JPS6033679A - Moment calculating circuit - Google Patents

Abstract

PURPOSE:To obtain the moment of a closed loop area at high speed and simply by having a round along the edge of the closed loop area and using the tracing direction as a code of integration to integrate the moment cumulative value obtained from the coordinates of each tracing point. CONSTITUTION:An edge tracing part 4 traces the edge of a closed loop area within a pattern memory 2 to obtain the coordinates of each tracing point as well as to decide the direction of the tracing point and sends these obtained coordinates and the direction to an area totalizer 5 and a moment totalizer group 6 respectively. The totalizer 5 integrates an area from the input value. While the totalizer group 6 adds the moment cumulative value to each integrated value stored presently when the direction showing code is plus and subtracts the moment cumulative value from said integrated value when the direction showing code is minus respectively. When a tracing point comes back to its start point after having a round along the closed loop, a comparator 44 gives a coincidence signal to a control part 1. Detecting this signal, the part 1 informs an information processor that the obtained area and moment are applied for input of them.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recognition circuit for characters, figures, etc., and more particularly to a circuit for calculating the moment of a closed loop region in a bit pattern obtained by scanning a drawing or the like.

In image processing, characters and figures are often recognized. At this time, first or higher order moments are calculated in order to determine the center of gravity position and shape of characters or figures. For example, the first-order moment M11. M12 and the second-order moments M21°M22 and M2S are given by the following formulas.

In Equation (1), R is the graphic area in the closed loop, and (x, y
) are the coordinates of its internal bits. surface'! jtS is expressed as shown in formula (2)% (2) (2) From the determined values, the center of gravity position x, y, and variance V of the figure are calculated by formula (3).

Further, when the shape of the figure is an ellipse and the flatness is h, it can be written as follows, so the flatness can be known from these values.

Conventionally, in order to calculate the moment of a graphic area in such a closed loop, the bit pattern is rask-scanned, and the coordinate values and their square values or products of the pixels included in the closed loop are accumulated to calculate the cumulative total. Eyes had. However, conventional methods have the disadvantage that calculations are performed for each pixel, which takes time, and when the closed-loop region for which the moment is to be determined is complicated with other closed-loop regions, it takes time and effort to separate the regions. Ta.

An object of the present invention is to provide a moment calculation circuit that can quickly and easily calculate moments in a closed loop region.

According to the present invention, there is provided a pattern memory that stores a bit pattern, a write/read circuit that controls writing to and reading from the pattern memory, and a closed loop region in the bit pattern stored in the pattern memory. an edge trace section that traces the edge of the edge of the edge trace section, and one or more moment accumulations that calculate a moment accumulation value from the coordinates of the current position of the trace point given from the edge trace section and integrate it with a sign determined by the tracing direction. A moment calculation circuit is obtained, which is constituted by a circuit and a divider for controlling each of the circuits.

The present invention can also be further added to the surface.The moment 1 axis and area obtained by the present invention can be taken in by an external 'F1'!, child computer, etc., and the formula (3)
By performing simple calculations such as Equation 1 (4), it is possible to obtain the center of gravity position, shape parameters, etc. of the figure.

The moment calculation circuit of the present invention traces edges of a closed loop region from 1, uses the direction of the trace as a sign of *x/n, and calculates X at each trace point.

The moment cumulative value hA constant calculated from the y-coordinate is integrated. In other words, if the direction of the trace when projecting the trace point onto a predetermined straight line, for example, the The integrated value is subtracted from the integrated value, and the integrated value when the trace goes around once is used as the moment of the closed loop region.

Next, the principle of the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram of a closed loop area in a bit pattern for explaining the operation of the moment calculation circuit of the present invention. Although the closed loop region may have any shape, the shape shown in the figure will be described as an example. In the figure, point P is the rightmost point of region R, point P2 is the leftmost point of the convex region in region R, and point P3
is the rightmost point of the concave region, point P4 is the leftmost point of the region R,
Points PI, PJ, PK.

Let PL be a point on the edge having the same X coordinate value x■, and point PT be the topmost point of the area IL that is found first by rask scanning or the like. Moment calculation is performed as follows.

