JPS59180777A - System for rotation processing of graphic data - Google Patents

Abstract

PURPOSE:To improve the speed of rotation processing of graphic data by shifting an entire image arranging area extending from immediately behind a changing point xi to the next changing point xi+1. CONSTITUTION:A changing point calculating section 2 calculates a changing point (xi, yi) where the most suitable approximation is obtained by dots by quantizing a straight line indicating an angle of rotation, and a shift processing section successively finds a section which becomes a shifting unit and a shifting quantity based on the changing point. Shifting in the vertical direction and horizontal direction are performed by combining simultaneous reading out of pX1 bit or 1Xp bit from a two-dimensional memory 4 and simultaneous writing in the shifting location. By performing the shift processing of both vertical and horizontal direction on all data of areas delimited by each xi and yi on the two dimensional memory 4 in this manner, data which are obtained when a prescribed rotating operation is performed on the graphic data of one picture are implemented on the two-dimensional memory 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a rotation processing method for arbitrary graphic data in an image processing system, particularly for 1×p and pxl
The present invention relates to a method for performing high-speed rotation processing of one graphic data using an image memory that can simultaneously access image points in units of .

[Technology background]

Generally, in CAD systems and other image processing systems that use graphic displays.

Display graphics are frequently rotated, and in facsimiles, image data may be rotated to correct skew.

However,9 normally, the amount of image data, that is, the number of dots that make up the screen, is enormous, and complex calculations are performed for coordinate rotation, which increases processing time.
There was a problem with slow response.

[Object and structure of the invention]

An object of the present invention is to provide a method that can perform rotation processing of one graphic data at high speed, and for this purpose, an image memory is used that can read and write a certain number of dot data simultaneously in two row and column directions.

By repeating the operation of simultaneously shifting a plurality of bits by a predetermined length in the row direction or column direction, high-speed rotation processing of two graphic data is performed.

The configuration of the present invention thereby allows O<<, -0<T and Okuj□-o<, with T and S as design parameters.
Store an image array of TxS consisting of image points I (transport-'lJ?1Lo) that are S, and lxp or p
In a word-organized random access memory system that can read from or write to any subarray of
, u1=0) and the point (M, N) that gives the rotation angle, and the change point w6 in the 1M direction is set to 0. <
Assuming B<N, find sequentially from A and B that satisfy M=AxN×B, and find the next change point x6+1 immediately after the change point town.
The entire image array area up to ko-11I is shifted by i+1 bits in the N direction along the rotation, and the first order is yi”Zi.
Immediately after the changing point 11i, the next changing point 11i+1@
9 rotations 2 by shifting the entire image array area at fll*f− by i+1 bits in the M direction along the rotation.
This method is characterized by obtaining a dimensional pattern.

[Embodiments of the invention]

The details of the present invention will be explained below based on examples.

First, the basic principle of figure rotation will be explained.

Shift in the direction at point d*+dzf, and then shift in the horizontal direction by 6
This can be achieved by shifting with 11C2 ma. At this time, the triangle b161 dl and the triangle b2 c2 d2 are similar, and the length of each side, that is, the required shift amount, is approximately proportional to the distance from the center of two rotations α.

Therefore, for all dots in the graphic data.

Rotation of a figure can be obtained by applying horizontal and vertical shifts of size according to the distance from the rotation center and the rotation angle.

In the present invention, the processing time is shortened by performing the above shift processing in units of a plurality of dots.

For this purpose, a two-dimensional memory of the type disclosed in Japanese Patent Publication No. 54-39098 (Memory System for Image Processing: IBM) is used. FIG. 2 shows an example of this type of two-dimensional memory.

By giving a leading position I (t, 3) in the TxS memory space, it is possible to simultaneously access p bits (IXp) in one row direction or p bits (pXl) in one column direction. In this method, bit data representing each image point on the screen is distributed and stored in multiple memory modules using an appropriate method, and when each memory module is given a predetermined address and accessed simultaneously, p bits of data can be stored in multiple memory modules. They are structured so that they can be read and written together.

Figure 3 (αJ, (bl) indicates shift processing for figure rotation in the present invention. In the figure, 1 is a two-dimensional memory.

[π. ), (-t:lI, (-2), (-s)
, and (yO)', C11-)(yz), (y
3) is the two equally spaced points Z6. J, 22. Z3.
and yo, yl, yz, ' represents the integer part of 3, that is, the quantized value.

Figure (α) shows the vertical shift.

Each interval o ~(”o), ((”o)+1) ~(
et), ((t:]+1)~("zl), (["
z)+1) to [x3] data, sail 1.2.
A shift operation of 3 bits %#@*, m & image is being performed. In addition, in the same figure (61, each section O~(V,), ((1/,)+1)~(
1/1), ((yt:)+1)~(s'z),
A shift operation of 0.1.293 bits is performed on each of the data ((yz)+1) to [v3].

The vertical shift is performed by combining the simultaneous reading of p×1 bits shown in FIG. 2 and the simultaneous writing of the read data to a predetermined shift position. Simultaneous reading of 1.times.p bits shown in FIG. 2 and simultaneous writing of the read data to a predetermined shift position are performed in combination.

In this way, by performing vertical and horizontal shift processing on all data in the areas delimited by (-j) and IJj) on the two-dimensional memory, one Data is created when the graphic data on the screen is subjected to a predetermined rotation operation.

