JPH0731497B2 - Image memory input / output control device - Google Patents

Description

The present invention relates to an image memory input / output control device capable of high-speed processing of a rectangular area in an image memory in a graphic CRT display device having an image memory. Regarding

[Conventional technology]

Conventionally, as a display device of this type, for example,
The one shown in the figure is known. In the figure, 1 is an image processing apparatus for processing various images, 2 is an input / output control unit of an image memory, 3 is an image memory, 4 is a display address generating unit, and 5 is display data read from the image memory. Processing part, 6 is CRT monitor, 7 is X and Y coordinates for access, 8
Is an access control signal, 10 is a display X and Y coordinate, 11 is an image memory address, 12 is an image memory control signal, 13 is an image memory data bus, and 14 is CRT display data.

A raster scanning CRT display device having an X, Y orthogonal coordinate system image memory as shown in FIG. 9 generates an X, Y coordinate 7 to be accessed and an access control signal 9 in the image memory 3 by the image processing device 1. And processing the access data 8. CRT monitor display surface 1
5 also has an X, Y Cartesian coordinate system.

As shown in FIG. 10, the image memory 3 is allocated in the same manner as the coordinates of the CRT monitor display surface 15 and has a group of intersections which are equal to or larger than the coordinate intersections of the CRT monitor display surface 15, and each intersection is composed of a storage element. The access (reading / writing) to the image memory 3 is performed in units of a 16-pixel rectangular area having 4 pixels in the X coordinate direction and 4 pixels in the Y coordinate direction, thereby speeding up the process. When the graphic data in the image memory 3 is displayed on the CRT monitor display surface 15, the image memory 3
Are sequentially read out in the direction of 17 in FIG.
The display operation is performed while scanning 5 in the direction 16 in FIG.

The image memory is accessed by a port for the image memory 3 being "RANDOM" (read / write) and X
With "DUAL PORT DYNAMIC RAM", which has two ports that can read one line of data parallel to the coordinates at one time (data transfer cycle) and read pixel data in synchronization with the clock from the outside. When configured, as shown in FIG. 11, one data transfer cycle 21, several refresh cycles 22 and random access during the scan period of one line defined by the horizontal sync signal 18. Generally, the image memory cycle 20 including the cycle 23 (all the remaining cycles) is performed.

FIG. 12 is a block diagram showing an example of a conventional image memory input / output control unit.

First, in the display data transfer cycle 21, the display X and Y coordinates from the display coordinate generator 4 are selected by the XY coordinate selector 29 and supplied to the image memory 3 through the image memory address bus 11. To be done. The occurrence of the data transfer cycle 21 is detected by the horizontal synchronizing signal 18 and controlled by the image memory control unit 33. By the above operation, 1
The display data for lines is latched in the image memory 3,
Pixel data is sent to the display data processing unit 5 in accordance with the horizontal blanking signal 19.

Secondly, in the refresh cycle 22 of the image memory 3, the refresh address generated by the refresh address generator 27 is selected by the X, Y coordinate selector 29.
It is supplied to the image memory 3 through the image memory address bus 11. The occurrence of the refresh cycle 22 is detected by the horizontal synchronizing signal 18 and controlled by the image memory control unit 33. The refresh cycle is the image memory 3
The number of cycles is determined by the refresh time of.

Thirdly, in the random access cycle, when the operation is read, the X and Y coordinates to be accessed by the image processing apparatus 1 are first input to the access XY coordinate register 24. The output of the access X / Y coordinate register 24 is selected by the X / Y coordinate selector 29 and supplied to the image memory 3 through the image memory address bus 11. The read operation is controlled by the image memory control unit 33, and the read image data from the image memory 3 is input to the read register 31 through the image memory data bus 13. This data is taken into the image processing apparatus 1 from the read data register 25 through the access data bus 8. On the other hand, when the operation is writing, the image processing apparatus 1 should access it.
The X and Y coordinates are input to the access X / Y coordinate register 24, and at the same time, the write image data is input to the write data register 26. Access X / Y coordinate register 24
Is selected by the X / Y coordinate selector 29 and supplied to the image memory 3 through the image memory address bus 11. To write image data, access X that should be written
First, the data in the image memory 3 indicated by the Y coordinate register 24 is taken into the read register 31 through the image memory data bus 13. The data in the read register 31 and the data in the write data register 26 are set in
After performing operations such as D "," OR "," EOR ", and" summary writing ", as shown in FIG. 13, the write data is 4 × 4.
In the case of the pixel write data 35, the write data mask circuit 30 does not perform any processing. In the case of the 1-pixel write data 34, the pixel data of the read register 31 is replaced except for the pixels designated by the access X / Y coordinate register 24. , Is written to the image memory 3 via the write register 32.