The explanation is to set the trace start point to the top point of area R (2).The trace direction is clockwise, and the correspondence between the trace direction and the sign of the integration is positive when it is in the positive direction of the X axis and negative when it is in the negative direction. . Since the section from point P4 to point P1 is traced in the positive direction of the X-axis, the moment cumulative value described later is added to the integrated value for this section, and the section from point P to point P is traced in the negative direction of the X-axis. Since the moment is traced, the cumulative moment value is subtracted from the cumulative value in this section, the section from point P2 to point P3 is traced in the positive direction, so it is added, and the section from point P3 to point P4 is traced in the negative direction, so the difference is Continue this operation until the trace goes around the area R.

The cumulative moment value differs depending on the order of the moment to be fitted, but for the five types of moments shown in 2 (1), the contribution of the line segment of length y drawn from each point (x, y) to the X axis is accumulated. Therefore, it becomes as shown in equation (5).

In this way, for example, when the X coordinate value is xl, the cumulative moment value ΔM of the point Pl is added to the cumulative value so far.
4j (xI, yI) (where i and J are formula (5)
The subscripts 1, 2 of ΔM in . ...) is added to the moment cumulative value ΔMIJ (XI, yL
), the point PK moment cumulative value ΔM1'' (xx
+ yx ) and subtract the cumulative moment value 4 (XI, ys )'F at point PJ, so in the end, the cumulative moment value between point P■ and point PJ and the cumulative moment value between point PK and point PL are The contribution to the moment of the minute area in xi within the area called value is added to the integrated value. Since this is done over the entire area, it can be seen that the integrated value of moments is the moment of the area. In addition, the area S is the same integration as above as a moment! +', can be obtained by performing the calculation on the y coordinate itself ζ instead of the product value ΔMij, and is disclosed in Japanese Patent Application Laid-open No. 58-
7512 Self-Product Calculation Circuit" is already known.

By incorporating the area calculation circuit into the present invention,
It is possible to construct a device that easily obtains the feature amount of a figure as shown in equation (3) (41).

FIG. 2 is a block diagram showing one embodiment of the present invention including an area calculation circuit, which includes a control section 1, a pattern memory 2, an R/W circuit 3, an edge trace section 4, and an area accumulation circuit. 5 and a moment accumulator group 6. The edge trace section 4 includes a start point register 41,
It is depicted by a current point register 42, a direction detection circuit 43, and a comparison circuit 44. The operation is as follows. An information processing device (not shown) such as an electronic TL calculator sends the bit pattern to the pattern memory 2 via the signal line 101 and stores it. The information processing device further sends the coordinate value of the trace start point PT to the start point register 41 and current point register 42 in the edge trace section 4 via the signal line 102 and the current point register 42, and stores them. The information processing device then sends a moment calculation command signal to the control unit 1 via the signal line 103. Control part 1
When receiving the moment l output command signal, it sends a clear signal to the area accumulator 5 and moment accumulator group 6 (three in Fig. 2) via the signal @104, and clears each accumulated value by 01. At the same time, a trace signal is sent to the R, /W circuit 3 via the signal line 105. When the R/W circuit 3 receives the trace signal, it transmits the coordinate value of the current trace point to the signal line 106.
received from the current point register 42 via
This is given as a memory address to the pattern memory 2 via the signal ffMIO7, and pattern data in the vicinity of the trace point, for example pattern data of 3×3 pixels centered on that point, is read out from the pattern memory 2 via the signal line 107. , which is applied to the direction detection circuit 43 in the edge trace section 4 via the signal line 108. Direction detection circuit 43
determines the trace direction from the pattern data, and indicates a plus sign when the trace direction is in the positive direction of the X axis, a minus sign when the trace direction is in the negative direction, and O when the trace direction is perpendicular to the X axis. is sent to the area accumulator 5 and the moment accumulator group 6 via the signal IJIIO. When the itu product accumulator 5 receives the X coordinate value of the trace point from the current point register 42 via the signal line 11-1 and the sign from the direction detection circuit 43 via the signal 1110, it integrates the X coordinate value by 1.
, the moment accumulator group 6 receives the x and y coordinate values of the trace point from the current point register 42 via the signal line 111, and the sign from the direction detection circuit 43 via the signal line 110, and calculates the moment accumulation. The values are calculated as shown in equation (5) and integrated.

