JP3106033B2 - Display control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display control device for displaying image data by interlaced scanning.

[0002]

2. Description of the Related Art Conventionally, CRT displays have been mainly used as computer displays.
Since the T display requires a certain distance (depth) in the thickness direction of the display screen, it is difficult to reduce the size of the entire display device. Therefore, a liquid crystal display (hereinafter, referred to as LCD) has appeared to supplement this point.

At present, there are several types of LCDs, and they are roughly classified into an active matrix type and a simple matrix type. As the active matrix method, a method having a TFT (thin film transistor) for each pixel is often used. Although this method can perform full-color display because it can perform analog gradation display, it has problems that it is expensive and it is difficult to enlarge the screen.

On the other hand, a simple matrix system using a ferroelectric liquid crystal (hereinafter referred to as FLC) or the like is inexpensive and easy to enlarge the screen. Poor. As a technique for compensating for the lack of color expression, halftone display is performed using image processing such as an error diffusion method (hereinafter, referred to as an ED method).

[0005] The ED method is a technique for realizing a halftone display macroscopically by diffusing an error between a color originally desired to be displayed and a color actually displayed to the right and to the right of the pixel of interest. .

[0006]

However, in the case of a display device having a low frame driving frequency, a high-order interlace (multi-interlace) must be used for scanning, so that a vertical connection is required. There is a problem that the processed image data cannot be displayed by the ED method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to display a halftone processed image by the ED method or the like even in a low-frequency drive display device requiring interlace scanning. It is to provide a display control device capable of performing the following.

[0008]

In order to achieve the above object, the present invention provides a data storage means for storing data input from a computer, and a method for storing data stored in the storage means in a predetermined number of line units. Dividing means for dividing the data into one band, scanning means for performing no interlaced scanning within the divided one band and performing interlaced scanning in band units, image processing means for performing image processing on the data in band units, and the image processing means Transfer means for transferring data from the means to the display device.

[0009]

With the above arrangement, even a display device driven at a low frequency functions to display a moving image or a still image by an image processing method for diffusing an error in a downward direction of a line.

[0010]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating a configuration of an information processing system including a display control device according to an embodiment of the present invention and displaying various characters, image information, and the like. In FIG. 1, reference numeral 11 denotes a CPU that controls the entire information processing system, 13 denotes a main memory that stores a program executed by the CPU 11 and is used as a work area when executing the program, and 14 denotes a main memory.
A keyboard for inputting character information such as various characters, control information and the like; 15 a mouse as a pointing device; 16 a key interface for signal connection between the keyboard 14 and the mouse 15 and the information processing system It is.

Reference numeral 17 denotes a LAN (local area network) such as an Ethernet (registered trademark of XEROX) 18 and a LAN interposed between the present information processing system.
Interface, 19 is ROM, SRAM, RS-
It is an input / output device (hereinafter referred to as I / O) having a 232C type interface and the like. It should be noted that various external devices can be connected to the I / O 19.

Reference numerals 20 and 21 denote a hard disk device and a floppy disk device as external storage devices, respectively. Reference numeral 22 denotes a signal connection between the hard disk device 20 and the floppy disk device 21 and the information processing system. It is a disk interface. Reference numeral 23 denotes a printer capable of performing relatively high-resolution recording, such as an ink-jet printer or a laser beam printer.
Is a printer interface for performing signal connection between the printer 23 and the information processing system.

Reference numeral 25 denotes a display device whose display is controlled by a display interface 26 as a display control device according to the present embodiment. Note that 12
Is a system bus for signal connection between the above-mentioned devices, which is composed of a data bus, a control bus and an address bus. In an information processing system including the above-described various devices, a user of the system generally performs an operation while corresponding to various information displayed on the display screen of the display device 25.

That is, external devices connected to the LAN 18 and the I / O 19, characters provided from the keyboard 14, mouse 15, hard disk device 20, and floppy disk device 21, image information, and the like are stored in the main memory 13. Operation information and the like relating to the user's system operation are displayed on the display screen of the display device 25. The user edits information and performs an instruction operation on the system while watching the display. Here, each of the various devices described above constitutes a unit for supplying display information to the display device 25.

FIG. 2 is a block diagram showing the internal configuration of the display interface 26 constituting the information processing system according to this embodiment. Data input from a host computer (not shown) is stored in the frame buffer 262 of the display interface 26, and its output is controlled by the output line control means 265.
The data output from the frame buffer 262 is
One frame of data is divided into several bands, for example, by dividing eight lines into one unit (hereinafter, one unit is referred to as one band), and transferred to the color conversion palette 263 for each of these bands. Is converted to RGB). Then, the binarized image processing means 26 for each band
1 is output to the output I / F 266.
Then, the result is appended to the address in the display device 25 obtained from the output line control means 265 and output to the display device 25.

However, when periodic refresh (scan) data is output from the frame buffer 262, output band data is output, for example, every four bands as shown in FIG. The output of one frame of data is completed in a total of four fields by outputting the band immediately below the band output in step 4 every fourth band. The band to be output in each field may be arbitrarily changed from the above four bands.

The partial rewriting position detecting means 264 shown in FIG. 2 monitors input data from the host computer, detects a rewritten horizontal line, and outputs the rewritten horizontal line.
Give 65 this information. Output line control means 265
Performs a partial rewrite control that preferentially updates a band including the rewritten line. Note that the input of the partial rewrite band data and the periodic input of the refresh band data to the binarized image processing means 261 may be performed asynchronously, or the input of the partial rewrite band data may be performed as shown in FIG. May be convolved with the input of the refresh band data of the nearest field.

Next, the binarized image processing means 261
The halftone processing in this embodiment will be described in detail.
In the present embodiment, the image processing by the ED method is performed in the above-described band unit. However, when the first line of one band is subjected to the ED processing, error data from a line above the first line is not reflected. When the data is displayed on the display device, a discontinuous region as shown in FIG. 7 appears.

Therefore, in this embodiment, in order to solve the above-mentioned problem, image processing according to the flowcharts shown in FIGS. 4 and 5 is performed by the binarized image processing means 261 whose internal configuration is shown in FIG. That is, step S501 in FIG.
When there is a data input, the ED processing circuit 2612 shown in FIG. 3 is converted from the color conversion palette 263 shown in FIG.
When the data in the band unit is input to the
At 2, it is determined whether the data is partial rewrite data. If it is determined that the data is partially rewritten data, the process proceeds to step S5.
Proceed to 03.

Since the beginning of the process is the first line, in step S504, the error data from the line immediately above the first line of the input data is transferred from the error buffer 2614 to the error line buffer 2613 as shown in FIG. Read in. In the subsequent step S505, ED processing of the first line of the rewriting band is performed using this error data, and error data generated in the first line as a result of the processing is stored in the error line buffer 2613.

In step S506, the display data format conversion circuit 2615 converts the data into a format that can be output to the display device 25, and outputs it to the display device 25. And the above processing is 1 in step S507.
This is repeated until it is determined that the processing has been completed for all the lines of the band. When performing the ED process on the second line, the error data generated in the first line is read from the error line buffer 2613 and the ED process is performed, and the error data generated at this time is stored in the error line buffer 2613. .

The same processing is performed for the other lines following these lines, and E of the last line of the rewrite band is changed.
The error data generated during the D processing is stored in the error line buffer 2
If the error data is stored in the error buffer 613, the error data is transferred to the error buffer 2614 and stored in step S508. Then, in step S509, when it is confirmed that the above processing has been completed for all bands to be rewritten, this processing is completed.

On the other hand, when it is determined in step S502 that the input data is not partial rewrite data but periodic refresh data, the processing shown in FIG. 5 is executed. That is, in step S511, the parameters m, k
(M = 0, 1, 2,..., K = 1, 2, 3,...), M is set to 0, and k is set to 1, and the processing of step S513 is skipped as the first processing routine. The processing of steps S514 to S516 is executed. The halftone processing by the binarized image processing means in this routine is the same as the case of the partial rewriting shown in steps S505 to S507 shown in FIG. 4, and the description is omitted here.

If it is determined in step S516 that the processing of all the lines for one band has been completed, step S5
In step 17, whether or not the above-described routine processing has been performed a number of times corresponding to the number obtained by dividing all the lines by n × l (n is the number of interlaces in a normal state where no image processing is performed, and l is the number of lines in one band) Is determined. If the result of the determination is NO, m is incremented by 1 in step S518.

As a result of incrementing the value of m in step S518, this time the determination in step S512 is Y
Since it is ES, the error data of the line immediately above the (nm + k) th band is read from the error buffer 2614 to the error line buffer 2613 in step S513. Then, as described above, steps S514 to S516
Is performed.

In step S519, it is determined whether or not the above processing has been performed n times. If it has not reached n, the parameter is changed in step S520, that is, m = 0, and k is changed. After incrementing by one,
The process returns to step S512 again. As described above, according to the present embodiment, the image data to be processed is subjected to an error for a line above the line to be processed for each of a plurality of bands each including a plurality of lines. The error diffusion process is performed while reflecting the data. At this time, the band including the line in which the data has been rewritten is preferentially updated, so that in a low-frequency drive display device that requires multi-interlaced scanning, the lower line is processed. Moving image by the method of performing image processing by diffusing the error in the direction,
There is an effect that a still image can be displayed. <Modification> Next, as a modification of the above embodiment, another example of halftone processing by the binarized image processing means 261 will be described.

FIG. 9 is a block diagram showing the internal configuration of the binarized image processing means according to this modification. Also, FIG.
FIG. 11 is a flowchart illustrating an intermediate processing procedure according to this modification. In step S901 of FIG. 10, when data is output from the frame buffer 262 (see FIG. 2) in band units, data is output from several lines of the rewrite band. Specifically, as shown in FIGS. 12 and 13, for example, from the first line of the band to be output,
Data is output five lines before and input to the ED processing circuit 2616 shown in FIG.

