JPH07175918A - Magnified plotting system - Google Patents

Abstract

PURPOSE:To speed up by siting the same pixel data in plural addresses at the same time when magnified image data is written in the display memory of a bit map system. CONSTITUTION:This system is composed of a display memory 9 composed of two pairs of video RAM groups composed of four video RAM, a plotting control part 7 controlling the connection change of the video RAM corresponding to the magnified instruction from a controller 1, a data control part 6 controlling the transmission timing of plotting data to a display memory 9 and an address generation part 8 generating the siting address of plotting data. In the address within the video RAM and the pixel on a screen, the same X address within a video RAM periodically corresponds to four continuous picture elements in an X direction on the screen and the same Y address of two pairs of video RAM groups alternately corresponds to two picture elements in a Y direction on the screen. The switches alpha, beta and the switch delta of a switch part R2 are operated corresponding to a magnified multiple and the same address can be written at the same address of video RAM which are up to 4X2 at the same time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnified drawing system, and more particularly, to magnified image data written in a display memory holding display data for each pixel in order to display a magnified image on the screen of a display device. Regarding drawing method.

[0002]

2. Description of the Related Art In the conventional enlarged drawing method, when writing enlarged image data to a bit map type display memory that holds display data for each pixel, each one address (one pixel on the display screen) of the display memory Writing process is in progress. That is, in order to display an enlarged image obtained by multiplying the original image by N and M (N and M are integers) in the horizontal (X) and vertical (Y) directions, respectively, one pixel data of the original image is displayed. It is necessary to write to the address of the display memory corresponding to the continuous area of N pixels x M pixels of the screen to create the enlarged image data. At this time, however, the writing is performed for each address of the display memory. The writing process of the same data is repeated N × M times for one pixel of the image.

[0003]

As described above, in the conventional enlarging drawing method, when enlarging drawing by N × M times, N × M write cycles are performed for one pixel of the original image before enlarging. (Writing process count) is required, and there is a problem that the drawing speed is slow. This is configured such that the address of the storage element in the video RAM forming the display memory and the position (address) of the pixel on the display screen correspond in order, and the video RAM writes data of one address in one write cycle. This is because it can only be done.

An object of the present invention is to provide an enlarging drawing method capable of improving the processing speed of enlarging drawing by reducing the number of repetitions required for writing the same data in enlarging drawing.

[0005]

According to a first aspect of the present invention, there is provided an enlarged drawing method for writing enlarged image data in a bit map type display memory which holds display data for each pixel on a display screen. In, the display memory is composed of 2 n-th power video RAMs (n is a positive integer),
The same X (or Y) address in each video RAM cyclically corresponds to 2 n consecutive pixel positions in the X (or Y) direction on the display screen, and one of the video RAMs or It is configured so that the connection can be changed so that the same data is written simultaneously in units of powers of 2 and X,
The video RAM corresponding to the enlargement multiple in the (or Y) direction
RA that changes the connection of the same and writes the same data at the same time
A drawing control unit that controls the number of Ms, a data control unit that controls the order and timing of drawing data that is sent to the display memory by receiving an instruction from the drawing control unit, and a drawing that receives an instruction from the drawing control unit An address generation unit that generates a write address of data and gives it to the display memory is configured.

According to a second aspect of the present invention, in the enlarged drawing method for writing enlarged image data in a bit map type display memory that holds display data for each pixel on a display screen, the display memory is 2n-th video consisting of 2m-th (m is a positive integer) sets of video RAMs each consisting of 2n-th (n is a positive integer) video RAMs and forming each video RAM group Each of the video RAMs in the 2m-th power group of video RAMs has the same X address in the RAM at consecutive 2n pixel positions in the X direction on the display screen in the X direction.
Of the video RAMs each of which has the same Y address periodically corresponds to the 2 m consecutive pixel positions in the Y direction on the display screen, and which connects the video RAM groups and constitutes each video RAM group. The connection can be changed so that the same data can be simultaneously written in units of integer powers of 2 or 1 and the same data can be changed by changing the connection of the video RAM and the video RAM group according to the expansion multiple in the X and Y directions. A drawing control unit for controlling the number of video RAMs for simultaneously writing data, a data control unit for controlling the order and timing of drawing data sent to the display memory in response to an instruction from the drawing control unit, and a drawing control unit An address generation unit that receives an instruction, generates a writing address of drawing data, and gives the writing address to the display memory is configured.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention.

