JPH04186288A - Image display method and device - Google Patents

Abstract

PURPOSE:To perform fade-out/fade-in corresponding to any desired color by forming the density data written in a look up table (LUT) into a table, and performing rewriting of the LUT based on the table. CONSTITUTION:An LUT rewriting table 8 stores the density data supplied from a program memory 5. Thereafter, a signal of starting of fade-in/fade-out is outputted from a CPU 1, an LUT controller 9 block-transfer a part of the data of the table 8 to an LUT 3 in a vertical retrace period. When an image is displayed on a CRT 7, the controller 9 transmits the density data which differ from the previous data from the table 8 to the LUT 3 again. Further, the controller 9 repeats such processing until fade-in/fade-out is ended, and can erase an image into a background color, or make the image appear in the reverse process.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an image display method and device,
More specifically, when switching between displayed screens, the current screen is gradually erased over a certain period of time, and then the next screen is gradually made to appear over a certain period of time, so that the screen switching can be done smoothly. The so-called fade-out,
The present invention relates to an image display method and device with a fade-in function.

[Prior Art] The fade-out/fade-in function of an image display device such as a personal computer is achieved by providing a look-up table (hereinafter referred to as LUT) that assigns densities to display data, and using this to perform density conversion (corresponding to display data). This was achieved by successively rewriting the density data set in the LUT using a central processing unit (hereinafter referred to as CPU). This image device, which is disclosed in Japanese Patent Publication No. 167392/1982, will be described below.

FIG. 6 is a block diagram showing the general configuration of the conventional image display device as described above. In the same figure, l is CP
U, 2 is a frame memory as an image memory that stores image data corresponding to each pixel, 3 is an LUT, 4 is a working memory, 5 is a program memory, and 6 is a D/A
(digital/analog) converter, 7 is a CRT (cathode ray tube display).

In FIG. 6, frame memory 2 stores image data for one screen. When image data is read from this frame memory 2 by the CPUI, LUT3
Then, this image data is supplied, an address matching the supplied image data is searched, and the density data stored in advance at this address is outputted to the D/A converter 6.
supply to. The D/A converter 6 converts this digital density data into an analog signal and supplies it to the CRT 7.

As a result, the image becomes CR with the density based on this analog signal.
displayed on the screen of T.

The fade-out function is realized as follows. That is, when at least one vertical period of screen is displayed on the screen of CRT 7, CPtJ4 reads the density data of each address of LUT3, and subtracts the value given as a parameter from this density data to obtain a new value. The density data is written to each address of LUT3 again. Then, the image data is read out from the frame memory 2 again,
The above processing and image display are performed on the new density data of LUT3. At this time, an image whose brightness is lower than that in the previous vertical period is displayed on the screen of the CRT 7.

Thereafter, the fade-out function is realized by repeating this process. Conversely, if the data stored in LUT 3 is increased overall, a fade-in function can be realized.

[Problem to be solved by the invention]

In this conventional technique, the fade-out function is achieved by gradually decreasing the value of the density data set in the LUT 3, and the fade-in function is achieved by gradually increasing the value of the density data. For this reason,
The value of the density data at the end of the fade-out and at the start of the fade-in had to be limited to O (minimum value, that is, black).

On the other hand, in order to realize effective image display by fade-out/fade-in, it is essential to realize fade-out to any desired color and fade-in from any desired color. However, in the conventional technology as mentioned above,
Since the color at the end of the fade-out and at the start of the fade-in is limited to black (density data=0), there is a problem that effective fade-out/fade-in cannot be performed.

An object of the present invention is to solve such problems and to achieve a more effective fade-out/fade-in, such as an image display method and device capable of realizing fade-out to any desired color and fade-in from any desired color. Our goal is to provide the following.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, the density data to be written into the LUT is separately created as a table, and the LUT is rewritten based on the created density data table.

Further, in the present invention, a rewritable concentration data table storage means for storing the concentration data table, and a transfer control means for transferring and controlling writing of any continuous memory area in the concentration data table storage means to the LUT are provided. .

[Effect]

In the present invention, a density data table is created in advance based on a specified fade-out end color or fade-in start color, and consecutive memory areas of the density data table are read and transferred and set in the LUT, and this is repeated. As a result, the data stored in the LUT is sequentially rewritten, and by gradually changing the data in the LUT, a fade-out function of the designated color or a fade-in function from the designated color is realized.

Further, density data is supplied from the program memory based on the specified fade-out end color or fade-in start color and is stored in the density data table storage means. The transfer control means transfers the concentration data at consecutive addresses in the concentration data table storage means to, for example, D
Use the MA controller to transfer blocks directly to the LUT.

The data stored in the LUT is thereby rewritten. By repeating the above processing while gradually changing the area of the density data to be transferred, a fade-out function to a specified color or a fade-in function from a specified color is realized.

(Example) In an example of the present invention, the flow of fade-out processing performed by the CPU is shown in Figure 1, and the flow of fade-in processing is shown in Figure 2.
The hardware configuration for this purpose is shown in FIG. In the following description, the number of data bits per pixel is 8, and the density data at the end of fade-out and at the start of fade-in is c (an arbitrary integer in the range of 0 to 255).

First, LU in fade-out/fade-in processing
The method for rewriting T will be explained. Although FIG. 5 will be explained in detail later, please refer to the hardware configuration in FIG. 5 if necessary.

The first time is a flowchart showing fade-out processing by the CPU. First, the density data at the end of the fade-out is determined as C, and based on this, an LUT rewriting table (hereinafter referred to as rewriting table) is created (first
Figure processing 1).

FIG. 3 is an explanatory diagram of the created rewriting table, and the density data from address 0 to address (c-1) is 0.1. ......, (c-1
), but from address C to address (C±255), all density data is C, and from address (c+256) to address 511, density data is c, (c+l), . . .
..., 255 are written and created.

Next, returning to FIG. 1, the CPU initializes i (i is any integer less than 256) as the density data change amount to 0 (processing 2). Next, it is determined whether the west face display is the beginning of the vertical retrace period (processing 3), and if the beginning is detected, the LUT is rewritten based on the rewriting table (FIG. 3) (processing 4. 5).

FIG. 4 is an explanatory diagram showing the mode of rewriting. That is, from address i of the rewrite table (c+
The density data up to address 1-1) is transferred from address i (in this case, 1=0) to address (c-1) of the LUT from address (c+256-i) to (5
11-i) Density data up to address is LUT address C
The data is written and set from address 255 to address 255, respectively.

Next, returning to FIG. 1, the CPU sets the density data change amount i to i
+n (n is a positive integer) (processing 6). Next, i is determined, and if i is not 256 or more, process 3
Repeat steps from 6 to 6.

As a result, all of the addresses C to 255 of the LUT in FIG. 4 are changed to density data C, and the fade-out to the specified density data C is completed on the screen.

Furthermore, if you want to make a disappearing image appear by fading in, as shown in the flowchart in Figure 2, the density data change amount i is initially set to 255, and the value of 1 is changed every time Process 3 to Process 5 is repeated. , it may be reduced.

This processing operation is basically the same as the fade-out processing, so its explanation will be omitted.

Next, a configuration example of an image display device for realizing the above fade-out/fade-in processing will be described with reference to FIG. 5.

FIG. 5 is a block diagram showing the configuration of an image display device as an embodiment of the present invention. In the same figure, 1 is the CPU
, 2 is a frame memory that stores 8-bit data per pixel, and 3 is an LU where one address is expressed as 8 bits.
T, 5 is program memory, 6 is D/A converter, 7 is C
RT, 8 is an LUT rewrite table (hereinafter referred to as a rewrite table), and 9 is an LUT controller.

In FIG. 5, a rewrite table 8 stores density data supplied from the program memory 5.

After that, when a fade-in/fade-out start signal is output from the CPUI, the LUT controller 9 writes some data of the rewrite table 8 to the LUT during the vertical retrace period.
Transfer block to UT3.

When the image is displayed on the CRT 7, the LUT controller 9 again transfers density data different from the previous one from the rewrite table 8 to the LUT 3.

Then, the LUT controller 9 repeats this process until the end of the fade-in/fade-out.

Other parts are similar to those of the conventional example shown in FIG. This operation will be explained in detail below, focusing on the fade-out process.

First, in FIG. 5, the density data supplied from the program memory 5 is stored in the rewriting table 8. As shown in FIG. The aspect of this rewriting table 8 is as described above with reference to FIG.

Next, when a fade-out start signal is output from the CPUI, the LUT controller 9 sets the density data change amount i to 0.
Initialize to . At this time, the image data stored in the frame memory 2 is
Corresponding concentration data is obtained with UT3 and displayed accordingly.

Next, it is determined whether the display of the image is the beginning of the vertical retrace period, and when the beginning is detected, the LUT controller 9 moves from address i in the rewrite table 8 to (c+
1-1) Store the density data up to address C in the LUT.
from address (C-1), and from address (C±256-1) to (511-i) in rewrite table 8.
) is transferred in blocks at high speed from address C to address 255 of the LtJT without going through the CPUI (for example, using a DAM controller or the like).

This process is repeated while increasing the density data change amount i by n. As a result, the data in LUT3 is gradually changed to C.

Further, the LUT controller 9 determines whether or not i is 256 or more, and if i is not 256 or more, the above process is repeated. Then, when n becomes 255, all the density data in LUT3 become C, and the fade-out to the designated density data is completed.

Furthermore, in order to make a disappearing image appear by fading in, the density data change amount i may be initially set to 255 using the LUT controller 9, and the value of i may be gradually decreased. This processing operation is basically the same as that for fade-out, so its explanation will be omitted.

As described above, by arbitrarily determining the density data at the end of the fade-out and at the start of the fade-in, and changing the settings of the rewrite table accordingly, the fade-out to the specified color and the fade-in from the specified color are executed. can.

〔Effect of the invention〕

As explained above, according to the present invention, in a digital image, fade-out/
This has the effect of realizing a fade-in function and diversifying the functions of the image display device.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing a method for implementing a fade-out according to the present invention, FIG. 2 is a flowchart showing a method for implementing a fade-in according to the present invention, FIG. 3 is an explanatory diagram showing an LUT rewriting table, and FIG. 4 is from an LUT rewriting table. Explanatory diagram showing the mode of data setting to LUT, 5th
FIG. 6 is a block diagram showing an example of a device for performing fade-out/fade-in according to the present invention, and FIG. 6 is a block diagram showing an example of a conventional image display device. Explanation of symbols 1...CPU, 2...Frame memory, 3...L
UT, 5...Program memory, 6...D/A converter, 7...CRT, 8...LUT rewriting table, 9...LUT controller representative Patent attorney Akio Namiki Figure 1 2nd 1'z 2nd 31st 4 LUT % 1 exclusive toe f 11/ 4th ward 5th death j Figure 6

Claims (1)

[Claims] 1. A central processing unit, an image memory in which image data is stored, and a density conversion table that receives image data read from the image memory and outputs density data corresponding to the image data. and a display means for displaying the image data according to the density obtained from the density conversion table, wherein A density data table is provided that stores density data that changes stepwise up to a lighter second density. , by repeating reading stepwise varying density data while shifting the address and writing it into the density conversion table, a certain local area within one screen displayed on the display means is displayed with the specific background color density. Starting from this, the background color density area is gradually applied to the entire screen, and the image is erased by finally turning the entire screen into the background color density area,
An image display method characterized by making an image appear through the reverse process. 2. A central processing unit, an image memory in which image data is stored, a density conversion table that receives image data read from the image memory and outputs density data corresponding to the image data, and a density conversion table that outputs density data corresponding thereto; an image display device comprising: display means for displaying according to the density obtained from the density conversion table; a density data table in which density data that changes over time is stored in a rewritable manner; Starting from displaying a certain local area within one screen displayed on the display means with the specific background color density by repeating reading and transferring data while shifting the address and writing it into the density conversion table. , a density data transfer control means that gradually applies the background color density region to the entire screen, and finally makes the entire screen become the background color density region and erases the image, or makes the image appear through the reverse process; An image display device comprising: