JP3267256B2 - Image display processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display processing apparatus, and more particularly, to an image display processing apparatus that expands and displays compressed moving image data.

[0002]

2. Description of the Related Art When a computer decodes compressed moving image data and displays the decoded moving image data on a display device, the compressed moving image data is expanded by an image decoding unit, and pixels suitable for the display format and display resolution of the computer are used. The process of converting into a number is performed.

In general, moving image display formats include:
The YUV format is used. In the YUV format, the ratio of the color difference signals U and V to the luminance signal Y (sampling ratio, luminance signal Y included in one horizontal line)
And the color difference signals U and V).
V4: 2: 0, YUV 4: 2: 2, and YUV 4: 4: 4. For example, YUV 4: 2:
The 0 format is a format in which display speed is prioritized over image quality, while the YUV 4: 4: 4 format is a format in which image quality is prioritized over display speed.

FIG. 2 schematically shows a typical display format, in which YUV4: 2: 0 and YUV4:
It is a figure explaining the display format of 2: 2 and YUV 4: 4: 4, respectively.

Referring to FIG. 2, YU per four pixels
In the V4: 2: 0 format, Y has four pixels, and U and V each have one pixel. Y, U and V are each 8
Since each bit is provided, the number of bits per pixel is 12 (12 bits / pixel). Similarly, YUV4:
In the 2: 2 format, since Y has 4 pixels and U and V each have 2 pixels, 16 bits / pixel and YUV
In the 4: 4: 4 format, each of Y, U, and V has four pixels, and thus has a data amount of 24 bits / pixel. As the amount of data per pixel increases, the display speed decreases but the image quality improves.

[0006]

However, in the conventional image processing apparatus, when the load on the computer is heavy, when converting to the YUV 4: 2: 2 or YUV 4: 4: 4 format, the processing time of one frame is reduced. It takes more than 1/30 second, resulting in dropped display frames and the like.

[0007] As an image data conversion system,
For example, in Japanese Patent Application Laid-Open No. Hei 7-143475, image data input from each client is stored in a storage device, and when another client accesses the image data, the image data conversion device uses the display resolution and display of the client. A configuration is disclosed in which conversion processing is performed on data conforming to the system and color system, and image data is supplied to a client. However, the system described in the above publication makes it possible to share image data between clients having different display resolutions, display methods, and color systems.
No consideration is given to dynamically switching the color system appropriately in accordance with the fluctuation of the processing load of one client computer.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to appropriately select a display format suitable for a computer processing load that changes every moment from a plurality of display formats. Accordingly, an object of the present invention is to provide an image display processing device capable of displaying a moving image smoothly and with good image quality.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a means for measuring a load state of a computer when displaying a moving image as an image, and switching a display format in conformity with the measured load state. Means for displaying the information.

[0010]

Embodiments of the present invention will be described. The present invention provides a means for measuring the time required for decoding and displaying one frame of moving image data, and comparing and determining the measured time with a predetermined threshold. Means for selecting any of the display format conversion means in units of frames.
The display format is switched according to the load status of the computer. As described above, the load on the computer is determined based on the time required for image display in one frame, and the display format is switched according to the magnitude of the load. When the load is light, image display with emphasis on image quality is performed. When the load is light, it is possible to perform image display that emphasizes the display speed.

In an image display processing apparatus according to the present invention, in a preferred embodiment, referring to FIG.
Is MPEG2 (Moving Picture Coding Experts
Group 2) The moving image data 11 compressed by the method or the like is stored. The compressed moving image data 11 is decoded by the image decoding processing unit 22. The decoded image includes luminance information Y and color difference information U and V.

When this image information is actually displayed on a display device, a conversion process to another display format is required. There are a plurality of display formats, each of which differs in image quality and display speed.

When converting image information into a display format, the display time acquisition processing section 23 acquires the time required to display one frame, and from this time, determines the load on the computer and displays the image. Dynamically switch formats.

Normally, when the computer load is small in the YUV 4: 2: 2 format and there is room for processing, the YUV 4: 4: 4 format in which image quality is prioritized, the computer load is large, and frames may be dropped. At the time, the display is converted to the display speed priority YUV 4: 2: 0 format.

The display format-converted image data is transferred to the frame data buffer 27 and displayed on the display device 3.

As described above, by selectively using a plurality of display formats according to the load condition of the computer, when the load on the computer is light, the display is performed with an emphasis on the image quality, and when the load on the computer is heavy, the display speed is emphasized. Can be displayed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of one embodiment of the present invention. Referring to FIG. 1, the present embodiment includes a storage device 1 for storing compressed moving image data, an image data processing device 2 operated by program control, and a display device 3 for displaying image data.

The storage device 1 has moving image data 11 compressed by a compression method such as MPEG2.

The image data processing device 2 includes a compressed data buffer 21 for securing compressed data loaded from the storage device 1, an image decoding processing unit 22 for decoding the compressed moving image data 11, and a one-frame image. Display time acquisition processing unit 23 for acquiring the time required for display with a timer or the like
And YUV to convert to display format giving priority to display speed
A 4: 2: 0 format conversion processing unit 24, a YUV 4: 2: 2 format conversion processing unit 25 for converting to a normal display format, a YUV 4: 4: 4 format conversion processing unit 26 for converting to a display format giving priority to image quality, and display Frame data buffer 27 for storing image data to be
And

The image data decoded by the image data processing device 2 and converted into the selected display format is displayed on the display device 3.

FIG. 3 is a flowchart for explaining the processing of one embodiment of the present invention. The operation of the embodiment of the present invention will be described in detail with reference to FIGS.

Referring to FIG. 1, a storage device 1 stores compressed moving image data 11. The decoded data of the compressed moving image data 11 includes luminance information Y and color difference information U and V, and is reproduced as a moving image by displaying an image of 30 frames per second. When actually displaying a moving image, it is necessary to convert this image data into another display format.

As also mentioned above, referring to FIG.
Per 4 pixels, in YUV 4: 2: 0 format,
Y has 4 pixels, U and V each have 1 pixel,
Since Y, U, and V each have 8 bits, 12 bits / p
ixel, YUV 4: 2: 2 format, 16 bits because Y has 4 pixels and U and V each have 2 pixels.
/ Pixel, YUV 4: 4: 4 format, Y,
Since each of U and V has four pixels, it has a data amount of 24 bits / pixel. Here, the larger the amount of data per pixel, the lower the display speed but the better the image quality.

In one embodiment of the present invention, the display format is dynamically switched in accordance with the load of the computer which performs the image display processing. The data is loaded into the compressed data buffer 21 (step S1).

Next, the compressed moving image data is restored by the image decoding unit 22 (step S1). The restored data includes luminance information Y and color difference information U and V.

Next, the time T required to display one frame is acquired by the display time acquisition processing unit 23. This time T
Is larger than 1/30 second, it becomes impossible to display an image of 30 frames per second, and frame drop occurs.

In one embodiment of the present invention, the time T required to display the previous frame is compared with a predetermined upper threshold A (a value larger than 1/30 second) (step S3).

If T> A (or T and A
Is larger than a predetermined value), there is not enough room in the display processing,
That is, since the display cannot catch up and frame drop occurs, the display format is converted in the YUV 4: 2: 0 format conversion processing unit 24 which has a small data amount and gives priority to the display speed (step S6).

The display time T is compared with a predetermined lower limit threshold value B (a value smaller than 1/30 second), and
If ≤T≤A, conversion is performed by the YUV 4: 2: 2 format conversion processing unit 25, which is a general display format (step S7). On the other hand, when T <B (or when the difference between T and B is smaller than a predetermined value), there is room for computer processing, and YUV 4: 4 which gives priority to image quality even when the data amount is large. : 4 format conversion processing unit 26 converts the image into a high-quality display format (step S8).

When the display format is changed for the previous frame (steps S4, S4 ', S4).
4 "YES), the surface is initialized before the display format is converted (steps S5 and S5).
5 ', S5 ").

The display format-converted image data is stored in the frame buffer 27 (Step S).
9), displayed on the display device 3 (step 1)
0).

[0032]

As described above, according to the present invention,
By configuring multiple display formats to be switched according to the load of display processing on the computer, display with emphasis on image quality can be performed when the load on the computer is light, and display with emphasis on display speed can be performed when the load on the computer is heavy. It has the effect of being able to.

[Brief description of the drawings]

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

FIG. 2 is a schematic diagram for explaining a display format.

FIG. 3 is a flowchart illustrating a process according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 storage device 2 image data processing device 3 display device 21 compressed data buffer 22 image decoding processing unit 23 display time processing unit 24 YUV 4: 2: 0 format conversion processing unit 25 YUV 4: 2: 2 format conversion processing unit 26 YUV 4: 4: 4 format conversion processing unit 27 Frame data buffer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G09G 5/36 G06F 3/14 G09G 5/00 H04N 11/04

Claims (4)

(57) [Claims] 1. A means for measuring the time required for decoding and displaying the moving image data of one frame, and the comparison determination with a predetermined threshold said measurement time, based on the comparison determination result Means for selecting any one of the plurality of display format conversion means on a frame basis, and dynamically changing the display format of the decoded moving image data according to the load condition. Display processing device. 2. A means for decoding the compressed moving image data, and means for measuring the time taken to display the moving image data of one frame, a plurality of conversion means for converting different display formats from one another, wherein Means for comparing and determining the measurement time with a predetermined threshold value, and selecting one of the plurality of conversion means on a frame basis based on the result of the comparison and determination, comprising: An image display processing apparatus characterized in that the selected conversion means converts the data into a display format suitable for the processing load of the apparatus and displays the converted data in accordance with the magnitude of the measurement time. 3. A comparison determination is made as to whether the measured value of the time required for displaying the previous frame is within a range determined by a predetermined upper limit and a lower limit, and when the measured value exceeds the upper limit. The first display format conversion means, which has a small data amount and gives priority to the display speed, is selected. If the data amount is smaller than the lower limit, the second display format conversion means has a large data amount and gives priority to the image quality. selected and converted to the display format of the image quality, when in a range of the minimum and maximum values, according to claim 1 or 2 to select the third display format conversion means in the normal, characterized in that An image display processing device as described in the above. 4. When a measured value of a moving image compressed by the MPEG2 system is smaller than the lower limit, color information is not reduced and the data amount of the luminance signal and the data of the color difference signal are the same. 4: 4 format, when the measured value is larger than the upper limit, the YUV 4: 2: 0 format in which the color information is reduced in half in the vertical and horizontal directions, and when the color information is within the range between the lower limit and the upper limit, 4. The image display processing apparatus according to claim 3 , wherein the color information is converted into a YUV 4: 2: 2 format in which color information is reduced by half in the horizontal direction.