As shown in FIG. 1, the enlargement drawing method of this embodiment holds a bit map type display memory 5 composed of eight video RAMs and original image data to be enlarged and outputs an enlargement instruction. The control device 1, a drawing control unit 3 that controls connection change of the video RAM of the display memory 5 in response to an enlargement instruction from the control device 1, and original image data received from the control device 1 as drawing data to the display memory 5. It is composed of a data control unit 2 for controlling the sending order and timing, and an address generation unit 4 for generating a writing address of drawing data and giving it to the display memory 5.

As shown in the internal configuration diagram of FIG. 1, the display memory 5 is composed of eight video RAMs (video RAM-A to video RAM-H), and the address of the storage element in each video RAM and the display screen. The relationship with the address of each pixel above is such that the same X address of each video RAM periodically corresponds to the X address of consecutive 8 pixels on the display screen. That is, the 8 pixels whose X addresses are 1 to 8 on the display screen are the X addresses 1 of the video RAM-A to the video RAM-H, and the 8 pixels whose pixel X addresses are 9 to 16 are the respective video RAMs. , And the Y address of each pixel and the Y address of each video RAM are in a one-to-one correspondence in order.

Further, a switching unit R1 which operates by a control signal from the drawing control unit 3 is connected between each video RAM and a selector S1 which selects eight video RAMs with a specific 3 bits in the address signal. And switches α, β, γ
Is configured so that a parallel write operation can be performed with a power of 2 as a unit. For normal writing to the display memory 5, the switching unit R1
Each switch α, β, γ is in the illustrated state, and writing is performed only to one of the video RAMs selected by the selector S1 by the address signal. On the other hand, for example, when the image is enlarged twice in the X direction, by operating the four switches α of the switching unit R1, the video RAM-A, the video RAM-B, and the video RAM-C are activated.
And video RAM-D, video RAM-E and video RAM
-F and video RAM-G and video RAM-H are combined, and the same data can be simultaneously written in the same address in two video RAMs.

The data control unit 2 receives the original image data from the control device 1 and outputs the drawing data timing (the number of write cycles) of the drawing data to the display memory 5 in correspondence with the magnification.
To control. This timing control is performed in connection with the connection change of the video RAM in the drawing control unit 3, and when the magnification in the X direction is a power of 1 or a power of 2 (2, 4, 8), 1 write cycle at the time of line writing. The drawing data is updated every time, when the expansion multiples are 3, 5 and 7, it is updated every 3, 5 and 7 write cycles, and when the expansion multiple is 6, it is updated every 3 write cycles. It should be noted that when enlarging and drawing in the Y direction, the cycle of drawing data output during line writing is repeated by the enlarging multiple.

The drawing control unit 3 controls connection change of the video RAM of the display memory 5 in response to an enlargement instruction (enlargement multiple in the X direction) from the control device 1. Expansion factor in X direction is 2
In the case of powers of (2, 4, 8)
Control M to operate in parallel by 2, 4 and 8
When the expansion multiple is 6, two are operated in parallel. The result of the connection change is notified to the data control unit 2 and the address generation unit 4.

The address generation unit 4 receives the address information of the start position on the display screen for displaying the enlarged image from the control device 1, and writes the drawing data by referring to the connection information and the enlargement multiple from the drawing control unit 3. The address of the video RAM to be generated is generated and sent to the display memory.

Now, consider a case where the original image is drawn in the same size without enlargement on the upper left rectangular area of 8 pixels × 4 pixels of the display screen as shown in FIG. 2A. In the case of the normal size drawing, the drawing control unit 3 sets the connection of the switching unit R1 of the display memory 5 to the state of FIG. 1 in which writing is individually performed in each video RAM. The data control unit 2 receives the original image data from the control device 1, first switches the data of 8 pixels in the first line for each write cycle, and sequentially outputs the data as drawing data to the display memory 5. Address generator 4
Generates an address corresponding to the position of a pixel on the display screen, and in the order of video RAM-A, video RAM-B ... video RAM-H, the same address (X
Drawing data is written in address 1 and Y address 1). When the drawing of the first line is completed, the drawing is sequentially performed on the second line, the third line, and the fourth line, similarly to the first line. Therefore, when the enlarged drawing is not performed, 8 shown in FIG.
Drawing of a rectangular area of pixels × 4 pixels is completed in 32 write cycles. Original image data 1
a to 4h, the display screen is displayed as shown in FIG. 2B, and the corresponding data is displayed in each video RAM.
It is stored as shown in (c).

