JPS5952379A - Interpolating device - Google Patents

Abstract

PURPOSE:To speed up drawing by calculating a picture drawing address by an interpolating device that works as a single function interpolating arithmetic unit constituting hardware. CONSTITUTION:The difference DELTAY of the coordinate values between vertexes corresponding to the first picture data is inputted to a DA converter 1 and an analog voltage corresponding to the difference DELTAY of the coordinate values between DA converted vertexes is outputted. The outputted analog voltage is inputted to a resistance ladder 4 through an electronic switch 2 whose connection position is selected and changed by a multiplexer driver 3 to which the difference DELTAX of the coordinate values between the verteses corresponding to the second picture data is inputted. The analog voltage analog processed by the resistance ladder 4 is connected to an AD converter 7 through an electronic switch 5 whose connection position is selected and changed by a multiplexer driver 6 to which the scanning address variable N of a side connecting vertexes is inputted, and supplied to the AD converter 7 as the analog voltage conforming to the connection position of the electronic switch 5.

Description

[Detailed Description of the Invention] 0) Object of the Invention The present invention provides an interpolation device for speeding up drawing when drawing straight lines constituting a two-dimensional or three-dimensional image in a digital image drawing device or the like. In particular, the present invention relates to an interpolation device that calculates an image drawing address at high speed as a single-function interpolation arithmetic machine in which the arithmetic procedure for drawing is converted into firmware or hardware.

(2) Purpose of the Invention The present invention provides a means for accelerating image drawing address calculation using digital-to-analog conversion, analog processing, and analog-to-digital conversion in order to speed up two-dimensional or three-dimensional image drawing. The purpose is to provide.

(31 Contents and disadvantages of conventional examples) In recent years, the so-called computer graphics technology, in which two-dimensional or three-dimensional images are drawn by a computer on a character display according to geometric equations, has been progressing. Fig. 1 is an example of drawing a rectangle. When drawing Figure 1, the values defined in the frame memory of the computer are the vertices A, B, C, and D of the rectangle in Figure
The X and y coordinates of (m (, rA, yA) − (zB
, yB ) t (zClyC) , (xD, yD )
In order to draw this as a rectangle on the character display, it is sufficient to write the vertices and interpolation lines (each side) of the rectangle shown in Figure 941 in the frame memory of the computer at -19.

Here, taking the side AH in FIG. It is defined by converting the solution of the equation of the straight line passing through B into an integer. However, due to the sequential processing ability of computers,
Since there is a large gap between the entire image, especially in the case of a three-dimensional definition image, one screen after the image definition is
It is not surprising that it takes several minutes to tens of minutes for a computer to finish drawing. The points that require calculation time in these drawing operations are mainly linear interpolation between defined points and surface drawing operations based on this.

Generally, in order to speed up the above-mentioned drawing work, the first
2 in the figure] When finding a solution to the equation of a straight line passing through 11 points A and B, the following method is used to obtain a solution using only integer operations that perform real number operations.

Take the 2m vertex and B in FIG. 1 as an example.

nii L Δx”x at the X and y coordinates of vertex A (xA, yA), the X and y coordinates of vertex B (zB, yB)
Define the coordinate value difference ΔX, Δy between the vertices B rA Δy Niji B−yA, and let ΔX be the larger of the absolute fraction of ΔX and the absolute candy of Δy. (△
When X corresponds to △X, in the following formula, all the squares of X correspond to the values of X, and the values of y correspond to the candy of Y. The opposite is true if Δy corresponds to ΔX.

The following will explain the case where △2 corresponds to △X. ), rA
In the variable X that can take the value of Il+ with and rB, N=
Scanning address variable N of the edge connecting the vertex field x−, A
(NLΔX) is defined. Since the side AB is an interpolated straight line between the vertices A and 8, the displacement Y in the y direction of the side connecting the vertices with respect to the scanning address variable is ΔY Y = −N ΔX. In the above formula, since division is involved, the displacement in the y direction Y
is a real number. Therefore, the displacement Y in the y direction is divided into an integer part Ya and a decimal part Yb, ! = Y a + Y b = "-" N △ shall be considered. In this case, ΔY ward x N Y a≧i , '-2-ΔY-N-2・Ya・△X≧△X, @, 2-
ΔYIIN−(2·Y!L+1)ΔX≧0, and a discriminant for determining whether or not the real part Ya of the displacement Y in the y direction is simultaneously increased when N is increased by 1 is obtained. Therefore,
Let the scanning address variable N of the edge connecting m points be a one-by-one increment, and let 2 be the determination result of the integer part Ya of the displacement Y in the y direction corresponding to the scanning address variable N of the edge connecting the vertices. For example, binary values for scanning edges connecting consecutive vertices of X are sequentially determined.

As described above, it is possible to calculate addresses of interpolated pixels without involving real number calculations. Although operations that do not include real number operations are faster than real number operations inside a computer,
Since it is executed by software, it still has the disadvantage of being insufficiently fast.

(4) Means for Solving the Problems In order to solve the above-mentioned drawbacks, the present invention provides ``a digital-to-analog converter in which first digital image data is supplied as an input signal, and the first digital image data is digital-to-analog converted. An input is connected to the output of the digital-to-analog converting means via an analog converting means and a first electronic switch that is selectively switched according to the second digital image data, and the input is connected to the output of the digital-to-analog converting means, A resistor ladder whose output is connected to a second electronic switch that is selectively switched according to the scanning address, and a human power connected to the resistor ladder through the second electronic switch 1, Rrf
Record! 1 digital image data, the second digital image data, and the analog voltage determined by the scanning address are analog-to-digital converted and outputted as an image drawing address. be.