[Problems to be solved by the invention]

In the graphic CRT display device having the configuration as described above, firstly, as shown in FIG.
A rectangular area on the image memory 3 (clipping area 36)
When writing image data only to the
Only the configuration of 34 and 35 in Fig. 13 can be taken, and the writing area is
A fixed area of 4 pixels each in the X and Y coordinate directions 37
Since it can only be written to, as shown in the enlarged view in FIG. 14, when the clipping area 36 includes only a part of the 4 × 4 pixel area 37, write in 1 pixel units or immediately before writing. Data processing can be performed by the processing device 1 and writing can be performed in units of 4 × 4 pixels, and data writing cannot be performed at high speed.

Secondly, as shown in FIG. 15, when data is transferred from one rectangular area (reading area 38) on the image memory 3 to another rectangular area (writing area 39), like the above clipping area, Boundary data processing in pixel units cannot be performed at high speed.

That is, the above-mentioned image memory access method has a problem that the data processing in the rectangular area in units of pixels cannot be performed at high speed.

Therefore, the present invention does not reduce the processing speed for the data in the rectangular area set in pixel units,
The purpose is to enable high-speed processing.

[Means for solving problems]

A read data selecting means for selecting block data from the block data group in the read rectangular area, in which the coordinate position deviation of the corresponding block in the write rectangular area is added, and a boundary of the write rectangular area in the selected block data. For the block data, write data selecting means is provided which creates block data from the data outside the area and the data in the block area to be written in the image memory, and writes this in the write rectangular area.

[Action]

In two identical rectangular areas in the image memory, when the data in one rectangular area is transferred to a corresponding block in the other rectangular area in units of a block, the writing rectangular area is written from the block data group in the reading rectangular area. Select new block data that takes into account the coordinate shift of the corresponding block in the area, and select the data outside the area and the data in the block area for the block data that includes the boundary of the writing rectangular area. By creating new block data and writing it in the write rectangular area, the data processing of the rectangular area can be performed at high speed.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram for explaining a read rectangular area and a write rectangular area, and FIG. 3 shows 4 × 4 pixel data from 8 × 8 pixel data. FIG. 4 is a block diagram showing a write data selection unit, FIG. 5 is a circuit diagram showing a select circuit for selecting the nth pixel, and FIG.
FIG. 6 is an explanatory diagram for explaining the write data at the boundary, FIG. 7 is a block diagram showing the write data selection unit,
FIG. 8 is a block diagram showing the rectangular area boundary detection unit.

Here, data is read from a certain read rectangular area 44 (corresponding to the read area 38 in FIG. 15) on the image memory 3 as shown in FIG. 2 to a certain write rectangular area 47 (corresponding to the write area 39 in FIG. 15). Will be described as an example.

In the rectangular area coordinate setting unit 40, the read rectangular area 44 as shown in FIG. 2 is set by the upper left point 45 and the lower right point 46, and the write rectangular area 47 is set by the upper left point 48 and the lower right point 49. , The data read from the rectangular area 44 is loaded into the read register 31 in the same procedure as the conventional one shown in FIG.
It is input to the read data selection unit 42 shown in FIG. The selection unit 42 is a circuit that arbitrarily selects 4 × 4 pixel data from data (8 × 8 pixel data) in four adjacent 4 × 4 pixel regions as shown in FIG. The read rectangular area 44 is located at the pixel coordinates of the upper left point 48 of the write rectangular area 47 within the 4 × 4 pixel area.
By adjusting the pixel coordinates of the upper left point 45 in the 4 × 4 pixel area, the pixel coordinates of the read rectangular area 44 and the write rectangular area 45 are used to correct the coordinate deviation in pixel units.

First, the latches 58, 59, 60, 61 in FIG. 4 are each for latching the data in the 4 × 4 pixel area, and it is assumed that all of them are cleared at the beginning, and the upper left point 45 of the read rectangular area and the write rectangle. The lower 2 bits 51, 52, 53, 54 of each X, Y coordinate of the upper left point 48 of the area are input to the 2-bit subtractor 50. Those outputs are converted by the select signal decoder 53 into data select signals according to the truth table as shown in Table 1.