Next, the same 8 pixels × 4 as in the case of FIG.
Consider a case in which the original image of pixels is drawn in the horizontal direction in a rectangular region of 16 pixels × 4 pixels at the upper left of the display screen shown in FIG. When the magnification factor in the horizontal direction is 2, the drawing control unit 3 controls the video RAM-A and the video RAM-B, the video RAM-C and the video RAM-D, the video RAM-E and the video RAM-F, and the video RAM-G.
And a video RAM-H as a set, the four switches α of the switching unit R1 shown in FIG. 1 are switched and connected so that the same drawing data output from the data control unit 2 can be simultaneously written in two video RAMs. To change. Data control unit 2
First, similarly to the case of the normal size drawing, first, the data of 8 pixels in the first line is output as the switching drawing data for each write cycle. The address generator 4 displays the screen shown in FIG.
In order to perform the display as shown in (b), an address corresponding to the position of every other pixel in the X direction is generated and output, and 8 write cycles are performed to 2 addresses of each video RAM as shown in FIG. The drawing data is written as shown in. 1
When the drawing of the line is completed, the drawing of the second line, the third line, and the fourth line is sequentially performed in the same manner as the drawing of the first line. Therefore, when the image is drawn twice in the horizontal direction, the image shown in FIG.
Drawing of the 16 pixel × 4 pixel rectangular area shown in (a) is completed in 32 write cycles, which is the same as in the case of the normal size drawing. That is, it is possible to perform enlarged drawing with half a write cycle of 64 times as compared with the conventional case of writing for each pixel of the display memory 5.

Similarly, when the image is enlarged by a factor of 4 in the horizontal direction, the drawing control unit 3 switches the switches α and β of the switching unit R1 so that the video RAM-A to the video RAM-.
D and video RAM-E to video RAM-H as a set,
The same drawing data can be written in four video RAMs at the same time, and the address generator 4 generates an address corresponding to the position of every four pixels in the X direction. In the case of enlarging eight times in the horizontal direction, by simultaneously switching the switches α, β, γ of the switching unit R1, it becomes possible to simultaneously write to eight video RAMs. When writing in a plurality of video RAMs in parallel and performing enlargement drawing, the write start position of the enlarged image data can be moved only in units of 2, 4 and 8 pixels according to the enlargement magnification. become. However, even if the image is enlarged by a factor of 8, if the two video RAMs are written in parallel, it is possible to move the position in units of two pixels, but it takes four write cycles to write data for one pixel of the original image. It will be.

In the above embodiment, eight video RAMs are periodically associated with eight pixels in the X direction of the display screen, but they may be associated with pixels in the Y direction instead of the X direction.
Similar effects can be obtained by simply changing the horizontal and vertical directions.

FIG. 4 is a block diagram showing the configuration of the second embodiment of the present invention.

As shown in FIG. 4, the enlarged drawing method of the present embodiment uses two sets of video R composed of four video RAMs.
A display memory 9 including an AM group, a drawing control unit 7 that controls connection change of the video RAM of the display memory 9 in response to an enlargement instruction from the control device 1, and a timing of sending drawing data to the display memory 9. The data control unit 6 and the address generation unit 8 that generates the writing address of the drawing data and gives it to the display memory 9.

As shown in FIG. 4, the display memory 9 is composed of two sets of video RAM groups (AD and EH) each consisting of four video RAMs, and has addresses of storage elements in each video RAM. Regarding the relationship with the address of each pixel on the display screen, the same X address in the four video RAMs forming each video RAM group periodically corresponds to the X address of the same continuous four pixels on the display screen. However, the same Y address in each video RAM of the two sets of video RAM groups is connected so as to alternately correspond to the Y addresses of two consecutive pixels on the display screen. That is, a rectangular area of 8 pixels of 4 pixels × 2 pixels on the display screen is configured to correspond to the same address in eight video RAMs.

Further, a switching unit is provided between each video RAM and the selector S2 for selecting the video RAM group by the specific bit in the Y address signal and selecting the video RAM by the specific 2 bits in the X address signal. R2 is connected and 2 or 4 in the X direction can be activated by operating switches α and β.
The parallel writing to the pixels is configured such that the parallel writing to the two pixels in the Y direction can be performed by operating the switch δ. For normal writing to the display memory 9, the switches α, β,
δ is in the illustrated state, and the selector S
Writing is performed only to one of the video RAMs selected in 2. On the other hand, in the case of performing enlarged drawing, the drawing control unit 7 controls the switches α and β according to the enlargement multiple in the X direction, and controls the switch δ according to the enlargement multiple in the Y direction. 2x2 or 4x at the same time
The same data can be written to two video RAMs.

