JPS60168277A - Controller of picture memory - Google Patents

Abstract

PURPOSE:To accelerate address calculation and to simplify circuit constitution by writing rotational coordinates necessary for boundary tracking in a ROM, by renewing an address of the ROM and modifying contents of a boundary register at a high speed. CONSTITUTION:X-Y coordinates of the boundary picture element concerned are stored in a center point register 30 of a picture memory controller, those of adjacent picture elements are stored in a ROM34. An address of the ROM34 is specified by a rotational address register 32, and the outputs of the ROM34 and the register 30 are added by an adder 36. An output of the adder 36 is held in a picture memory address register (boundary register) 38, reading or writing of contents of a picture memory 14 is executed. By specifying an address by the register 32, the address of the ROM34 is renewed, the address of adjacent point of the boundary picture element concerned is calculated. Thus the address calculation can be accelerated and the constitution of a controller can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an image memory control device, and more particularly to an image memory control device that uses a computer to automatically track image boundary lines.

Conventionally, regarding this type of image processing, for example, Sanpo Publishing,
Angoin, Nakajima, “Computer Image Processing” PP, 66-
The method shown in No. 67 is generally adopted. That is, as shown in FIG. 1, the A/D converter 12 converts the video signal output from the camera 10 into a binary 4k17 signal using an analog/digital converter, and writes this binary output into the image memory 14. Furthermore, the information stored in the image memory 14 is converted into an analog signal by a D/A converter 16,
It was configured so that it could be output to the monitor 18 and read and written by the control device 20.

In the image processing apparatus configured as described above, for example, the second
Let us consider a method of automatically tracking the boundary line of a binary image shown in the figure, for example, in a clockwise direction. As shown in Figure 2
It is assumed that an XC-register and a YO-register (not shown) are provided to indicate the current positions of the Y-axis and the Y-axis, respectively.

Now let the coordinates of a Pt -s be (X (i-t),
Y(1-+)), the direction of the point p1-1 with respect to the point P1 is determined by equation (1).

If the current state is as shown in FIG. 2, then x=-1. It is understood that Y=Q, and that the point P1-3 exists on the left side of the point P1.

At this time, in order to track the boundary pixels, it is sufficient to check whether each adjacent pixel is a black area or a white area in a clockwise direction, that is, in the order shown in FIG.

Specifically, first, calculate the difference and sum of work X and work Y as shown in equation (2).

In this case, the value is 0.1. Or, if it is -1, it will remain as 0.1. By replacing it with -1 and, if the value is -2 or 2, replacing it with -1°1, respectively, the direction of the next search point can be determined in a non-order manner.

The above operations can be summarized as shown in the following equation (3).

Here, SGN is a code extraction function and represents the code in parentheses,
When 0≧0, 1.0=0, and 0.0<O, it indicates -1, respectively.

In addition, when the direction is counterclockwise, the sum is improved in equation (3),
Just substitute the difference into 6.

Therefore, A pl-t (xc, Yo) is centered KL
, to sequentially scan neighboring points around it clockwise.

The coordinate rotation calculation shown by the above equation (4) is performed at point ■,
■, ■, ■ and I [must be executed next.

However, in order to execute the coordinate rotation calculation of equation (4) above, the addition/subtraction and sign determination processing shown in equations (1), (3), and (4) above must be performed on the computer each time. This method had the disadvantage that it had to be executed in software and required a large amount of boundary tracking time.

(Object of the Invention) The present invention has been made in view of the above points, and aims to speed up address calculation by simplifying the address rotation update operation, thereby making it possible to speed up boundary tracking processing. An object of the present invention is to provide an image memory control device that can draw curves of arbitrary shapes at high speed.

(Summary of the Invention) In order to achieve these objects, the present invention combines the output of a center point register that stores the X-X coordinates of the currently focused boundary pixel and the rotation of adjacent pixels addressed by a rotation ROM address register. An adder adds the outputs of the ROMs that store the coordinates. The output of this adder is held in an image memory address register (boundary coordinate register) to read the contents of the image memory. As a result, the address of the image memory is updated by changing the address of the rotating coordinate storage ROM, and the address of the adjacent point of the boundary pixel of interest is calculated.

(Embodiment) Hereinafter, one embodiment of the present invention will be described with reference to the attached nine drawings.

