JP2004118137A - Image display device - Google Patents

Abstract

When an image is enlarged and reduced and displayed at an arbitrary position, display may be disturbed depending on a vertical enlargement / reduction ratio and a vertical display size if a startup time of a filter process is fixed.
A filter activation time control unit for designating the activation time of a vertical filter unit for vertical enlargement / reduction processing and designating the activation time of a horizontal filter unit for horizontal enlargement / reduction processing. 111 is provided, and the activation time of the vertical filter unit 103 is switched according to the vertical enlargement / reduction ratio, and the activation time of the horizontal filter unit 107 is switched according to the vertical display size on the display unit 110.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image display device that performs an image scaling process and displays a scaled image.
[0002]
[Prior art]
Devices are known for vertical or horizontal reduction of images. This device reduces the memory capacity required for image reduction processing and increases the processing speed by using multiple filters to reduce the original image data that is transferred in blocks. It is configured to output the operation result of the pixel position data necessary after reduction while dividing and inputting and outputting the operation result (work data) by each filter (see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2002-150281
[Problems to be solved by the invention]
Now, when performing vertical scaling processing on the image in the vertical filter section, and then performing horizontal scaling processing in the horizontal filter section, and then trying to display the obtained scaled image on the screen, If the startup time of the filter processing is fixed, the display may be disturbed when the reduction ratio in the vertical direction is increased or when an image having a small display size is displayed at the bottom of the screen.
[0005]
An object of the present invention is to improve image display performance without improving the processing performance of a vertical filter unit.
[0006]
[Means for Solving the Problems]
To achieve the above object, an image display device according to the present invention performs a vertical scaling process on an image, a vertical filter unit for generating a vertical scaling image, and an obtained vertical scaling image. , A horizontal filter unit for performing a horizontal scaling process on the image in the first storage unit to generate a horizontal scaled image, A second storage unit for holding the scaled image, a display unit for displaying an image in the second storage unit, and a start time of the vertical filter unit and a start time of the horizontal filter unit. And a filter activation time control unit. The vertical filter unit and the horizontal filter unit are started asynchronously.
[0007]
The filter activation time control unit switches the activation time of the vertical filter unit according to the enlargement / reduction ratio of the vertical enlargement / reduction processing performed by the vertical filter unit. As a result, even when the reduction ratio in the vertical direction is increased, the processing of the horizontal filter unit does not proceed ahead of the vertical filter unit, and the vertical reduction process can be performed without disturbing the display.
[0008]
Further, the filter activation time control unit switches the activation time of the horizontal filter unit according to the vertical display size of the horizontally enlarged / reduced image displayed on the display unit. Thus, even when an image having a small display size is displayed at the bottom of the screen, the data before being displayed is not overwritten by the horizontal filter unit, and display disorder is prevented.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 shows a configuration example of an image display device according to the present invention. The image display device of FIG. 1 performs a vertical scaling process on an input image 101 and holds a vertical filter unit 103 for generating a vertical scaling image 102 and the obtained vertical scaling image 102. A first storage unit 104, a horizontal filter unit 107 for performing a horizontal scaling process on the vertically scaled image 105 of the first storage unit 104, and generating a horizontal scaled image 106. A second storage unit 108 for holding the obtained horizontally enlarged / reduced image 106, a display unit 110 for displaying the horizontally enlarged / reduced image 109 of the second storage unit 108, and a vertical filter unit 103. A filter activation time control unit 111 for designating the activation time and the activation time of the horizontal filter unit 107 is provided.
[0011]
The vertical filter unit 103 is activated once for one input image 101. The horizontal filter unit 107 is activated twice in the first field and the second field for one vertically enlarged / reduced image 105, and performs horizontal enlargement / reduction processing, respectively. Similarly, the display unit 110 is also activated twice, that is, the first field and the second field, and performs display processing respectively.