That is, when the sign is positive, the y-coordinate value or the cumulative moment value is added to each currently stored integrated value, and when the sign is negative, it is subtracted from the integrated value. When the sign is O, the product Hp is not calculated. Then edge trace section 4
The current point register 42 in the current point register 42 receives the trace direction from the direction detection circuit 43 via the signal line 109, and uses the direction value to update the current contents to the coordinate values of a new trace point corresponding to the direction.

A comparison circuit 44 in the edge trace section 4 obtains the coordinate value of the trace start point from the start point register 41 via the signal line 112, and obtains the coordinate value of the current trace point from the signal line 112.
11 from the current point register 42;
The two values are compared, and if they match, a match signal is sent, and if they don't match, a mismatch signal is sent to the control unit 1 through the signal line 113.

The control unit 1 checks the signal line 113, and if there is a mismatch signal, sends a trace signal to the ivW circuit 3 again, causing the above operation to be executed again. The trace point is a closed loop (
After going around the iG area and returning, the comparator circuit 44 provides a coincidence signal to the control unit 1 via the signal line 113. The 1-chi control unit 1 detects this and calculates the area of the closed loop region and each moment. The information processing device is notified of this through the signal line 103, and is inputted.

According to the above explanation, if the moment calculation circuit of the present invention is used, it is not necessary to perform rask scanning and accumulate the contribution to the moment of each pixel included in the closed loop region, which is calculated from the coordinate value of that pixel. , even if other closed loop regions are complicated, there is no need to separate them, and 1
; 11 The edges of the loop region can be traced once and the moment of the closed loop region can be simply calculated.

In the above explanation, the trace starting point is the top point of the area circle, the trace direction is clockwise, and the correspondence between the same trace and the sign of the integration is positive in the X-axis direction.
Although the explanation is given as negative when the direction is negative, this is not limited to the above. Generally, the trace start point can be any point on the edge, the trace direction can be counterclockwise, and the relationship between the trace direction and the sign of the integration is NuiJ response may be determined to be positive when projected onto an arbitrary straight line in a certain direction (positive or negative) and negative when projected in the opposite direction. If the integration result is negative (11), the absolute null J value may be output.

Drawing 11? j Simple cost, Ming 1st section 1 is a diagram showing the closed loop region in the bit pattern,
FIG. 2 is a block diagram showing one embodiment of Kinoi IIll-1.

In the figure, 1...control unit, 2...pattern memory, 3...ILAV circuit, 4...edge trace unit, 5...area accumulator, 6...moment 1- Accumulator group, 41...Start point register, 42...
-Current point register, 43... Direction detection circuit, 44... Comparison circuit.

Claims (1)

[Claims] 1. A pattern memory for storing a bit pattern obtained by scanning a drawing, etc.; 1. A readout circuit that controls writing to and reading from the pattern memory; an edge trace section that traces the edge of a closed loop region in a bit pattern, and one or A moment calculation circuit comprising a plurality of moment accumulators and a control section for controlling each of the circuits, and calculating a moment in a closed loop region. 2. A pattern memory for storing bit patterns obtained by scanning drawings, etc., a write/read circuit that controls writing to and reading from the pattern memory, and edges of closed loop regions in the bit patterns stored in the pattern memory. an edge trace section that traces the trace point, an area accumulator that obtains the distance from the reference line from the current position 1μ coordinates of the trace point given by the edge trace section and integrates it with a sign determined by the trace direction; Calculate the cumulative moment value from the coordinates of the current position of the point,
A moment comprising one or more moment accumulation units 8 that are accumulated according to a sign determined by a trace direction, and a control unit for controlling each of the circuits, and calculating the area and moment of a closed loop region. Calculation circuit.