SU1262539A1 - Device for selecting features when reading images - Google Patents

Abstract

This invention relates to automation and computing. The proposed device allows the selection, coding, and grouping of visual signs of the halftone image of objects and input of the received information into the computer. The local address field image generation unit breaks the field of view (or any raster area) into local fields containing the visual signs under study, and forms the addresses of the specified fields at the output of the programmable depgaphrarator, received by the distribution unit of the visual signs groups by parameter - the luminance gradient direction code, coming from the output of the coding unit of the image elements by the direction of the luminance gradients to the second move the address register, wherein the CO formed C. address of the array. indicative information generated in the memory block during one half-frame of the standard television scan and read after processing all local fields into the on-line memory of the computer. The device is designed to perform image pre-processing in the technical system of the robot's vision. 2 hp f-ly. 1 il.

Description

The invention relates to automation and computer technology and can be used to allocate, encode, group visual signs of a grayscale image of objects and enter the received information into a computer. The device is oriented for use in adaptive robotic vision systems.

The purpose of the invention is to increase the accuracy and speed of the device.

The drawing shows the block diagram of the device.

The device contains a reading unit 1, an analog-to-digital converter 2 delay elements 3 - O, adders 1.1-14, blocks 15 and 16 subtraction, blocks 7 and 18 of the module adder adder 19., comparator unit 20, encoding unit 21, scanner unit 22, the unit 23 for generating the address of the local image field, which consists of the first element AND-NOT 24, the frequency divider 25, the second element AND-NO 26, the first counter 27, the clock pulse generator 28, the second counter 29 and the programmable decoder 30. The device includes also block 31 distribution of signs, to The latter consists of address register 32, memory block 33, counter 34 and control unit 35.

For communication with a computer is a block 36 of receiving and transmitting information.

The device works as follows.

When ready to work, the computer generates on the registers of the unit 36 for receiving and transmitting information the boundaries of local fields, the threshold value of the luminance gradient and the start signal of the device. Upon receipt of a start signal, which is fed to the second input of the AND-HE element 24j, the device waits for the occurrence of a frame sync pulse at the first output of the scanner unit 22. When a frame sync pulse appears at the second input of the AND-24 element, the signal from the output of the specified element enters the frequency divider 25, which divides the frequency into two, which corresponds to the sample for processing one half-frame of the television raster. The NE-NE element 26 is triggered when the line sync pulse appears on the selected half-frame, which comes from the second output of the sync block 22 sweep to the first input of the element

AND-NOT 26, and the signal from the output of the splitter 25 frequency, which is fed to the second input of the element AND-NOT 26. The signal from the output of the element AND-NOT 26 starts the generator 28 clock pulses, and also enters the input of the counter 29, which forms the number (the troops (coordinate of the current image element along the OX axis). The output signal of the 28 clock pulse generator is fed to the input of the counter 27, which forms the element number in the row (coordinate of the current image pixel along the OS axis). 27 and 29, respectively, to the first and second inputs of the programmable decoder 30, which determines the identity of the image element to one of the local fields and generates the address of that local field.

The device operates with nine local fields into which the entire raster is divided (256 x 256 elements) or any area on the raster. The splitting is performed by a rectangular lattice. The boundaries of the local fields are blunt from the second output of the information receiving and transmitting unit 36 to the third input of the programmable decoder 30, The local field address is fed from the output of the programmable decoder to the first input of the address register 32.

Analog-to-digital converter 2 is started by clock pulses of generator 28, which are fed to a control input of an analog-to-digital converter (ADC) 2. The signal from the output of the ADC 2 is sent to the spatial differentiation circuit of the luminance function, performed on the basis of eight delay elements 3-10, four adders 11-14 and two blocks 15 and 16 subtractions. At the output of the first and second subtraction blocks 15 and 16, the derivatives of the luminance function are formed with respect to the X and Y coordinates. These derivatives are calculated at the tempo of the standard image sweep when scanning a raster with a 3x3-element local window. The obtained values of the derivatives of the luminance function are fed to the inputs of the first and second blocks 17 and 18 of the module calculation, respectively. The adder 19 calculates the magnitude of the gradient of luminance as the sum of the absolute values of the derivatives of the luminance function, arriving at its inputs from the outputs of blocks 17 and 18 of the calculation of the module. The magnitude of the luminance gradient module is fed from the output of block 19 to the first input of comparison unit 20, which is compared with the threshold value received at the second input of comparison unit 20 from the third output of information receiving and transmitting unit 36. If the form 1 value of the luminance gradient modulus equals or exceeds the threshold, then the output signal from the comparison unit 20 is fed to the control input of the coding unit 21, which encodes the selected image element with the luminance gradient direction code, otherwise the code is masked. The coding unit 21 forms the coding direction of the luminance gradient based on the values of the components of the gradient — derivatives of the luminance function with respect to the X and Y coordinates, coming from the outputs of the subtracting units 15 and 16 to the information inputs of the coding unit 21. The direction code from the output of the coding unit enters the second input of the address register 32. The characteristic distribution unit 31 builds a histogram of the distribution of coded elements along the directions of luminance gradients in local fields. The main operation of this block is to add an element with the corresponding gradient direction code to the group of previously detected elements from this local field. The operation is carried out in the event that at the output of the comparator unit 20 a signal is received, which arrives at the second input of the control unit 35. In this case, the control unit 35 generates control signals phasing in time the operation elements, i.e. reading data at the address contained in address register 32, from memory block 33 to counter 34, sending a signal to counter input of counter 34, reading the obtained value from the latter to the memory block at the same address. The address in register 32 is formed by combining in a single word the local field address (high bits) coming from the output of programmable decoder 30 to the first input of address register 32, vi of the luminance gradient direction code (low bits) coming from you 394 block stroke 21 coding to the second input of the address register 32. After processing all the image raster elements during one half-frame, histograms of the contour image elements distribution along the gradients p are formed in the device memory block spine for each of the nine local fields. The control unit 35 generates at its third output a readiness signal to match a computer to the array of indicative information. Further analysis of the image structure is carried out in a computer based on the generated histograms in local fields. The modes of these histograms correspond to the m – collinear differences in brightness with the same gradient direction, and the phase relations between the modes can correspond to vertices determined by the angle between the selected differences in brightness in a given local field. The absolute position of the modes is invariant to the image transfers in the field of view, and the phase relations are preserved when the image is rotated. At the addresses of local fields, information is retrieved about the spatial relationships between the selected visual features. The operation of the device with the computing machine is of a phase character, the computer forms the boundaries of local fields, the threshold value of the luminance gradient module and transmits the specified parameters to the device. During one half-frame, the device performs pre-processing of a halftone image and forms in the memory block an array of indicative information prepared for input into a computer. The computer enters the specified data array, transferring the device to the standby state of the new parameter values at which subsequent image processing is performed. After analyzing the obtained array of indicative information, the computer calculates new parameter values and transmits them to the device, waiting for the next data, etc. The initial oluton image on the raster 56 X 256 elements at 16 gradations of brightness contains approximately 32 KB of information. As a result of preliminary data processing output

The device contains no more than 288 bytes (in each of the nine local fields, no more than 32 directions of luminance gradients are coded, and the number of elements with a specific direction code does not exceed 256).

Claims (3)

Invention Formula 1, A device for extracting features when reading images, comprising a series-connected reading unit, an analog-to-digital converter, first and second delay elements, successively connected third and fourth delay elements, sequentially connected fifth and sixth delay elements, sequentially connected seventh and eighth elements delays, five adders, two subtraction units, the first inputs of which are connected respectively to the outputs of the first and fourth adders, the second inputs to the output the third and second adders, and the outputs to the inputs of the first and second modules of the module calculation, the outputs of which are connected to the inputs of the fifth adder, the output of which is connected to the first input of the comparison unit, the coding unit whose inputs are connected to the outputs of the subtraction blocks, the control input of which is connected to the output of the comparing unit, the scanning unit, the outputs of which are connected to the inputs of the reading unit, the receiving and transmitting unit, the first output of which is connected to the second input of the comparing unit, and the analog-to-digital output converter is connected to the input of the third delay element, with the first input of the first adder and the third input of the fourth adder, the output of the first delay element is connected to the input of the fifth delay element and the second input of the fourth adder, the first input of which is connected to the output of the second delay element and the third input of the third an adder, the second input of which is connected to the output of the seventh delay element, the output of the eighth delay element connected to the first input of the third adder and the third input of the second adder The second input of which is connected to the output of the sixth delay element, and the first input - to the output of the fourth delay element and the network input of the first sumator, the second input of which is connected to the output of the third delay element, which, in order to improve the accuracy and speed of the device , it contains the attribute distribution unit and the local image field address generation unit, the first, second, third and fourth inputs of which are connected respectively to the first and second outputs of the scanner, the second and third the outputs of the information receiving and transmitting unit; the first output of the local address image generation unit is connected to the control input of the analog-digital converter; the first, second, third and fourth inputs of the attribute distribution unit are connected respectively to the first and second outputs of the local image address generation unit and the outputs of the coding and comparison units, and the outputs of the attribute distribution unit are connected to the inputs of the information receiving and transmitting unit. 2. Device POP.1, characterized in that the block for forming the address of the local field of the image contains the first counter and the first AND-NOT element sequentially included, the frequency divider, the second AND-NOT element, the clock generator, the second counter and the programmable decoder, the output of which is the second output of the block, the output of the second element is NOT connected to the input of the first counter, the output of which is connected to one of the inputs of the programmable decoder, which controls the input of which is the fourth input of the block, the first input which is one of the inputs of the first NAND element, the other input of which is the third input of the block, the second input of which is the corresponding input of the second NAND element. 3. The device according to claim 1, characterized in that the attribute distribution unit comprises an address register, a memory unit, a counter and a control node whose inputs are the first and fourth inputs of the block, the second and third inputs of which are the inputs of the address register, output which is connected to the first input of the memory unit, the second input of which is connected to the first output control unit, the second output of which is connected to the first input of the counter, the second input and the output of which are connected respectively to the output and 1262539 the third input of the memory unit, the output of which and the third output of the controller node are connected to the inputs of the information receiving and transmitting unit.