Also, the subtraction result of the X and Y coordinates determines the data storage order to the latches 58, 59, 60 and 61. The subtraction result for the Y coordinate is "0"
If it is larger, at the upper side of the read rectangular area,
Top 2 of 8x8 pixel data as shown in Figure 3
A blank (no data) is inserted into each 4 × 4 pixel data. That is, in FIG. 2, assuming that the Y coordinate of the upper left point 45 of the read rectangular area is "10", but the Y coordinate of the upper left point of the write rectangular area is "11", which is larger than "10". In order to write the data of the Y coordinate "10" to the Y coordinate "11", the data must be read starting from the Y coordinate "11" of the area above the area of
Blank in the top two 4x4 pixel data (no data)
To insert. On the other hand, when the Y coordinate of the upper left point 45 of the read rectangular area is "10" and the Y coordinate of the upper left point 48 of the write rectangular area is "01" as shown in FIG. If the subtraction result for the coordinates is "0" or less, at this time, the data can be read using the coordinate "01", which is one smaller than the Y coordinate "10" of the upper left point 45, as the starting point. It is not necessary to insert a blank (no data) in the 4-pixel data.

Similarly, as shown in FIG. 2, the upper left point of the read rectangular area
The X coordinate of 45 is "01", and the upper left point 4 of the writing rectangular area
When the X coordinate of 8 is “10”, the subtraction result for the X coordinate becomes larger than “0”, and the X coordinate of “0” becomes “0”.
To write 1 "data, the X coordinate of the area is" 11 "
Since the data must be read starting from, a blank (no data) is inserted in the two left 4 × 4 pixel data. If the subtraction result for the X coordinate is "0" or less, it is not necessary to insert a blank (no data) in the two left 4 × 4 pixel data.

Thus, depending on the result of subtraction of the X and Y coordinates,
Blank in the top two 4x4 pixel data (no data)
To create 8 × 8 pixel data.

To explain the above with reference to FIG. 2, as described above, in the case of FIG. 2, the subtraction result of the X coordinate is larger than “0” and the subtraction result of the Y coordinate is “0” or less. A blank (no data) is inserted in the 4 × 4 pixel data of two copies. Therefore, the latch 58 has 4 × 4 pixel data in the area, the latch 59 has 4 × 4 pixel data in the area, the latch 60 has 4 × 4 pixel data in the area, and the latch 61 has 4 × 4 pixel data in the area. By capturing the × 4 pixel data, 8 × 8 pixel data is created with a blank space formed on the left side. And this 8x8 pixel data is
It is supplied to the 8 × 8 → 4 × 4 pixel data selector 62 through 63, 64, 65 and 66. The selector 62 is a group of select circuits shown in FIG. 5, and selects 4 × 4 pixel data designated by the select signal decoder 56 and outputs it from 67. In the case of FIG. 2, the subtraction result of the X coordinate is “11”,
Since the subtraction result of the Y coordinate is "01", S7 is specified in the first table. Therefore, from the data of the X coordinate "11" and the Y coordinate "01" in the 4x4 pixel data of the area of Selection is started and output from 67. X coordinate of this area "1
Since the coordinates of the 4 × 4 pixel data read from the 1 ”, Y coordinate“ 01 ”as the starting point are the same as the coordinates of the write rectangular area, the first Will be made.

The next read of data from the rectangular area 44 is performed in the order of → in FIG.
The data of 58,59 is shifted to the latch 60,61,
From the new 8 × 8 pixel data, Is selected.

Perform these operations to the right edge of the read rectangular area 44,
Sequentially select the write data, then return to the left end again, and in the future, as shown by ,,, in Figure 2, Y
The same operation is performed for the area increased by 4 pixels in the coordinate direction. By repeating this, the write data is sequentially selected up to the 4 × 4 pixel area including the lower right point of the read rectangular area.

Data writing to the rectangular area 47 is performed by "read", "calculation", and "write" operations in the same procedure as in the conventional case shown in FIG. The read register 31 takes in the data read from the write area 47, and thereafter, the read data selection unit 42 causes the arithmetic unit 28 to input this data without performing any processing. Then, the calculation unit 28 selects the read data selection unit 42 from the data in the read rectangular area described above.
The write data created by is calculated and sent to the write data selection unit 43.

As shown in FIG. 6, in the write data selection unit 43, when the write rectangular area includes only a part of pixel data in the 4 × 4 pixel area 37, the write rectangular area of the 4 × 4 pixel area 37 is outside the write rectangular area. The operation of replacing the data with the data read from the write rectangular area is performed. As a result, the writing rectangular area can be set in pixel units in the X and Y coordinate directions. As shown in FIG. 7, the block diagram of the write data selection unit 43 is an aggregate of 2 → 1 selectors 43A to 43Q, and four matrix signals X0 are provided in each of the X and Y coordinate directions.
~ 3, Y0 ~ 3 select operation. This write data select matrix signal is shown in FIG.
It is created by the rectangular area boundary detection unit shown in (b). That is, in the same figure (a), X at the upper left point of the writing rectangular area
The comparator 70 compares the X coordinate 71 of the lower right point with the X coordinate 71 of the lower right point with the comparator 68, and detects whether it is inside, left end or right end with respect to the set X coordinate of the area, and writes. Notify the data select circuit 75. The lower two bits 77 and 78 of the left and right X coordinates and the write signal 76 for only one pixel are also input to the circuit 75, and the write data select signal 79 (X0 ... X3) is output. In Table 2, (a) shows a truth table regarding the X coordinate, and (b) shows a truth table regarding the Y coordinate. Y
Similarly to the X coordinate, the Y coordinate 73 of the lower right point and the Y coordinate 74 of the upper left point of the writing rectangular area are also set for the coordinate as shown in FIG.
The comparator 68 compares the Y-coordinate 72 which is about to be written at present, and detects whether it is inside, the upper end or the lower end with respect to the set Y-coordinate of the area, and the lower two bits 80, 81 of the upper and lower Y-coordinates. And a write signal 76 for only one pixel are input to the write data select circuit 75 to obtain write data select signals 82 (Y0 to Y3).

In this way, the write data that has been processed in pixel units at the boundary of the area by the write data selection unit 43 is written to the image memory 3 via the write register 32.

Although the embodiment has been described above by taking the copy operation as an example in the image memory 3, the clipping operation can be easily realized if it is regarded as one function of the copy operation, and the present invention is variously modified within the scope of the claims. It is possible.

〔The invention's effect〕

As described above, according to the present invention, when data is transferred between two same-shaped rectangular areas in the image memory, the data in the read rectangular area is written in the image memory input / output control circuit as X, Y for the writing rectangular area. Since the read data selection circuit that corrects the positional deviation in the coordinate direction (pixel unit) and the write data selection circuit that creates the write data by selecting the data outside the area and the data within the area at the boundary of the write rectangular area are provided, Even if it is a rectangular area set in pixel units, not only can data be transferred at high speed to improve the transfer speed, but the clipping operation in pixel units in the X and Y coordinate directions can also be performed in the same way. Is brought about.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram for explaining a read rectangular area and a write rectangular area, and FIG. 3 shows 4 × 4 pixel data from 8 × 8 pixel data. FIG. 4 is a block diagram showing a write data selection unit, FIG. 5 is a circuit diagram showing a select circuit for selecting the nth pixel, and FIG.
FIG. 6 is an explanatory diagram for explaining the write data at the boundary, FIG. 7 is a block diagram showing the write data selection unit,
FIG. 8 is a block diagram showing a rectangular area boundary detection unit, FIG. 9 is a block diagram showing a general CRT display device, and FIG. 10 is an explanation for explaining coordinate allocation of image memory and scanning method of CRT monitor. FIG. 11 is an explanatory diagram for explaining the image memory cycle, FIG. 12 is a block diagram showing a conventional example of the image memory input / output control unit, and FIG. 13 is a diagram for explaining the operation of the write data mask circuit. FIG. 14 is an explanatory diagram for explaining the clipping process, and FIG. 15 is an explanatory diagram for explaining the copy process. Reference numeral 1 ... Image processing device, 2 ... Image memory input / output control unit,
3 ... Image memory, 4 ... Display coordinate generation unit, 5 ... Display data processing unit, 6 ... CRT monitor, 24 ... Access X / Y coordinate register, 25 ... Read data register, 26 ... ... Data register for writing, 27 ... Reflection address generator, 29 ... X / Y coordinate selector, 30 ...
… Write data mask circuit, 31… Read register,
32 ... Last register, 33 ... Image memory control unit, 40 ...
… Rectangular area coordinate setting unit, 41 …… Rectangular area boundary detection unit, 42
...... Read data selection unit, 43 …… Write data selection unit, 43A to 43Q, 62 …… Selector, 50 …… 2 bit subtractor, 53 …… Select signal decoder, 58,59,60,61 …… Latch, 68 …… Comparator, 75 …… Write data select circuit.

Claims (1)

[Claims] 1. An image memory input / output control for transferring data in one rectangular area in two rectangular areas having the same shape in an image memory to a corresponding block in another rectangular area in units of a certain block. In the device, read data selecting means for selecting block data from the block data group in the read rectangular area in consideration of the coordinate positional deviation of the corresponding block in the write rectangular area, and read data selecting means of the selected block data in the write rectangular area. For block data including the boundary, create block data from the data outside the area and the data in the block area in the image memory that is about to be written, and write data selection means for writing this in the write rectangular area, An image memory input / output control device comprising: