SU1517047A1 - Device for etracting image features - Google Patents

Abstract

The invention relates to automation and computing and is intended for use in image processing systems. The aim of the invention is to expand the functionality of the device by highlighting the features of the higher and lower spatial frequencies of the images. The device comprises a scanning aperture shaping unit, four adder units, five multiplexers, two comparison units, and a comparison element. Independent selection of features of spatial frequencies of images is achieved by switching the device with an external control signal. 2 hp f-ly, 3 ill.

Description

The invention relates to the field of automation and computer technology and is intended for the use of E image processing systems for the tasks of technical vision, topography, processing of photographs.

The aim of the invention is to expand the functionality of the device by highlighting the signs of high and low spatial frequencies of the images.

Figure 1 shows the current aperture of the image being processed; 2 and 3 is a block diagram of the device.

The current aperture (electronic window) is formed from the elements of the image a, b, c, d, f (m, n), e, f, g, h, as shown in position 1 of Fig. 1. This aperture runs along the lines of the image,

The device contains a block 2 of forming a scanning aperture, made on two elements 3 and 4 of the video signal time delay by the duration oAHofi of the image line and from six elements 5-10 of the time delay by the duration of one discrete image point, two identical operational nodes II and 12, the element 13 comparisons and multiplexer 14.

Each of operational nodes 11 and 12 contains two blocks 15 and 16 adders, two multiplexers 17 and 18 and a comparison block 19, consisting of the actual comparison element 20 and an EXCLUSIVE OR 21 element. Each of the above adder blocks consists of one differential one and one - direct 23 adders connected by inputs to the corresponding outputs of the block of formation of scanning apertures.

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The blocks of the sum of the ora of the operational nodes I 1 and 12 are respectively the first, second, third, and fourth blocks of the device adders.

The multiplexers II and 12 nodes are respectively the first, second, third, and fourth multiplexers of the device.

Comparison units of nodes I1 and I2 are respectively the first, second units of the device comparison.

Multiplexer 14 is the device's fifth multiplexer.

As elements 3-10 of the time delay (Fig. 2), any shift registers can be used in the device, for example, IC chips 555 IR24, recruited to the appropriate amount of delay and clocked with the image sampling frequency. As adders 22 and 23 are AL on IC chips 555-1111, quality. the elements 20 and 13 of the comparison are the chips 555SP1 intended for this purpose, the multiplexers 14, 17 and 18 are the chips 555KP2, and the logic element 21 is the chip 555LE1.

The device works as follows.

In one of the operational modes, the nodes calculate the brightness gradients.

The magnitude of the gradients is calculated using differential adders 22, included in blocks 15 and 16 of the sum of the tori of operational nodes 11 and 12, in each separate direction simultaneously. The resulting differences of values are compared, then in pairs in each operational node with a helper, block 19, the output of which determines the comparison sign and control multiplexer 17, selects the maximum of the compared values by appropriately connecting the named multiplexer to the required block of adders and transmitting this value to output of a specific operational node. The pairwise allocated maximum differences are finally compared by element 13 and using multiplexers 14 controlled by this element, the largest of all gradient values is output to the device, determining the result of processing. During the entire procedure described sig

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The control of the device, maintained at a constant level and acting on the control inputs of the comparison block 1 and multiplexer 14, unambiguously determines the order in which the reallocated and the whole gradient gradient calculation mode are selected. After processing, the image contains only the high-frequency components of its spatial frequency spectrum, which are the outline features of the objects.

5 In another mode of operation of the device, more precisely, of its operational nodes, accompanied by a change in the control signal to the opposite logical value, in addition to separating elementary gradients in blocks 15 and 16 of adders occurring in the same way, the average value of luminance is calculated for each corresponding aperture direction with direct adder 23. Due to the use of a logical element EXCLUSIVE OR 21 in block 19 comparison, inverting the output signal of the latter, the multiplexer 17 pr it lowers the output of its operational node to the same one, and the smallest of the compared differences, Odovhremenio with this, the multiplexer 18 will transmit the average value of brightness in the direction for which the minimum difference is determined. Comparing the differences between the outputs of node 11 and 12, the element 13 connects the multi; Plexor 14 to the output of the mean value of the one in which the least gradient was determined. This will occur due to the presence of a corresponding external input signal at the input of this multiplexer. The result of selecting the recognition 1: image in this mode will be directly opposite to the previously described, i.e. High-frequency noise and noise will disappear from the image. However, it should be emphasized that sharp drops from the boundaries of extended objects will be preserved; the device will behave like a median filter.

Claims (2)

1. An apparatus for extracting image features comprising a block 0 five 0 five 0 5.15 forming a scanning aperture, the outputs of which are connected to the inputs of four blocks of adders, are required because, in order to expand the functionality of the device by highlighting the signs of high and low spatial frequencies of images, it additionally contains There are two multiplexer comparison units and a comparison element, the differential output of the first and fourth blocks of adders are associated with the first information inputs of the first and fourth multiplexers, respectively; the input inputs of which are connected respectively to the differential outputs of the second and third blocks of adders, the direct outputs of the first and fourth blocks of adders are connected respectively to the first information inputs of the second and third multiplexers, the second information inputs the outputs of the second and third blocks of adders, the first and second information inputs of the first comparison block are associated respectively with the first and second information inputs of the first multiplexer, the first and second th second data inputs of the comparator associated respectively with the first and second data inputs of the third multiplexer 7 the control inputs of the first, second, third and fourth multiplexers are connected respectively to the outputs of the first and second comparison blocks, the control inputs of which are combined and are the control inputs of the device, the output of the first multiplexer is connected to the first input of the comparison element and the second information: the fifth multiplexer, the output of the second multiplexer is connected to the first information input of the fifth multiplexer, the output of the third multiplexer connected to the second input of the comparison element and the third information input of the fifth multiplexer, the output of the fourth multiplexer is connected to the fourth information input of the fifth multiplexer, the first and second control inputs of which are connected respectively to the output of the comparison element and the control input of the device, and the output is the output of the device. 2. Device pop.1, which differs in that each comparison unit contains a comparison element, the inputs of which are the first and second information inputs of the comparison unit, and the output is connected to one of the inputs of the EXCLUSIVE OR element, the other input of which is is the control input of the comparison unit, and the output is the output of the unit. F.kg a i with V 15 iS. 13 eight /four