JPH11355612A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform an emphasis processing so as to make the disturbance of the edge part of images inconspicuous regardless of the shape and/or picture element array of sub pixels on a display device display surface. SOLUTION: Information relating to the shape and picture element array of the sub pixels of a display device 10 is inputted to a processing method setting part 22. The processing method setting part 22 detects the direction of the edge component of input images, makes a signal processing part 24 perform a signal processing for emphasizing the edge component in the case that the direction with the continuity of the picture element array and the direction of the edge component are the same and makes the signal processing part 24 perform the signal processing for not emphasizing the edge component or performing the emphasis processing at an emphasis degree lower than the abovementioned case when they are not the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image display device, and more particularly, to an image display device capable of performing image enhancement processing so that disturbance of an edge portion of a display image is not noticeable.

[0002]

2. Description of the Related Art It is well known that a CRT, an LCD (liquid crystal), an organic EL or the like is used as a display device for displaying image information as a visible image. When color display is performed using these display devices, display is performed by pixels formed by a combination of three primary colors of red (R), green (G), and blue (B). For example, for a CRT,
As a color picture tube, a tube using a shadow mask is currently most frequently used, and a tube using an aperture grill (typically, a Trinitron tube of Sony Corporation) is also used.

FIG. 3 is a diagram showing the basic structure of a CRT.
Consists of a phosphor screen coated with phosphors of R, G, and B colors on a panel glass, a shadow mask with a large number of holes through which electron beams pass, and an electron gun mount for forming electron beams of three colors. Have been. The three-color phosphor screen is divided into a dot pattern in which round dots are arranged in a regular triangle (FIG. 3A), and a strip pattern in which rectangles are arranged in the long side direction (FIG. 3). (B)) and three types of stripes (FIG. 3 (c)) in which rectangular ones are arranged in the longer side direction. The arrangement (pixel arrangement) of the set (pixel array) of the phosphors (sub-pixels) of the three colors RGB is arranged in a pattern arrangement (FIG. 4 (a)) that is continuous in an oblique direction, and in a strip form. Are formed in a pattern arrangement (FIG. 4 (b)) which is continuous in the oblique direction and the vertical direction, and stripes are formed in a pattern arrangement (FIG. 4 (c)) which is respectively continuous in the vertical and horizontal directions. It should be noted that, in the case of a dot, each sub-pixel is also arranged in an oblique direction (FIG. 4A), and in the case of a stripe, each of the sub-pixels is also arranged continuously in a vertical and horizontal direction (FIG. 4A). 4 (c)).

The shape of the hole in the shadow mask is circular (see FIG. 3).
(A)), a slot type (FIG. 3 (b)), and a blind grid type (FIG. 4 (c)) are typical. The blind grid type shadow mask is called an aperture grill. This shadow mask is a thin iron plate attached to the front of the phosphor screen. The holes formed in the mask are regularly arranged at a predetermined pitch, and each hole corresponds to one set of RGB three color phosphors. .

A three-color electron beam array has a delta array (FIG. 3A) in which the cross sections of three electron beams form a regular triangle, and a cross section of three electron beams. There is an in-line arrangement (FIGS. 3B and 3C) arranged so as to be aligned in a horizontal or vertical line. The three electron beams emitted from the electron gun are deflected so as to scan the entire surface of the phosphor screen. However, since each electron beam is blocked by the shadow mask, the electron beams reach the phosphor screen only when passing through the holes. Strike only the phosphor of the color corresponding to. Each electron beam is intensity-modulated by a color signal, and each set of RGB phosphors emits light according to the intensity of the color signal, so that a color image is displayed as a visible image. here,
The color signal that modulates the intensity of each electron beam is a conventional RGB signal.
Generally, similar signal processing is performed irrespective of the color separation pattern of the three-color phosphor screen and the pattern arrangement of the pixels.

[0006] Also in LCDs and organic ELs, the display surface is formed with a plurality of (for example, three colors of R, G, and B) sub-pixels, and the display surface is formed of various types like the CRT fluorescent screen. There is a pattern arrangement, and the same color signal processing is applied to the input color signal as well as the CRT regardless of the pattern arrangement.

[0007]

However, if the same signal processing is performed irrespective of the three-color phosphor screen coloring pattern and the pixel pattern arrangement, the edges of the display image will be fine according to the pattern arrangement and the like. Something that can be seen and one that is noticeably disturbed (jagged) come out. In particular, when performing signal processing for enhancing an edge portion of an image, a state in which the edge portion is conspicuous undesirably deteriorates image quality.
For example, when performing scaling processing on an image, if the interpolated pixel is on an oblique edge, the response characteristics (density) of the interpolated pixel may be present even though the pattern arrangement is continuous in the vertical and horizontal directions as shown in FIG. If the emphasis degree is increased, the image becomes a disturbed image with noticeable step-like steps, so that the emphasis degree is not so much increased (FIG. 5C). However, as shown in FIG. In the case where the continuity is present, the edge portion is not disturbed conspicuously, and the oblique edge component can be strengthened (FIG. 5A). Conversely, when the interpolation pixel is at the vertical edge or the horizontal edge, if the pattern arrangement is continuous in the diagonal direction, if the enhancement of the density of the interpolation pixel is increased, the disturbance becomes conspicuous, so the enhancement is not so much enhanced (FIG. 6 (a) and FIG. 7 (a)), when the pattern arrangement has continuity in the vertical and horizontal directions, vertical and horizontal edge components can be strengthened without noticeable edge portion disturbance. 6 (c) and FIG.
(C)). As shown in FIG. 4B, when the pattern arrangement is continuous in the oblique direction and the vertical direction, it exhibits an intermediate property between the two pattern arrangements (FIG. 5).
(B), FIG. 6 (b), FIG. 7 (b)).

The present invention has been made in view of the above circumstances, and it is possible to display beautifully without noticeable edge portion disturbance in a display image, regardless of the three-color phosphor screen coating pattern or pattern arrangement. It is an object of the present invention to provide an image display device capable of performing image enhancement processing as described above.

[0009]

According to the present invention, there is provided an image display apparatus comprising: an image display means for displaying an image by a pixel constituted by a combination of a plurality of subpixels, that is, a display device; The image processing apparatus further includes image processing means for performing a process of enhancing an edge component of an image in a direction in which the shape of the sub-pixels and / or the arrangement of the pixels are continuous according to the arrangement.

The image processing means of the image display device performs processing for enhancing edge components in the oblique direction when the arrangement of pixels is obliquely continuous, or when the arrangement of pixels is vertical. In the case of horizontal continuity, it is desirable to perform processing for enhancing edge components in the vertical and horizontal directions.

Here, the "shape of sub-pixel" means the shape of each sub-pixel itself and the arrangement when combining them. For example, in the case of a CRT,
R, G, and B three-color phosphor screens are separated patterns.
If it is D, it is a display pattern of three colors of R, G and B on the display surface.

"Pixel arrangement" means the arrangement of pixels composed of sub-pixels.

"Process for enhancing the edge component" means a process for displaying an edge portion of a display image sharper, and is used in a contrast enhancement process, a signal process for improving sharpness, and an image scaling process. A process for calculating the density value of the interpolation pixel is a typical one.

[0014]

According to the image display device of the present invention, the shape of sub-pixels and / or the arrangement of pixels can be adjusted according to the following.
Since the process of enhancing the edge component of the image in the direction with the continuity of the shape of the sub-pixel and / or the arrangement of the pixels is performed, it is possible to perform the edge enhancement process suitable for the display device to be used. For example, if the pixel array has oblique continuity, a process of emphasizing the edge components in the oblique direction is performed.If the pixel array has vertical and horizontal continuity, Processing for enhancing edge components in the vertical and horizontal directions can be performed, and the shape and / or shape of sub-pixels of the display device can be improved.
Alternatively, the image enhancement processing can be performed so that the jagged disturbance at the edge portion is not noticeable according to the pixel arrangement.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an image display device according to an embodiment of the present invention.

As shown in FIG. 1, this image display device 1
A processing method setting unit 22 for setting an image processing method in accordance with a display device (image display means) 10 such as a CRT and a shape of sub-pixels and / or an arrangement of pixels on a display surface of the display device 10 and its setting The image processing unit 20 includes a signal processing unit 24 that performs image scaling processing such as enlargement or reduction on the input image data D0 based on the image data D0 and inputs the processed image data D1 to the display device 10.

The processing method setting unit 22 applies the oblique edge detection method used in the interpolation calculation method for obtaining the interpolated image data of the interpolation point proposed by the present applicant in Japanese Patent Application Laid-Open No. 9-265527. , And original image data D0 of four sample points forming a unit cell including interpolation points inside
, The density gradient vector of each sample point in each of the two array directions is obtained separately, and the direction in which the edge portion having a large density difference in the image extends in the two array directions according to the magnitude of the two density gradient vectors. Or the diagonal direction of the unit cell is determined, and only when it is determined that the direction in which the edge portion extends is the diagonal direction, 2 is added.
In accordance with the value of the product of the two density gradient vectors, it is determined which of the two diagonal directions the direction in which the edge portion extends is the diagonal direction (see JP-A-9-265527).

It should be noted that the processing method setting unit 22 may be any unit that can detect an edge portion extending in an oblique direction of an image. (For example, JP-A-4-268975 and JP-A-9-26653 by the present applicant).
No. 1).

The signal processing section 24 performs image scaling processing, and is provided for calculating the density value of an interpolated pixel by applying a processing method particularly suitable for emphasizing oblique edges. When the edge portion extending in the oblique direction is detected by the method setting portion 22 and the pixel array of the display device 10 is continuous in the oblique direction, signal processing for emphasizing the edge portion extending in the oblique direction is performed. In such a case, the processing method can be selected so that the edge portion is not emphasized.

The operation of the image processing apparatus having the above configuration will be described below.

The processing method setting unit 22 obtains a density gradient vector for each of the two arrangement directions of the sample points based on the original image data D0 of the four sample points constituting the unit cell including the interpolation points therein. The direction in which the oblique edge extends is detected based on the density gradient vector.

The processing method setting unit 22 includes a display device in advance.
When information on the shape of sub-pixels and the arrangement of pixels on the display surface of the display device 10 is input and the pixel arrangement of the display device 10 is continuous in an oblique direction as shown in FIG. When the direction in which the oblique edge extends is detected, an instruction is issued to the signal processing unit 24 to emphasize the edge. Further, when the direction in which the oblique edge extends is not detected, that is, when it is determined that the direction in which the edge extends is substantially along one of the two arrangement directions of the sample points, the edge is not emphasized. To the signal processing unit 24.

On the other hand, the arrangement of the pixels of the display device 10 is shown in FIG.
In the case where the signal is continuous in the vertical and horizontal directions as shown in (c), regardless of whether the direction in which the oblique edge extends is detected or not, the signal processing unit 24 does not emphasize the edge.
Give instructions to

The signal processing unit 24 receives a signal from the processing method setting unit 22
When instructed to emphasize the diagonal edge,
The above-described unit cell is divided into two triangular regions having an edge as a boundary, and based on the original image data D0 of three sample points constituting the triangular region on the side including the interpolation point among the two triangular regions, The interpolation image data of the interpolation point is obtained. Where 3
As the interpolation calculation for obtaining the interpolation image data of the interpolation point based on the original image data of two sample points, the interpolation coefficient is linear, the second or higher order (for example, the interpolation coefficient by spline interpolation, etc.), or , May be expressed in various function forms. By using a higher-order interpolation coefficient, the edge portion can be displayed sharper.

On the other hand, when it is instructed not to emphasize the edge portion, the interpolation image data of the interpolation point is converted based on the original image data of the four sample points of the unit cell configured to include the interpolation point inside. Ask.

Thus, the input image data D0
When performing scaling processing on the image, the oblique edge component of the image is detected, and if the pixel array of the display device 10 is continuous in the oblique direction, the oblique edge component of the image is emphasized. Is performed, the image displayed by the display device 10 can have a very sharp edge portion if the pixel array is continuous in the oblique direction, and the pixel array is vertically and horizontally oriented. In this case, the stepped edge portion is not unnaturally enlarged, and the image is displayed as a smooth image with no noticeable disturbance.

