stages of the calculation is synchronized by the control unit 4, as well as by the external synchronizing signals. The counter 28 of control unit 4 receives a clock sequence of rectangular pulses Ub-3. Signal V6-4 is an extra-normal device start signal. If the signal Ub-4 is 1, then the counter 28 is held in the zero state and the device does not work. If the signal Ub-4 is equal to O, then the device starts its work. The counter 28, under the influence of the clock pulses, generates the address of the block 30 of the permanent memory in which all control signals are recorded. The number of bits

 in block 30, the constant memory is equal to the number of control signals of the device, and the number of memory cells in each bit is determined by the period of operation of the entire device, divided by the duration of one calculation cycle,

In the first cycle of calculations, only steps 1, 3 and 4 are performed. During the first frame, the reference image is recorded in block 5 and the installation of the smoothed image in block 2 is initial. To ensure this mode of operation of the device, a U6-1 signal is received at its input (Figure 6), which sets the trigger 29 in a single state. Before starting the trigger 29 must be reset to zero by giving a signal. After the arrival of the signal Ub-1, the trigger 29 is in the single state until, at the end of the first frame from the permanent memory block 30, the signal D1 arrives, which triggers the trigger 29 to the zero state. In this state, trigger 29 is found during all subsequent calculations. The presence of the trigger 29 makes it possible to form the control signals U2-2 V7, which are necessary only in the first frame, and also block the passage of the signals V4, V5 to blocks 6, 7 of the device, which do not work during the first frame. The D4 signal from the trigger output 29 also goes to the permanent memory unit 30 as the address signal, ensuring that the first frame contains the corresponding control signals U5-3 and DZ used in steps 3 and 4. In subsequent frames, the D4 signal is O, and the signals U5-3 and DZ will take on different values than in the first frame, since they are read from another area of the fixed memory unit 30.

In the quality of the original reference image, both a specially formed image of the object and the current television image of the object can be selected. It enters the input of the device and is recorded in the memory block 1 of the current image. Since the reference image is smaller than the current television image, during the initial recording of the reference, the desired image of the object is recorded in the central part of the matrix of the current image memory block 1. Further from block 1

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the central part of the image recorded there containing the desired object is read. At the 3 rd stage, it is memorized in block 26 of the RAM of block 2 of temporal smoothing as the initial smoothed image. This is ensured by applying a signal U2-2 to the switch 25 and a signal U2-3 to the main memory unit 26 (Fig. 8). In step 4, the original reference image is recorded. For this, the central part of the image is read from block 1, which is stored in memory block 5 of the reference image (Fig. 8). Starting from the second frame, the device operates in the normal mode, having performed all the calculation steps (Fig. 6).

The proposed device allows to increase the accuracy of determining the coordinates of an object, since the reference image when changing it does not use the current image of the object, but a smoothed image in which the signal from the object is filtered from the additive noise that distorts it,

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A device for determining the position of an object in an image that contains the first memory block, whose information input is the information input of the device, the control input of the memory block is connected to the first output of the control unit, and the output C9 is connected to one information input the switch, another information input of which is connected to the output of the temporal smoothing unit, the control input of which is connected to the second output of the control unit, the second memory block, the information input of which is connected to the output of the switch The control input is connected to the third output of the control unit, and the output is connected to the first information input of the correlator, the output of which is connected to the information input of the coordinate determining unit, one output of which is connected to the information input of the control unit, in order to improve the accuracy and simplify the device, the output of the first memory block is connected to another information input of the correlator, the control input of which is connected to the fourth output of the control block and to the information input of the block smoothing, the fifth output of the control unit is connected to the control input of the switch, and the sixth output of the control unit under 968

The key is connected to the control input of the unit for determining the coordinates, the output of which is the information output of the device, while the start input of the control unit is the synchronizing input of the device.

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Claims (1)

Claim A device for determining the position of an object in the image, containing the first memory block, the information input of which is the information input of the device, the control input of the memory block is connected to the first output of the control unit, and the output is connected to one information input of the switch, the other information input of which is connected to the output of the block temporary smoothing, the control input of which is connected to the second output of the control unit, a second memory block, the information input of which is connected to the output of the switch, the branching input is connected to the third output of the control unit, and the output is connected to the first information input of the correlator, the output of which is connected to the information input of the coordinate determination unit, one output of which is connected to the information input of the control unit, characterized in that h + o, in order to increase the accuracy and to simplify the device, the output of the first memory block is connected to another information input of the correlator, the control input of which is connected to the fourth output of the control unit and to the information input of the temporary smoothing, the fifth output of the control unit is connected to the control input of the switch, $ • and the sixth output of the control unit is turnkey to the control input of the coordinate determination unit, the output of which is the information output of the device, while the start input of the control unit is the clock input of the device. Figure 2 Fig.Z Ub-g Ub-3 Ub-4 32> to UJue. 5 U5-3 1R. 2p ΞΣΗ 36 I " I B3 (1p * 3p) OT (4p4-Bp) U5-3 Зр, 6Р ^{1 1} I ' ¹ Ί 4 " .. • * 1 ..... V— Stages of Computing U6-1 (/ 6-4 IN 1 B4, U7, (/ 2-2 U6-6 Tj Tj τ " T, t ₂ t ₃ Ti —GT 1 ... .. R- * ----------1 μ ----------- ( ------------ 1 I /"frame 1, 1 2 ^and frame I 3 ^ύ κι d ----------- ¹ ------ »4 1 Fig 6 Lag. I