(5) Examples of the invention FIG. 2 is a block diagram showing one embodiment of the present invention.

In order to increase the speed of drawing, the present invention will be described below with reference to an embodiment 1 of an interpolation device that operates as a single-function interpolation arithmetic machine in which the image drawing address calculation procedure is implemented in hardware.

(In the following definitions of signal values, the same symbols as in the conventional example described above are used in the same definition as in the conventional example, so the definitions are omitted.) Input the coordinate value difference ΔY between 1ITffi vertices corresponding to 1 image data,
An analog voltage corresponding to the digital-to-analog converted coordinate value difference ΔY of the vertex 111j is output.

The output analog voltage is applied to the resistor ladder 4 via the electronic switch 2 whose connection position is selectively switched by the multiplexer driver 3 which inputs the coordinate value difference ΔX between the vertices corresponding to the second 1iIiI image data. is input. The terminal width from the terminal T corresponding to the stator contact of the electronic switch 2 to T i +2 is equal to the integer value of the coordinate value difference ΔX between the sequential vertices.

Since the voltage value of the voltage input to the resistance ladder 4 corresponds to the coordinate value difference ΔY between the vertices, the resistance R1 of the resistance ladder 4
If the resistance values of the resistors R1 to Rn are equal, the potential at each intermediate point of the resistor Ri+2 becomes a potential that is linearly proportionally distributed n. The output analog voltage processed by the resistor ladder 4 is connected to an electronic switch 5 whose connection position is selectively switched by a multiplexer driver 6 inputting the scanning address variable N of the side connecting the bait vertices. n1 is connected to the input of the analog-to-digital converter 7, and is supplied to the analog-to-digital converter 7 as an analog voltage according to the connection position of the electronic switch 5. After conversion, a digital image drawing address A corresponding to the scanning address variable N of the edge connecting the vertices is output.

By using positive and negative polarity types for the digital-to-analog converter 1 and the analog-to-digital converter 7, it is possible to draw an image 11U according to the positive or negative slope of the sleeve line at the apex a1j.
11 address calculation value is not necessary.

(6) Effects of the Invention Since the interpolation device according to the present invention has the above-described configuration, the coordinate value differences △X, △Y between the vertices and the scanning address N connecting the sides between the n1゛1 vertices are determined. Since the speed from when the digital image drawing address A is calculated until the digital image drawing address A is calculated is the same as the operating speed of each component, the above-mentioned software performs the sequential calculation judgment and the sequential calculation of the H digital image drawing address A by the top. At the same time, it is not necessary to calculate the digital image drawing address A described in tlTf while incrementing the scanning address N of the edges connecting the vertices by 1, so the scanning of the edges connecting the vertices 1 It has the advantage that it can respond to jump value input of address N without any speed difference, and can calculate fm digital image drawing address A in detail.

[Brief explanation of drawings]

114 is a diagram showing an example of drawing a rectangle, and FIG. 2 is a block diagram showing an embodiment of the present invention. l......Digital meeting analog converter 2...
......Electronic switch 3...Multiplexer driver 4...
......Resistance ladder 5...Electronic switch 6...Multiplexer driver 7...
・・・・・・Analog number digital converter T, l...
・・・・r T I+2 + Tn・・・・Terminal RI equivalent to the stator contact of electronic switch 2,・・・・・・+ Rt +2 + Rn・・・・
··resistance. Patent applicant: Japan Victor Co., Ltd. Procedural amendment January 1, 1988 Patent application No. 162058 2, name of invention interpolation device 3, person making the amendment Relationship with the case Patent applicant address: Yokohama, Kanagawa prefecture 3-12 Moriyamachi, Kannayo-ku, Ichi Name (432) Victor Company of Japan Co., Ltd. Voluntary Amendment 5, Subject of amendment (1) Scope of claims in the specification (2) Detailed description of the invention in the specification 6. Contents of amendment (1) The scope of the claims has been amended as shown in the attached sheet. (2) “:1::t-” from page 2, line 20,
"Rafter display" is corrected to "display device such as graphic display". (3) In the specification, on page 3, line 7, "Ya tractor display" is corrected to "display device such as graphic display." (/I) Figures 1 and 2 of the attached drawings have been corrected as per the attached sheet. Data is supplied as an input signal, and the digital/analog conversion means converts the first digital image data into digital/analog, and the first electronic switch is selectively switched depending on the second digital image data. The input is connected to the output of the analog conversion means, and the output is connected to a second electronic switch which is selectively switched by the scanning address corresponding to the second digital image data. is connected to the resistor ladder via an electronic switch to output an analog voltage determined by the first digital image data, the second digital image data, and the scanning address.
An interpolation device consisting of an analog-to-digital conversion means for digitally converting and outputting as a digital image drawing address. 2-

Claims (1)

[Claims] In a digital image drawing device that draws a two-dimensional or three-dimensional image on a character display or the like, first digital image data is supplied as an input signal, and digital-analog conversion converts the first digital image data from digital to analog. human power is connected to the output of the digital-to-analog converting means through a first electronic switch that is selectively switched according to the second digital image data, and selected according to the scanning address corresponding to the second digital image data. The output is connected to the second electronic switch to be switched, and the input is connected to the 9JIJ2
is connected to the NIF memory resistor via an electronic switch, and converts the analog voltage determined by the first digital image data, the second digital image data, and the scanning address from analog to digital, and converts it into a digital image drawing address. An interpolation device consisting of an output analog-to-digital conversion means.