JPS61221982A - Calculating device for surrounding length of picture pattern - Google Patents

Abstract

PURPOSE:To obtain accurately the surrounding length of a desired area in a picture pattern by delivering the number of sides where a noticed picture element touches background picture elements. CONSTITUTION:A side number deciding circuit 7 decides the number of sides to each picture element of a picture pattern shown by either one of discrimination codes 0-4 for each picture element ('0' shown by a blank part). A counting circuit 8 uses the discrimination codes given from a delay circuit 5' as addresses to read out the storage contents from a random access memory 8b. An adder 8a adds the value of the storage contents with the output of the circuit 7, and this added value is written on the original address of the memory 8b. Then the outputs of the circuit 7 are integrated for each discrimination code and stored in the memory 8b. These processed can be performed by a pipeline and the surrounding length of a picture pattern can be obtained in a short time.

Description

[Detailed Description of the Invention] [Summary] An image pattern perimeter calculation device that accurately and quickly calculates the perimeter of an area composed of pixels of the same type in an image pattern composed of rectangular pixels. It is configured so that it can be calculated.

[Industrial application field]

The present invention relates to a device for calculating the perimeter of a region identified by type in an image pattern, and more specifically, to a device configured to accurately calculate the perimeter.

In the recognition of images including characters, figures, etc.

Typically, features extracted from the image pattern to be recognized.

The type of image pattern to be recognized is determined by comparing it with features of the same type extracted in advance from various known image patterns.2 The type of image pattern to be recognized is determined based on the degree of similarity between the two. The area, perimeter, etc. of the image pattern are used.

At this time, it is desired to provide an apparatus that can accurately and quickly calculate the perimeter of one image pattern.

[Conventional technology]

FIG. 5 is a block diagram showing the principle of a conventional example of an image pattern perimeter calculation circuit.

Reference numeral 1 denotes an image memory that stores an image pattern identified as one of a plurality of types including the background for each pixel, using each identification code for each pixel.

Reference numeral 2 denotes a readout circuit that reads out the identification code stored in the 9-image memory 1 pixel by pixel by rask scanning.

Reference numeral 3 denotes a binarization circuit that binarizes the identification code read out by the readout circuit 2 according to the type of each pixel, for example, by setting a background pixel to "0" and setting other pixels to "1".

Reference numeral 4 denotes an edge pixel detection circuit that detects pixels constituting the edge of a region formed by consecutive pixels determined to have one value, for example, "1" by the binarization circuit 3.

5 is a delay circuit that provides a certain delay to the identification code read by the reading circuit 2;

6 is a counting module that counts the number of pixels detected by the edge pixel detection circuit 4 for each identification code.

An edge pixel detection circuit 4 detects an edge pixel by examining 8 neighboring pixels of the pixel of interest using a 9, for example, 3×3 filter, and a counting circuit 6 detects each pixel given through a delay circuit 5. The number of detections by the edge pixel detection circuit 4 is counted for each identification code.

[Problem that the invention seeks to solve]

The image pattern perimeter calculation device having the above configuration calculates the perimeter of a desired area in one image pattern based on the number of pixels forming the edge of the area, and has a problem of poor accuracy.

Therefore, it is an object of the present invention to accurately determine the perimeter of a desired area in an image pattern.

[Means for solving problems]

FIG. 1 is a block diagram of the principle of the present invention, except for the same reference numerals as in FIG. 5.

Reference numeral 7 denotes a side number determining circuit which determines, for each pixel, the number of sides where a pixel determined to have one value, for example, "1", contacts a pixel determined to have another value, for example, "0" by the binarization circuit 3.

A counting circuit 8 counts the number of sides determined by the nine-side number determining circuit 7 for each identification code.

5' is a delay circuit that provides a delay corresponding to the delay in the binarization circuit 3, the side number determining circuit 7, etc. to the identification code read by the reading circuit 2.

[Effect]

That is, the identification code of each pixel stored in the image memory 1 is read out one pixel at a time by rask scanning, and
For example, by the value conversion circuit 3.

The background pixel is set to "0" and the other pixels, that is, the image constituent pixels are set to "1#" and binarized.

Next, the side number setting circuit 7 checks the values of the pixel of interest fO and its four neighboring pixels f1 to f4 using a filter having the configuration shown in FIG.

According to the relationship shown in FIG. 2), the number of sides where the pixel of interest fO contacts the background pixel is output.

Further, the output of the variable determining circuit 7 is counted by a counting circuit 8 for each pixel identification code given via the delay circuit 5'.

As a result, excluding 9 pixels in one image pattern, for example, background pixels,
The perimeter of a region formed by consecutive pixels identified as the same type is calculated.

〔Example〕

FIG. 3 is a block diagram of one embodiment of the present invention.

The side number determination circuit 7 includes shift registers 7a and 7b each having a bit length corresponding to one scanning line of one image memory l, registers 7c to 71 each having one bit length, and a read-only memory (1) that stores the table shown in FIG. 2(b). ROM) by 7j.

Further, the counting circuit 8 includes an adder 8a and a random access memory (RAM) 8b, respectively.

Note that the binarization circuit 3 can be configured by storing a conversion table or by a one-domain memory, and the delay circuit 5' can be configured by a shift register.

With such a configuration, the side number determination circuit 7 first determines an image pattern represented by an identification code of 0 to 4 for each pixel (however, blank areas are replaced with 0), as illustrated in FIG. 4(a). ) for each pixel.

The number of sides as shown in FIG. 4('b) is determined (blank areas represent 0).

The counting circuit 8 also uses the identification code given from the delay circuit 5' as an address in the random access memory 8b.
The stored content of is read out, and the value and the output of the side number determination circuit 7 are added by the adder 8a, and written to the original address of the random access memory 8b, and the output of the side number determination circuit 7 is the identification code. It is accumulated every time and stored in the random access memory 8b.

In the above embodiment, all processing can be performed by pipeline processing, and one perimeter can be obtained in a short time.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to accurately determine the perimeter of a desired area in an image pattern.2 For example, when this is used in a pattern recognition device, the recognition accuracy can be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle of the present invention. FIGS. 2(a) and 2(b) are diagrams explaining the principle of the present invention. FIG. 3 is a configuration diagram of the embodiment. FIGS. 4(a) and 4(b) are explanatory diagrams of the same embodiment. FIG. 5 is a block diagram of a conventional example. In the figure. 3 is a binarization circuit, and 5' is a delay circuit. 7 is a side number determining circuit, and 8 is a counting circuit. 7a and 7b are shift registers, and 7c to 71 are registers. 7j is read-only memory + 8a is adder. (of (ip) Actual example of Segeki Kokuryo 4 Mouth-filled white potion example 0 Fukuchi・no 2 C Rihata 52

Claims (1)

[Scope of Claims] By consecutive pixels identified as the same type in an image pattern composed of rectangular pixels and identified for each pixel as one of a plurality of types including the background. An image pattern perimeter calculation device that calculates the perimeter of a configured area, comprising: a binarization circuit (3) that binarizes the image pattern for each pixel according to the type; and the binarization circuit. A side number determining circuit (7) that determines, for each pixel, the number of sides where a pixel determined to have one value contacts a pixel determined to be the other value according to (3);
7) A counting circuit (8) for counting the number of sides determined in step 7 for each of the identified types.