Here, the upper left 4 pixels of the display screen × 2
Consider a case where the original image is drawn to the rectangular area of pixels without enlargement. The drawing control unit 7 sets the switching unit R2 of the display memory 9 to the state shown in FIG. Control device 1
The original image data from is output by switching from the data control unit 6 for each write cycle, and is written in the display memory 9 by one address by the address signal from the address generation unit 8 and the rectangular area of 4 pixels × 2 pixels is Drawing is completed in eight write cycles. As shown in FIG. 5A, the display data of each pixel displayed on the screen is displayed as 1a to 2d.
Then, as shown in FIG. 5B, the data of the first line and the data of the second line are all written to the same address of each video RAM.

Next, the same original image data of 4 pixels × 2 pixels as in the case of FIG. 5 is doubled in both X and Y directions, and 8 pixels × upper left corner of the display screen as shown in FIG. 6A. Consider a case in which a rectangular area of 4 pixels is enlarged and displayed. The drawing control unit 7 switches the four switches α of the switching unit R2 shown in FIG. 4 corresponding to the enlargement factor 2 in the X direction, and further changes the four switches α of the switching unit R2 corresponding to the enlargement factor 2 in the Y direction. Switch the switch δ. With this, 4 video RAs
The same drawing data can be simultaneously written to M (A, B, E, F and C, D, G, H). In this way, FIG.
Drawing is completed in eight write cycles of four pixels for a rectangular area of 8 pixels × 4 pixels shown in (a). Therefore, it is possible to perform enlarged drawing with 32 quarter write cycles as compared with the conventional case of writing for each pixel.

[0025]

As described above, according to the enlarged drawing method of the present invention, the bit map type display memory is constituted by the power of 2 video RAMs, and the pixel array on the display screen and the storage of each video RAM are stored. It is configured such that the relation with the address of the element is set to a periodic repeating relation and, at the same time, the connection of the video RAMs is changed corresponding to the enlargement multiple and the parallel writing can be performed. Therefore, there is an effect that the writing speed at the time of writing the enlarged image data in the display memory for the enlarged drawing can be increased, and it becomes easy to cope with the rapid image change.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is an explanatory diagram of a data storage operation during non-enlarged drawing in the embodiment of FIG.

FIG. 3 is an explanatory diagram of a data storage operation at the time of enlarged drawing in the embodiment of FIG.

FIG. 4 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

5 is an explanatory diagram of a data storage operation at the time of non-enlarged drawing in the embodiment of FIG.

FIG. 6 is an explanatory diagram of a data storage operation during enlarged drawing in the embodiment of FIG.

[Explanation of symbols]

 1 control device 2,6 data control unit 3,7 drawing control unit 4,8 address generation unit 5,9 display memory

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G09G 5/36 G 9471-5G

Claims (2)

[Claims] 1. In an enlarged drawing method for writing enlarged image data in a bit map type display memory that holds display data for each pixel on a display screen, the display memory has a power of 2n (where n is Positive integer) video RAM
And the same X (or Y) address in each video RAM is the consecutive 2n X (or Y) on the display screen.
Direction pixel position periodically, and the video RA
The connection can be changed so that the same data can be simultaneously written in units of M or an integer power of 2, and the connection of the video RAM is changed according to the expansion multiple in the X (or Y) direction. A drawing control unit that controls the number of video RAMs that write the same data at the same time, a data control unit that controls the order and timing of drawing data that is sent to the display memory in response to an instruction from the drawing control unit, and the drawing control unit And an address generation unit for generating a writing address of drawing data and giving it to the display memory. 2. In an enlarged drawing method for writing enlarged image data in a bit map type display memory that holds display data for each pixel on a display screen, the display memory is 2 n-th power (n: Positive integer) video RAM
2 m-th (m is a positive integer) sets of video RAM groups, and the same X address in the 2 n-th video RAMs forming each video RAM group is consecutive 2 on the display screen. At the nth power of X pixel positions in the X direction, the same Y address in each video RAM of the 2m power set of video RAM groups is respectively arranged at the consecutive 2m power of Y pixel positions on the display screen. It is configured to correspond to each other periodically, and the connection of the video RAM groups and the connection of the video RAMs constituting each video RAM group can be changed so as to simultaneously write the same data in units of integer powers of 2 or 1; And a drawing control unit for changing the connection of the video RAM and the video RAM group corresponding to the enlargement multiple in the Y direction and controlling the number of video RAMs for writing the same data at the same time, and an instruction from the drawing control unit. A data control unit that controls the order and timing of drawing data that is sent to the display memory, and an address generation unit that receives an instruction from the drawing control unit, generates a writing address of the drawing data, and gives the writing address to the display memory. Enlarged drawing method characterized by that.