In step S903, the error data for the lower line generated in the upper line described above is subjected to ED processing while being stored in the error line buffer 2617, and the error data for the lower line generated in the last line of one band is stored. Clears. Then, in step S904, among the data subjected to the ED processing by the ED processing circuit 2616, the data of five lines that have been input extra are output to the output line control circuit 261.
At 8, only one band of data that should be output is output. In step S905, the display data format conversion circuit 2619 converts the data into a format that can be output to the display device, and outputs the data to the display device.

In step S906, it is monitored whether or not the above processing has been completed for all the lines of one band. If the determination here is YES, in step S907, it is determined whether or not the above processing has been completed for all the bands to be rewritten. Be monitored. On the other hand, if it is determined in step S902 that the input data is periodic refresh data, then in step S909, parameters m and k are set in the same manner as in the above embodiment.
As initialization of (m = 0, 1, 2,..., K = 1, 2, 3,...), M is set to 0 and k is set to 1, and step S910 is performed in the same manner as the processing in the embodiment shown in FIG. To S913.

The processing after step S914 is the same as that in the above embodiment, and the description thereof is omitted here. As described above, also in the present modified example having the above configuration, it is possible to prevent the appearance of a discontinuous region when displaying the data subjected to the ED processing for each band on the display device. The present invention may be applied to a system including a plurality of devices or an apparatus including a single device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus.

[0031]

As described above, according to the present invention,
By performing no-interlace scanning in a predetermined order on each band of the image data divided into a plurality of bands, even when high-order interlacing is required for low-frequency driving, vertical lines It is possible to display a moving image or a still image by applying an image processing method that requires the connection of

[Brief description of the drawings]

FIG. 1 is a block diagram of an information processing system including a display control device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an internal configuration of a display interface constituting the information processing system according to the embodiment;

FIG. 3 is a block diagram illustrating a configuration of a binarized image processing unit according to the embodiment.

FIG. 4 is a flowchart illustrating an image processing procedure in the embodiment.

FIG. 5 is a flowchart illustrating an image processing procedure in the embodiment.

FIG. 6 is a conceptual diagram illustrating a scanning order according to the embodiment.

FIG. 7 is a conceptual diagram illustrating a discontinuous region associated with binarized image processing.

FIG. 8 is a conceptual diagram for describing partial rewriting control according to the embodiment.

FIG. 9 is a block diagram illustrating an internal configuration of a binarized image processing unit according to a modification.

FIG. 10 is a flowchart illustrating an image processing procedure according to a modification.

FIG. 11 is a flowchart illustrating an image processing procedure according to a modification.

FIG. 12 is a conceptual diagram for describing image processing in a modified example.

FIG. 13 is a conceptual diagram for describing image processing in a modified example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 CPU 12 System bus 13 Main memory 14 Keyboard 15 Mouse 16 Key interface 17 LAN 18 LAN interface 19 I / O device 20 Hard disk device 21 Floppy disk device 22 Disk interface 23 Printer 24 Printer interface 25 Display device 26 Display interface 261 Binarization Image processing means 262 Frame buffer 263 Color conversion palette 264 Partial rewriting position detection means 265 Output line control means 266 Output I / F 2611 Error data control circuit 2612, 2616 ED processing circuit 2613, 2617 Error line buffer 2614 Error buffer 2615 Display data format Conversion circuit 2618 Output line control circuit 2619 Display data file Matto conversion circuit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-200287 (JP, A) JP-A-4-134421 (JP, A) JP-A-6-118921 (JP, A) JP-A-5-118921 258064 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09G 3/20 G06T 5/00 G09G 3/36 H04N 5/66

Claims (5)

(57) [Claims] A data storage unit configured to store data input from a computer; a division unit configured to divide the data stored in the storage unit into a plurality of bands in units of a predetermined number of lines; Scanning means for performing no interlace scanning and performing interlace scanning in band units, image processing means for performing image processing on the data in band units, and transfer means for transferring data from the image processing means to a display device A display control device characterized by the above-mentioned. 2. The image processing apparatus according to claim 1, further comprising: a unit configured to detect an update position of the input image data; and a unit configured to perform the image processing preferentially on a band corresponding to the update position. 2. The scanning according to claim 1, wherein the scanning of the band is convolved with the scanning of the nearest next field among the scannings according to the scanning order, or is performed asynchronously with the scanning according to the scanning order. Display control device. 3. The display control device according to claim 1, wherein the image processing is processing using an error diffusion method. 4. A first storage means for storing a diffusion error to a lower line generated in each pixel of a horizontal line, and a data stored in the first storage means, A second storage unit for storing the number of stored data, the diffusion error stored in the first storage device is updated each time the image processing is shifted to the next line, and the diffusion error of the last line in each band is updated. When stored, the diffusion error is transferred to the second storage means, and when processing the first horizontal line of each band, the diffusion error is transferred from the second storage means to the first storage means. 4. The display control device according to claim 3, wherein a necessary diffusion error is read out and used for the image processing. 5. When performing the image processing by the error diffusion method for each of the bands, the image tone processing is performed from a line on a certain line from the first horizontal line of the band, and the data after the image processing is processed. 4. The display control device according to claim 3, wherein is output from the first horizontal line of the band.