FIG. 3 is a vine diagram showing an embodiment of the image memory control device according to the present invention. In the figure, 14 is the image memory mentioned above. Reference numeral 30 denotes a center point register which independently stores the X-Y coordinates of the boundary pixel of current interest. 32 is a rotation ROM address register, which will be described later.
Specify the address of OM. The lyrics are the third part mentioned above in the ROM.
The rotational coordinates of the adjacent pixels shown in the figure are stored. 36 is an adder, and in the embodiment, two circuits in total are required, one circuit each for the X adder and the Y adder. A is a boundary coordinate register that functions as an image memory address register, and it is added!
! 7 and 40 are increment circuits which hold the output of 136 and access (l!! write) the contents of the image memory 140, and in the embodiment, increment the contents of the rotary ROM address register 32 by l@ next 1.

One embodiment of the present invention has the circuit configuration as described above, and its operation will be explained next.

First, in step 1, enter the center coordinates (XO
, YO). Also, in step 2, the initial rotation scanning direction (for example, 0) is set in the rotation ROM address register 32.
Set. In step 3, the adder 36 registers (
) and the output of ROM34, and the output of boundary register 3 is added.
Hold at 8. In step 4, the contents of the image memory 14 designated by the boundary coordinate register are read out. Further, in step 5, if the read data from the image memory 14 is not a boundary pixel (for example, a black pixel).

ROM address register 3 by increment circuit
The contents of 2 are updated by +1, and the processing of steps 3.4.5 is repeated. Further, in step 6, if the read data of the image memo +714 is a boundary pixel, the contents of the boundary coordinate register 38 are registered in the boundary list, and the center point register 30
Also write to the 3-bit rotating ROM address register 3.
2 is converted into ROM ADRMIW using the well-known address conversion formula shown by the following formula, which corresponds to the rotational coordinate calculation in FIG.
= (ROM ADRo:c, D+6) MODB and repeat step 3.4.5.

Here, MOD means the remainder of integer division. In this way, in this embodiment, 8GN (ZX-Z
Y), FiGN (ZX+ZY) (D calculation is no longer necessary.

Since the address rotation update operation for accessing the image memory can be done by changing the ROM address, address calculation can be speeded up. Therefore, the boundary tracking process is faster than in the past, and chain-coded arbitrary shape curves, which conventionally required a lot of time for image processing, can be drawn at high speed.

In the above embodiment, the case of rotational scanning in the clockwise direction has been described, but in the case of rotational scanning in the counterclockwise direction, the values of ΔX and ΔY of the outputs in FIG. 3 may be exchanged.

Further, in the case of boundary tracing in a %8-connected relationship, the increment circuit 40 may be a circuit that adds 1 to the normal register contents, but in the case of boundary tracing in a 4-connected relationship, a circuit that increases the register contents by 2 may be used.

(Effects of the Invention) As described above, the present invention allows rotational coordinates necessary for boundary tracking to be written in advance in the ROM, and by updating this ROM address, the contents of the boundary coordinate register can be changed at high speed. I have to.

Therefore, since the address calculation speed is increased, boundary tracing processing can be realized at a higher speed than in the past with a simpler circuit configuration.

Further, by applying the present invention, excellent effects such as being able to draw arbitrarily shaped curves converted into chain codes at high speed can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional image processing device.
FIG. 2 is a detailed explanatory diagram illustrating a method for tracing the boundary line of a binary image using the apparatus shown in FIG. FIG. 2 is a block diagram showing an example of an image memory control device according to the present invention. 10...TV camera, 12...A/D converter, 1
4... Image memory, 20... Control device, 30...
Center point register, 32... Rotation ROM address register, 34... ROM. 36... Adder, 38... Image memory address register (-boundary register). Figure 1 x

Claims (1)

[Claims] (1) The output of the television camera is converted from analog to digital and written to the image memory, and the digital image processing unit is used to store the X-X coordinates of the boundary pixel of interest. a center point register, a ROM that stores rotational coordinates of adjacent pixels, a rotational ROM address register that specifies the address of this ROM, and the R
an adder that adds the output of the OM and the output of the center point register; and an image memory Vresle that holds the φ value of this adder and reads and writes 8 volumes of the image memory. By changing the address of the ROM, the address of the image memory is updated and the address of the adjacent point of the boundary pixel of interest is calculated. Image memory control device featuring features.