[0012]
The first storage unit 104 can hold the vertically enlarged / reduced image 102 generated by the vertical filter unit 103 for one frame. Are read in order from. The second storage unit 108 can hold the horizontally enlarged / reduced image 106 generated by the horizontal filter unit 107 for one field, is written in order from the top from the horizontal filter unit 107, and is written from the top from the display unit 110 from the top. Read in order.
[0013]
Here, the maximum size of the input image 101 is 720 horizontal pixels and 480 vertical pixels, and the maximum sizes of the vertically enlarged and reduced images 102 and 105 and the horizontally enlarged and reduced images 106 and 109 are also 720 horizontal and 480 vertical pixels. The enlargement / reduction ratio can be arbitrarily set in the vertical and horizontal directions from 1/4 to 4 times. Further, the image display position on the display unit 110 can be set to an arbitrary position.
[0014]
The processing performance of the vertical filter unit 103 is proportional to the vertical size of the input image 101. When the period of the vertical synchronizing signal (VSYNC) is set to 1.0V, for a 480-pixel vertical size image, it is 1 in 0.9V period. Processing can be performed for the number of frames. Further, the processing amount of the horizontal filter unit 107 is assumed to be proportional to the vertical size of the vertically enlarged / reduced image 105, and an image of 480 pixels in the vertical size can be processed for one field in a 0.5V period. Shall be. Note that the vertical filter unit 103 and the horizontal filter unit 107 operate in a time-division manner, and when they are executed simultaneously, each of them has a half of the processing performance shown above.
[0015]
FIG. 2 shows the relationship between the vertical enlargement / reduction ratio and the activation time of the vertical filter unit 103, and FIG. 3 shows the relationship between the vertical display size and the first and second field activation times of the horizontal filter unit 107, respectively. The filter activation time control unit 111 specifies the activation time of each of the vertical filter unit 103 and the horizontal filter unit 107 according to FIGS. When the vertical enlargement ratio is between 4 × and 1 ×, the vertical filter unit 103 is activated at 0.4V. During the 0.5 V period, the vertical filter unit 103 operates alone, and during the subsequent 0.8 V period, the vertical filter unit 103 and the horizontal filter unit 107 operate in a time sharing manner. When the vertical enlargement ratio is less than 1 to 3/4, the vertical filter unit 103 is activated at 0.3V. In the 0.6 V period, the vertical filter unit 103 operates alone, and in the subsequent 0.6 V period, the vertical filter unit 103 and the horizontal filter unit 107 operate in a time sharing manner. When the vertical magnification is less than 3/4 to 1/2, the vertical filter unit 103 is activated at 0.2V. In the 0.7 V period, the vertical filter unit 103 operates alone, and in the subsequent 0.4 V period, the vertical filter unit 103 and the horizontal filter unit 107 operate in a time sharing manner. When the vertical enlargement ratio is less than 1/2 times to 1/4 times, the vertical filter unit 103 is activated at 0.1V. During the subsequent 0.2 V period, the vertical filter unit 103 and the horizontal filter unit 107 operate in a time-division manner.
[0016]
FIG. 4 shows one operation example of the image display device of FIG. As shown in FIG. 4, the image display device operates periodically, and its cycle is 2.0V. In this example, it is assumed that the input image 101 having 720 horizontal pixels and 480 vertical pixels is displayed in the center of the screen at 1 × in the vertical direction and 1 × in the horizontal direction. The vertical filter unit 103 is activated to 0.4 V according to FIG. According to FIG. 3, the horizontal filter unit 107 activates the horizontal enlargement / reduction processing of the first field at 0.0V and the horizontal enlargement / reduction processing of the second field at 0.9V.
[0017]
FIGS. 5A and 5B show a reading / writing process (first and second fields) of the first storage unit 104 corresponding to the operation example of FIG. The horizontal axis is time, and the vertical axis is the vertical position of the vertically enlarged and reduced images 102 and 105. The solid line indicates writing by the vertical filter unit 103, and the dotted line indicates reading by the horizontal filter unit 107. In both FIG. 5A and FIG. 5B, the reading does not pass the writing, so that the horizontal filter unit 107 does not perform the horizontal enlargement / reduction processing on the erroneous data.