The delimiter in shift') (-j), (Yj) is
It is calculated as the change point when the straight line indicating the given rotation angle is quantized and optimally approximated by dots (
(Hereafter referred to as the change point). Therefore, for example, the gentler the inclination, that is, the smaller the rotation angle.

The interval between change points becomes longer.

Figure N'4 is a block diagram of an embodiment of a graphic data rotation processing apparatus according to the present invention. In the figure, reference numeral 2 denotes a change point calculation unit which calculates a change point (-t), [1/j) based on the starting point and end point data of a straight line representing one rotation angle. 3
is a shift processing unit, which sequentially calculates the interval to be the shift unit and the shift amount based on the change points [-j), 1Jj) given from the change point calculation unit 2, accesses the two-dimensional memory 1, and performs the shift. Execute processing.

FIG. 5 (α) and (bl) conceptually show a method for determining the change point [knee i]. First, the starting point (0,0)
and the end point (M, N). Let this be M2S. If IVI<N, + Z ) i
Process by replacing /. The equation of the straight line is given by. Now, as shown in FIG. 5 (α), V is 0.5. 1.5.2.5. ..., (s + 2)
, . . . and the corresponding X-coordinate value is taken, the dots that approximate the straight line change each time the straight line exceeds the quantization threshold, and become 9th order.

y=o: o~(”o) y=1: (”o,:]+1~[x1]v=2:
[x□]+1~[+1+2] u = L: [”i 1) +1~(-j)v
= N: (eN-t)+l ~ M Fang 5 (b
) shows an example of such a dot pattern.

Next, in order to generally calculate [shi], V=(*
+2) is expressed as v4.

Therefore, (z<)=(Mx(<10-))/N. In this explanation, α/b is the quotient, a, l; y'b
shall represent the remainder.

Here, there exists only one set of integers A and B that satisfy si%曽◆會◆Book 11 豐−$M=AN+B (0×B<N). However, the equation for determining 2(-j) is transformed as follows.

(cs) = ((AN+B)X (s+-i))
/'N Here, ¥ = ((%)・2 + Yu4) ×2.

[C) =((A)di +A<) xN0('su1)・2+2+B')/N■
■ is obtained.

Let (AA+A i ) of the 0th term in the above equation be X. X is obtained by adding A to the previous value. That is +i
=O at (A/'2), (=1 at (A/2 +A
), at t = 2 (A, i +A 10A),...
·bawl.

Also, the 0 term (((A/pA)・N+B')・4 10B
* ) is set as R. Here, (A7'z) only takes the value 1 or O, so ((Aη)・N+B) is (N+B)
or (B). If this value is shifted to the right by 1 bit, the effect of multiplying by + can be obtained. This becomes the initial value of R.

Therefore, (1) can be obtained as follows.

Find the quotient A and remainder j)B from ([)M÷N.

+11) Set initial values to X and R:
Let it be X. This is expressed as XguA↑1.

Also, R.

Shift this one bit to the right (multiply by i) and set it. However, due to rounding processing.

When R=0, set R×N, X×X−1.

(Song DO(=1~(N-1) However, if R)N, due to rounding,
．． Put it as R+RN-N.

Next, FIG. 6 shows the entire algorithm for one figure data rotation process when M≧N in this embodiment.

The upper half of the figure shows initialization processing, and the lower half shows shift processing.

Here, let the center of one rotation be ("x, Il) and 9 points A ("z
, 1lt) is pointed to. The rotation angle θ is 1
It is expressed by the following formula.

Further, the off-line diagram shows an example of rotation processing of graphic data 〃Kan〆 according to the nine embodiments. The figure has been rotated by 5.7 degrees in one counterclockwise direction with the lower left corner as the center of rotation.

〔Effect of the invention〕

As described above, according to the present invention, the shift processing for figure rotation is executed simultaneously in units of multiple bits separated by the change point [αt) and (y<), so the processing is faster than in the conventional method. The time can be significantly reduced.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is an explanatory diagram of figure rotation processing by shift. Figure A12 is an explanatory diagram of two-dimensional memory, Figure 3 (α),
(b) is an explanatory diagram of figure rotation processing based on the present invention;
The figure is a configuration diagram of an embodiment of the present invention, Fig. 5 (α) l (b)
6 is an explanatory diagram of a method of calculating a change point, FIG. 6 is an explanatory diagram showing an algorithm of an embodiment of the present invention, and an off-line diagram is a diagram showing an example of figure rotation. In the figure, 1 is a two-dimensional memory, and 2 is a change point calculation unit. 3 represents a shift processing section, (-<), (110 represents a change point. Patent applicant: Fujitsu Ltd.

Claims (1)

[Claims] With p, 'r, and s as design parameters, 04%-o<
T and 0';:, image point I with jWL-o<8
In a word-organized random access memory system that stores an image array of TxS consisting of (j3-o, jm-o) and can read or write from any subarray of IXp or pxi, the image array coordinates (
-, y) center of rotation on (ml ==Q, yt =O)
and the point (M, N) that gives the rotation angle, and sequentially find the change point z4 in the 9M direction from A and B that satisfy M, , iXN + B, and change point z6 The entire image array area from immediately after to the next change point z, +1 is expressed as i
Shift by +1 bit in the N direction along the rotation and
The next change point 11j immediately after the change point ui set as i-Zi
A graphic data rotation processing method characterized in that a one-rotation two-dimensional pattern is obtained by shifting the entire image array area up to +1 by <+1 bits in the M direction along the rotation.