CZ563289A3 - optical-fiber processor of hough linear transformation - Google Patents

Abstract

The subject of the invention relates to the field of electronics or. optoelectronics fiber optics. It solves a technical problem implementation of Specialized Problem Oriented Fast Optical Fiber Signal Processor (2) Hough Line Transformation, hereinafter referred to as "HTP". In the process calculation of spectral coefficients HTP optical fiber the signal processor (2) is connected to the electronic the input unit (1) and the electronic input processor (3) HTP. The optical fiber signal processor (2) is realized by optical circuit (4) of single-mode fibers and consists of a special optical fiber recirculation pamati (12) and the arithmetic portion formed from T cascade connected arithmetic units (15). Every arithmetic the unit (15) is composed of two full-threaded Mach-Zehnders interferometers (26, 27) formed from two 3 dB optical fiber taps (28, 29, 30.31) taking in one of the arms of each Macho-Zehnder the interferometer (26, 27) is a piezoelectric modulator connected (32, 33). Mach-Zehnder outputs interferometers (26, 27) are attached to the full-fiber optical signal merger (36).

Description

The invention relates to the technical implementation of a very fast optical fiber processor for the calculation of the spectral coefficients of the Hough transformation of a line of a scanned image.

The Hough Line Transform (HT.P) has found and finds increasingly widespread applications in various areas of digital imaging. In particular, it is the universality of its applications to detect various objects, their movement, texture measurement, etc. 7, its resistance to image noise, incomplete and overlapping objects, etc.

Previously known HTP processors perform the calculation of spectral coefficients of HTP in electric, resp. in the optical region. The disadvantage of HTP electronic digital processors is the necessity to realize a large number of multiplications and additions, which in addition to the low rate of spectral coefficient calculation also increases the complexity of the device. Some progress in this area is the replacement of multiplication by reading from the table of predicted values, which disadvantage is the need for large monuments with greater accuracy. Another possibility is parallelization of the calculation, which results in high complexity and cost of the equipment. The previously known optical analogue HTP processors make it possible to accelerate the calculation of the spectral coefficients of HTPs, but their disadvantage is that they require particularly high

- r (and hence expensive) optical elements. Due to the use of volumetric optics elements in these processors, these are sensitive to environmental influences.

These drawbacks are overcome by the object of the invention, which is to use an optical fiber signal processor when calculating the spectral coefficients ~ HTP. This processor consists of an optical circuit of suitable interconnected single-mode optical fibers, a processor for adjusting the parameters of this circuit and electro-optical and optoelectronic converters at the input, respectively. optical fiber processor output. The advantage of using this HTP processor results in the speed of calculating the spectral coefficients of HTP (the signal propagates in the processor at the speed of light propagation in the single mode fiber used), as well as a number of secondary advantages resulting from the use of fiber optics. three-dimensional structure, immunity to electromagnetic interference, environmental influences, etc. Another advantage of the present invention resides in a uniform technological basis of optical fiber signal processor elements. All are based on optical fiber sections and suitable directional taps realized by optical fiber welding and its modular structure. the arithmetic part of the processor consists of T identical stages, which makes it possible to simplify production and increase its seriality.

In the accompanying drawings, Fig. 1 shows a circuit diagram of an HTP processor; Fig. 2 shows a circuit diagram of an HTP processor;

3 shows the optical fiber signal processor's single-mode optical circuit, and FIG. 3 shows the optical fiber arithmetic unit wiring diagram.

In the following, the technical implementation of a particular embodiment of the invention and its functional parts will be explained by means of the drawing. HTP is essentially a representation of the signal area (or image space) in the spectral area (or parameter space), respectively. In this representation, the normal parameterization of the line ^ (^, ^) = x cos ^ + y sin ^ - £, 2 (x, y) R R (signal area) and age2 is the most commonly used. , R) 6 R ^z (spectral region). In practice, in particular, a discrete implementation ΚΓΡ is used, bounded by a discrete space of images. {(x _v yj). i - i - 1 ..... m} with the discretization step Ax and Ay selected. If the coordinates (X1, yj) of the arbitrary pixel respectively. the edge element in the image holds ^x i> ^{= x} max

I y · II y ^1} j ^{1 1J} max (2) then parameters £ and # are from the delimited area max (3)

2: _v ^{+ and} P ^re suitable chosen discretization max max where ^ max = 5 step A ^ and áváme we get bounded discrete spectral region HTP JI = {(£ ,, $ ^), r = 1,. .., R t = 1,. . . ,i.e. Relation (1) determining the transformation between? and JI can then be written in the form

Jr = _X1 cos ^ t ₊ y. sin # _t = k, ^ ₊ k _2ty (4) where we denote k _{] t} = cos if _2t = sin ^. We calculate the spectral coefficients HTP S ^ (á *) in a discrete form cyclically so that for each non-zero op, resp. edge element (x ^ y ^) and for each &, the calculation according to (- ^) is performed and so called ^ voting) is done in the spectral region, ie

^S 5%? ' ^{+ v (x} i'yj ⁾ using different weights of voices í-CXi.yý g (x _i5 yj) kCxpyp (6)

- constant, f (X |, yj) - brightness value op, g (X |, yj) - edge gradient size a k (x ^, y ^) - edge covering size, etc.

If the number of non-zero ops resp. the number of edge elements in the picture P and the discretization of the angle α is on the T part, then HTP requires the calculation of the relationship (4) PT times, i.e. 2PT multiplication and PT additions need to be performed without considering rotation in relation to (6). For carrying out these calculations, an optical fiber signal processor 2 may be used (within the meaning of the invention).

Fig. 1 is a circuit diagram of an HTP processor. The processor consists of three main parts: an input electronic unit for image acquisition, a TV camera, a CCD sensor, etc., and its preprocessing of the fiber optic signal processor 2 and the HTP rotary processor. By image preprocessing is meant the extraction of input discrete signals x, y. and in (x., y.) the optical fiber processor 2 of the image. The optical fiber signal processor 2 comprises an optical circuit 10 of single-mode fibers 10, an electronic processor 5 for adjusting the parameters of the circuit, interconnecting single-mode optical fibers 6 for interconnecting the optical circuit of single-mode fibers 6 with input electro-optic ^θ output opto-electronic 10 , 11 converters of input, resp. output electrical signals. Optical signals are marked with an asterisk in the attached figures. As input electro-optical (E / 0) converters we use semiconductor injection lasers, as output opto-electronic (0 / E) converters 10,11 use photodiodes PIN, resp. avalanche photodiodes (APD). Circuit diagram of single-mode fiber optic circuit? 2 is shown in FIG. Its function is in the optical field to perform the calculation ^^ in terms of (4) and memorize the weights of the voices in (x ^ y ^) the revival process or ^ * HTP ^ 3j.

fiber single-scorch unit 12 coupled to an electro-optical 7 and an opto-electronic (10) for a single-mode optical fiber 13.14 lengths L _Q1 and 1θ ₂ · Calculation of values ^ ' _r (x _i , y ^)

In the optical region, it is performed in a systolic processor formed by the interconnection of T optical fiber arithmetic units 15 capable of performing the computation of the relationship (4). The pulse optical signals x ^ and y ^ are input to the optical fiber arithmetic units 15 from directional couplers 16 connected to the bus optical fibers 17 and 18. The bus fibers 17 and 18 are terminated by reflective elements 19 at the end against reflection. The fiber arithmetic units 15 are coupled to the output bus fiber 21 using directional couplers 20. The delay sections of the switch fibers 22 with lengths L 1, 1 = 1, 2, 3 and 1 = 1, 1, 2, 3 are selected such that the discrete output signals ý r ^ ^ ^x i 1 ^ synchron are synchronized in working processor mode. The wiring diagram of the optical fiber arithmetic unit 15 is shown in FIG. It is essentially a discreetly working analog fiber optic signal processor for performing stage computations of relation (4). Optical pulse signals x ^ y ^ input to the processor via optical fibers 23.24 and output signals Q _r (X1, yj) output via optical fiber 25. The arithmetic unit 15 consists essentially of two full-fiber Mach-Zehnder interferometers 26.27 formed by the connection two 3 dB optical fiber directional couplers 28.29, respectively. 30.31. ^a piezoelectric phase modulator 32, respectively, is connected ⁱⁿ one arm of the optical fiber Mach-Zehnder interferometer thus formed. Then, the optical fiber Mach-Zehnder interferometers 26.27 realize the products in (4). The signals exiting the splitters 29,31 P ° of fibers 34,35 are summed in the fiber optic splitter 36. The directional splitters 28,529,30,31 and the optic splitter are implemented by optical fiber welding technology.

The parameters of the circuit are used to set the operating constants ^k lr ^{θ k} 2r ' ^{Γ =} multipliers realized by whole-fiber Mach-Zehnder interferometers 26.27 in cooperation with piezoelectric phase modulators 32.33. in the individual stages of the optical fiber of arithmetic units 1 5. Furthermore, the processor 5 controls the operation of the optical fiber recirculation memory * ^ 9 and synchronizes the operation of the signal processor of the optical fiber 2 with an inlet ^and an electronic unit ^ ^{O, and} D votovacím processor '* Tffp ^ 3 _^> Votovací is an electronic processor for realizing the voting process in calculating the spectral coefficients HTP S (gf) in terms of (6).

The present invention relates to the field of electronics (optoelectronics, fiber optics). It solves the problem of technical implementation of specialized problem-oriented fast HTP processor.

It is an object of the present invention that in the process of calculating HTP spectral coefficients on a specialized transform processor, an optical fiber signal processor 2 (FIG. 1) is used, connected by its inputs to the electronic input unit 1 and its outputs to the HTP 2 electronic processing process. The fiber signal processor 2 is realized by an optical circuit of single mode fibers fed by optical signals from electro-optical converters 2.8. ^and Z, controlled by the processor, before setting the parameters of circuit 2 ^and its outputs connected to opto-electric converters 10, 11. 0P ~ Single Circuit Fiber Optic Fiber / VFig. 2), consists of a special fiber y y tic recirculation memory M2 and.

IN

- from the arithmetic part, which is formed to the bus fibers 1, 7, 8, and 21 by means of directional taps 16, 20 connected to the optical fiber arithmetic units 15. The optical fiber arithmetic unit 15 is composed of two whole ₍ fiber Mach-Zehnder interferometers). 26.27 formed from two 3 dB optical fiber couplers 28.29 and 30.31, respectively, with a piezoelectric phase modulator 32 and 33, respectively, being connected in one of the intermeters arms. The outputs of the Mach-Zehnder interferometers' 34.35 are connected to optical signal combiner 36.

The device according to the invention is useful in systems where the spectral coefficients of the HTP image need to be calculated very quickly (in real time). The speed of operation of the whole HTP processor (FIG. 1) is essentially limited by the connected electronic input unit 6 and the HTP2 electronic spin processor. Applications of such systems are related to HTP features in the areas of pattern recognition and scene analysis. These can be used in military engineers (Target tracking and detection, radar image analysis, etc.), navigation purposes, Xautonomous robots, and sub-processing of biomedical images, scene analysis in industry and robotics, product cycles, etc.

Claims (3)

4 'Hough line optical fiber processor, characterized in that it is composed of an optical fiber signal processor (2) connected by its inputs to the electronic input unit (1) and the outputs to the electronic processing processor of the Hough Line Transformation (3), wherein the optical fiber signal processor / ge is formed by an optical circuit IfT of single mode fibers fed by electro-optical converters (7, 8, 9), controlled by the processor for adjusting the parameters. (S) and outputs connected to opto-electric converters (10, 11) <. · The optical fiber processor of the Hougfro line transformation according to item 1, characterized in that the optical circuit (4) is of single mode optical fibers and consists of an optical fiber recirculation memory (12) and a set of T optical fiber arithmetic units (15) connected by its through the fiber optic directional couplers (16) to the bus fibers (17, 18) and through its output via the directional couplers (20) to the fiber optic directional couplers (16); an output collector fiber (21) i 3 · The Hough Transform® optical fiber processor of the line of claim 2, wherein the optical fiber arithmetic unit (1g) consists of a pair of full-fiber Mach-Zehnder interferometers (32, .33) consisting of two 3 d8 optical fiber taps (28). 29), respectively. (30, 31), wherein in one of the arms of these interferometrovýje connected piezoelectric íázový modulator (32, resp. 33) 7Tinterferometre ^with ifsTisvojimi inputs connected to the fibers (23, 24) and exit to the fibers ^ (14 _to 35 ^, which are established with to an optical full-fiber optical signal (36) connected to the output fiber (25).