[0018]
FIG. 6 shows a reading / writing process of the second storage unit 108 corresponding to the operation example of FIG. The horizontal axis is time, and the vertical axis is the vertical position of the horizontally enlarged and reduced images 106 and 109. Solid lines indicate writing by the horizontal filter unit 107, and dotted lines indicate reading by the display unit 110. According to FIG. 6, the reading does not overtake the writing, so that the display unit 110 does not display erroneous data.
[0019]
FIG. 7 shows another operation example of the image display device of FIG. In this example, the input image 101 having 720 horizontal pixels and 480 vertical pixels is reduced by a factor of 1/4 in the vertical direction and 1/4 in the horizontal direction. It is assumed that a pixel image is displayed. The vertical filter unit 103 is activated to 0.1 V according to FIG. According to FIG. 3, the horizontal filter unit 107 activates the horizontal enlargement / reduction processing of the first field at 0.0V and the horizontal enlargement / reduction processing of the second field at 0.9V.
[0020]
FIGS. 8A and 8B show a reading / writing process (first and second fields) of the first storage unit 104 corresponding to the operation example of FIG. The horizontal axis is time, and the vertical axis is the vertical position of the vertically enlarged and reduced images 102 and 105. The solid line indicates writing by the vertical filter unit 103, and the dotted line indicates reading by the horizontal filter unit 107. 8A and 8B, the reading does not pass the writing, so that the horizontal filter unit 107 does not perform the horizontal enlargement / reduction processing on the erroneous data.
[0021]
On the other hand, the alternate long and short dash line in FIGS. 8A and 8B indicates the first storage by the vertical filter unit 103 when the activation time of the vertical filter unit 103 is set to 0.4 V as in the example of FIG. The writing to the unit 104 is shown. In this case, as can be seen from the intersection of the alternate long and short dash line and the dotted line in FIG. The horizontal filter 107 reads out the data before the vertical filter 103 writes, and performs the scaling process. Therefore, an erroneous image is finally displayed, which leads to display disorder. However, according to the present invention, since the vertical filter unit 103 is activated to 0.1 V according to FIG. 2 as described above, display disturbance does not occur.
[0022]
FIG. 9 shows a reading / writing process of the second storage unit 108 corresponding to the operation example of FIG. The horizontal axis is time, and the vertical axis is the vertical position of the horizontally enlarged and reduced images 106 and 109. Solid lines indicate writing by the horizontal filter unit 107, and dotted lines indicate reading by the display unit 110. According to FIG. 9, the reading does not overtake the writing, so that the display unit 110 does not display erroneous data.
[0023]
FIG. 10 shows still another operation example of the image display device of FIG. In this example, it is assumed that the input image 101 having 90 pixels horizontally and 60 pixels vertically is displayed at the bottom of the screen at 1 × in the vertical direction and 1 × in the horizontal direction. The vertical filter unit 103 is activated to 0.4 V according to FIG. According to FIG. 3, the horizontal filter unit 107 activates the horizontal enlargement / reduction processing of the first field at 0.0V and the horizontal enlargement / reduction processing of the second field at 0.0V.
[0024]
FIGS. 11A and 11B show a reading / writing process (first and second fields) of the first storage unit 104 corresponding to the operation example of FIG. The horizontal axis is time, and the vertical axis is the vertical position of the vertically enlarged and reduced images 102 and 105. The solid line indicates writing by the vertical filter unit 103, and the dotted line indicates reading by the horizontal filter unit 107. In either of FIG. 11A and FIG. 11B, the reading does not pass the writing, so that the horizontal filter unit 107 does not perform the horizontal enlargement / reduction processing on the erroneous data.
[0025]
FIG. 12 shows a reading / writing process of the second storage unit 108 corresponding to the operation example of FIG. The horizontal axis is time, and the vertical axis is the vertical position of the horizontally enlarged and reduced images 106 and 109. Solid lines indicate writing by the horizontal filter unit 107, and dotted lines indicate reading by the display unit 110. According to FIG. 12, the reading does not overtake the writing, so that the display unit 110 does not display erroneous data.
[0026]
On the other hand, the alternate long and short dash line in FIG. 12 indicates that writing to the second storage unit 108 by the horizontal filter unit 107 when the second field activation time of the horizontal filter unit 107 is 0.9 V as in the example of FIG. Is shown. In this case, as can be seen from the intersection of the alternate long and short dash line and the dotted line in FIG. Is overwritten by the horizontal filter unit 107. Therefore, an erroneous image is displayed, leading to display disorder. However, according to the present invention, the second field processing of the horizontal filter unit 107 is activated to 0.0 V according to FIG. 3 as described above, so that display disturbance does not occur.
[0027]
【The invention's effect】
As described above, according to the present invention, the start time of the vertical filter process and the start time of the horizontal filter process are controlled in accordance with the value of the vertical enlargement / reduction ratio and the value of the vertical display size, respectively. Can be scaled to an arbitrary size and displayed at an arbitrary position.
[0028]
Thus, the image display performance can be improved without improving the processing performance of the vertical filter unit, so that significant effects can be obtained in both cost and function.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of an image display device according to the present invention.
FIG. 2 is a diagram illustrating a relationship between a vertical enlargement / reduction ratio and a startup time of a vertical filter unit in the image display device of FIG. 1;
FIG. 3 is a diagram illustrating a relationship between a vertical display size and first and second field activation times of a horizontal filter unit in the image display device of FIG. 1;
FIG. 4 is a timing chart showing one operation example of the image display device of FIG. 1;
FIGS. 5A and 5B are timing charts showing a reading / writing process of a first storage unit in FIG. 1 corresponding to the operation example of FIG. 4;
6 is a timing chart illustrating a reading / writing process of a second storage unit in FIG. 1 corresponding to the operation example of FIG. 4;
FIG. 7 is a timing chart showing another operation example of the image display device of FIG. 1;
8A and 8B are timing charts showing a reading / writing process of a first storage unit in FIG. 1 corresponding to the operation example of FIG. 7;
9 is a timing chart illustrating a reading / writing process of a second storage unit in FIG. 1 corresponding to the operation example of FIG. 7;
FIG. 10 is a timing chart showing still another operation example of the image display device of FIG. 1;
FIGS. 11A and 11B are timing charts showing a reading / writing process of a first storage unit in FIG. 1 corresponding to the operation example of FIG. 10;
12 is a timing chart illustrating a reading / writing process of a second storage unit in FIG. 1 corresponding to the operation example of FIG. 10;
[Explanation of symbols]
101 input image 102 vertical scaled image 103 vertical filter unit 104 first storage unit 105 vertical scaled image 106 horizontal scaled image 107 horizontal filter unit 108 second storage unit 109 horizontal scaled image 110 display unit 111 filter activation time Control unit

Claims (3)

A vertical filter unit for performing a vertical scaling process on the image to generate a vertical scaled image;
A first storage unit for holding the vertically scaled image;
A horizontal filter unit for performing a horizontal enlargement / reduction process on the image in the first storage unit and generating a horizontal enlargement / reduction image;
A second storage unit for holding the horizontally scaled image;
A display unit for displaying an image in the second storage unit;
An image display device comprising: a filter activation time control unit for designating an activation time of the vertical filter unit and an activation time of the horizontal filter unit. The image display device according to claim 1,
The image display device, wherein the filter activation time control unit switches the activation time of the vertical filter unit according to an enlargement / reduction ratio of vertical enlargement / reduction processing performed by the vertical filter unit. The image display device according to claim 1,
The image display device, wherein the filter activation time control unit switches the activation time of the horizontal filter unit according to a vertical display size of the horizontal enlarged / reduced image displayed on the display unit.

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