In the above description, a diagonal edge component is detected, and if the pixel arrangement of the display device is continuous in the diagonal direction, the diagonal edge component is emphasized. Otherwise, the emphasis processing is not performed. However, when a diagonal edge component is detected, a strong emphasis process is performed if the pixel array of the display device is continuous in an oblique direction, and if the pixel array is continuous in a vertical and horizontal direction. For example, a weak emphasis process may be performed. In changing the intensity of the edge component enhancement processing according to the pixel array of the display device in this manner, interpolation is performed so that edge components in the same direction as the direction in which the pixel array is continuous are emphasized more than edge components in other directions. The coefficient weighting may be changed. Further, for example, the applicant of the present application has disclosed in Japanese Patent Laid-Open No. 9-9342.
No. 6 combines an interpolation method with relatively high sharpness represented by cubic Cubic spline interpolation and an interpolation method with relatively low sharpness represented by cubic B-spline interpolation or linear interpolation A strong emphasis process by an interpolation method with a relatively high sharpness, and a weak emphasis process by an interpolation method with a relatively low sharpness. Alternatively, the weighting coefficient for determining the mixture ratio of the two interpolation methods may be changed so that the edge component in the same direction as the direction in which the pixel arrays are continuous is emphasized more than the edge component in the other direction.

The above description has been given of the image display apparatus 1 using one display device.
For example, as shown in FIG. 2, an image display device 2 in which a plurality of display devices 11 to 13 are network-connected to an image processing unit 26
Can also be applied. In this case, the image display means
Based on the image data D1 output from 26, by inputting in advance to the processing method setting unit 27 to be displayed on which display device, according to the pixel array of the output destination display device in the same manner as described above In this case, the signal processing unit 28 may perform image scaling processing.

In the above description, the diagonal edge component is detected, and if the pixel arrangement of the display device is continuous in the diagonal direction, the diagonal edge component is emphasized. Otherwise, the emphasis processing is not performed. Although the above description has been made, the present invention is not limited to this, and depending on the shape and / or pixel arrangement of the sub-pixel of the display device, the direction of the continuity of the shape and / or pixel arrangement of the sub-pixel. Any type may be used as long as it performs image processing for enhancing the edge components of the image.

For example, when the pixel array of the display device is continuous in the vertical and horizontal directions as shown in FIG. 4C, the vertical and horizontal edge components are detected, and the vertical and horizontal edge components are detected. In such a case, the vertical and horizontal edge components may be emphasized, and otherwise, the emphasis processing may not be performed.

When the pixel array of the display device 10 is continuous in the oblique direction and the vertical direction as shown in FIG. 4B, the direction in which the oblique edge and the vertical edge extend is detected. If a diagonal edge component or a vertical edge component is detected, the diagonal edge component or the vertical edge component may be emphasized, respectively, otherwise, the emphasis processing may not be performed. Note that the pixel array has continuity in the oblique direction, but the shape of the sub-pixel cannot be said to have continuity in the oblique direction. Therefore, the diagonal edge component is emphasized in consideration of the discontinuity in the shape of the sub-pixel. In such a case, it is desirable to keep the degree of emphasis low.

Further, in the above description, an example in which the interpolation image data is obtained in the image scaling processing has been described. However, the present invention is not limited to such an image scaling processing. It can be applied to anything that emphasizes the edges, such as when playing back high-resolution images, such as when playing back high-resolution images, and when you want to observe images in even more detail. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an image display device according to the present invention.

FIG. 2 is a block diagram showing the configuration of another embodiment of the image display device according to the present invention.

FIG. 3 is a diagram (a) for explaining a basic structural diagram of a CRT,
(B), (c)

FIGS. 4A, 4B, and 4C are diagrams for explaining a shape and a pixel arrangement of sub-pixels; FIGS.

FIGS. 5A and 5B show examples of a diagonal edge image.
(C)

FIGS. 6A and 6B show examples of a horizontal edge image.
(C)

FIGS. 7A and 7B show examples of a vertical edge image.
(C)

[Explanation of symbols]

 10-13 Display device (image display means) 20, 26 Image processing means 22, 27 Processing method setting section 24, 28 Signal processing section

Claims (3)

[Claims] 1. An image display means for displaying an image by a pixel formed by a combination of a plurality of sub-pixels, and a shape and / or a shape of the sub-pixel according to a shape of the sub-pixel and / or an arrangement of the pixels. An image display device, comprising: image processing means for performing processing for enhancing an edge component of an image in a direction in which the arrangement of the pixels is continuous. 2. The image processing device according to claim 1, wherein, when the arrangement of the pixels is obliquely continuous, the image processing unit performs a process of enhancing an edge component in an oblique direction. 2. The image display device according to 1. 3. The image processing device according to claim 2, wherein the image processing means performs processing for enhancing edge components in the vertical and horizontal directions when the arrangement of the pixels is continuous in the vertical and horizontal directions. The image display device according to claim 1, wherein: