JPH04360287A - Binary image processor - Google Patents

Abstract

PURPOSE:To rapidly lead out the maximun and minimum values of a target in both the X and Y directions without using an image memory by providing this binary image processor with line buffers for two systems, an area information table, a means for detecting the start and end of an area and so on. CONSTITUTION:This binary image processor is provided with the line buffers 5, 6 for two systems which alternately execute writing and reading in each line. The maximum and minimum values of each closed area in the X and Y directions of the area and connecting information between respective areas are stored in an area information table 9. The processor is also provided with the area start/end detecting parts 7, 8, a buffer control part 3, an area information table control part 10 and so on. The connecting information of the table 9 is formed based upon the input image information and the information of the preceding line read out from the buffers 5, 6. Consequently, the maximun and minimum values of the target in both the X and Y directions can rapidly be led out.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus for processing binary images, and more particularly to an apparatus for determining the size of an area.

0002

[Background Art] In image recognition of binary images, the size of an object, that is, the maximum and minimum values in the X direction, and the maximum and minimum values in the Y direction, are useful as feature quantities that express the object. becomes. The present invention relates to a device for deriving the maximum value and minimum value in the X direction and the maximum value and minimum value in the Y direction of this object.

Conventionally, the derivation of these numerical values is as follows:
The image information was once written into the image memory, and then the boundary tracing method or fill-in method was used.

However, these methods require an image memory, and it is difficult to increase the processing speed.

[0005]

[Problems to be Solved by the Invention] The present invention solves the problem of
The purpose of this method is to quickly derive the minimum value and maximum value in the direction and Y direction, respectively, without using an image memory.

[0006]

[Means for Solving the Problems] The present invention provides two lines of line buffers that hold input image information and addresses of area information tables, and a maximum value and a minimum value in the X direction and Y direction of each closed area. and an area information table that holds connection information between areas, means for detecting the start and end of an area, a control means for controlling the address, reading, and writing of the line buffer, and an address, reading, and writing of the area information table. and control means for controlling.

[0007]

[Operation] Since the present invention has the above-described configuration, it is possible to finish scanning the target image without using image memory by using the previous line information, area start and end information, and information in the area information table. At the same time, the minimum and maximum values in the X and Y directions of a plurality of closed regions included in the target image can be created in the closed region information table.

[0008]

Embodiment FIG. 1 shows a block diagram of an embodiment of the present invention. Further, FIGS. 2 and 3 show the configuration of the line buffer and the configuration of the area information table. FIGS. 4, 5, and 6 show processing flows for explaining the operation of the configuration shown in FIG.

Embodiments of the present invention will be described below with reference to these figures.

As shown in FIG. 1, image data from an image reading device 1 such as a camera or a scanner is binarized by a binarization circuit 2. The binarized image data is alternately written into the first line buffer 5 and the second line buffer 6 via the selector 4 under the control of the line buffer control unit 3. The data is sent to area start/end detection units 7 and 8. At this time, the line buffer to which data has not been written is read in order to refer to the information of the previous line.

The configuration of this line buffer is shown in FIG. Here, the white/black information bit indicates whether the binarized data is a white pixel or a black pixel, and if the white/black information is a black pixel, the area information table area NO part is an area information table that includes the black pixel. It holds the area NO. However, this area N
O has meaning only where a black pixel starts, that is, where a black area begins. In FIG. 2, N indicates the number of pixels in the X direction.

In FIG. 1, area information table 9 is a table that ultimately holds information on the size of each area derived according to the configuration and operation of the present invention, and has the configuration shown in FIG. 3.

As shown in FIG. 3, the area information table includes, for each area number, the minimum value in the X direction [XMIN(NO)], the maximum value [XMAX(NO)], and the minimum value in the Y direction [YMIN(
NO)], maximum value [YMAX(NO)], and area connection information [LINK(NO)]. Here, the area connection information holds the number of another area to which the area is connected, and in the configuration of the present invention, in the case of an area with a complex shape, the area connection information holds the number of another area to which the area is connected. It is provided because it is not possible to derive the size of the area by itself. In other words, multiple areas connected by connected information are
It shows that they are connected. This area information table needs to be initialized before inputting an image.

The creation of the area information table is performed under the control of the area information table control section 10 shown in FIG. In addition, in FIG. 1, the line address counter 11
is a counter that counts line numbers in the Y direction, and holds the current line number (I). Similarly, the pixel address counter 12 is a counter that counts pixel numbers in the X direction, and holds the current pixel number (J). The area start position register 13 stores the pixel number (XS
This is a register that holds T). address register 14
, 15 are registers each holding the area number of the area information table 9 held in the line buffer being read, that is, the line buffer at the time when the data of the previous line started the black area. In other words, it holds which number in the area information table 9 the black area of the previous line corresponds to. The area information table address counter 16 is a register that holds the number (AC) of the area information table to be created when a new area that is completely unconnected to the previous area is generated. It is updated one by one. Finally, the write address register 17 is set to the address (WA
DR), and is a register that holds address register 1.
4, 15, or the value of area information table address counter 16 will be entered.

The configuration of the present invention has been described above, and flow charts of FIGS. 4, 5, and 6 show how these means are actually controlled.

In the same flowchart as described above, I indicates the line number of the current line, J indicates the pixel number of the current pixel, WADR indicates the value held in the write address register 17, and ADR indicates the address register 14, 15.
AC is the area information table address counter 1.
6, and XST indicates the value of the area start position register 13.

FIG. 4 is an overall flowchart showing the processing of one pixel, and this is repeated for one line, and the line buffer 5
, 6 alternately and repeat for all lines. By repeating this process for all lines, information on all areas included in the input image is written into the area information table 9.

FIG. 5 shows details of the black pixel processing in FIG. 4. In FIG. 4, the processing is largely different depending on when the start of a black area is detected and when the inside of the black area is detected.
The contents of (WADR) are being manipulated.

FIG. 6 shows details of the white pixel processing in FIG. 4. In white pixel processing, write address register 1 is written when the end of the black area is detected.
The area information is set in the area information table 9 at position 7 (WADR), and the contents of WADR are written to the area start position of the current line buffer.

The configuration of the present invention is most effective by performing hardware processing as shown in this embodiment.
Similar processing can be performed using hardware, and it is also possible to perform processing using software. In this case, an image memory is required, but by using this processing method, it is possible to speed up the processing.

[0021]

[Effects of the Invention] By using the configuration of the present invention, the maximum and minimum values in the X and Y directions of a closed region included in the input image information can be derived in real time from the input image information without the need for an image memory. can do.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is a configuration diagram of a line buffer.

FIG. 3 is a configuration diagram of an area information table.

FIG. 4 is a processing flowchart showing the overall processing flow.

FIG. 5 is a processing flowchart showing the details of processing of black pixels.

FIG. 6 is a processing flowchart showing the processing details of white pixels.

[Explanation of symbols]

3 Line buffer control section 5 First line buffer 6 Second line buffer 9 Area information table 7 First area start/end detection unit 8 Second area start/end detection unit 10 Area information table control unit

Claims (1)

[Claims] Claim 1: A device for deriving the maximum and minimum values in the X direction and the maximum and minimum values in the Y direction of a closed region of a binary image, which holds input image information and the address of a region information table, and calculates the maximum and minimum values for each line. Two lines of line buffers for which writing and reading are performed alternately, and an area that holds the maximum value and minimum value in the X direction, the maximum value and minimum value in the Y direction, and connection information between areas for each closed area. an information table, an area start/end detection unit that detects the start and end of each area within a line, a line buffer control unit that controls reading and writing of the line buffer, and an area that controls reading and writing of the area information table. The area information table includes an information table control unit that stores the maximum value and minimum value in the X direction, the maximum value, the minimum value in the Y direction, and An image processing device for binary images, characterized in that it creates connection information between regions.