JPH09233383A - Image display device and image input/output system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image input/output system optimizing the picture element structure of an image pickup and a display and the combinations and displaying image data at high speed and displaying image data so that the picture elements may be difficult to be perceived. SOLUTION: An image pickup is performed by an image pickup element 2 having a quandrangle picture element structure in which a delta-array is performed for image pickup elements 2a and a display is performed by an image display device 4 having a hexagonal picture element structure in which a delta-array is performed for display picture elements. The image pickup element 2 having the quandrangle picture element structure of the delta-array has the resistance to the folded distortion caused by the imperfection of an optical filtering, excellently preserves horizontal and vertical components with high visual contrast sensitivity for an original image component and the apprearance of the image is made better. The image display device 11 having the hexagonal picture element structure of the delta-array cuts the unnecessary high frequency caused by the picture element structure of the horizontal component with high contrast sensitivity, lets the frequency go to the oblique direction component with low contrast sensitivity and picture elements are made difficult to be perceived.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input / output system which optimizes a pixel structure in image pickup and display in order to improve image quality when a pixel is easily perceived like a large screen display device, and an image quality control method. The present invention relates to an image display device having an improved pixel structure.

[0002]

2. Description of the Related Art Conventionally, a technique aiming to improve image quality by improving a pixel structure has been performed separately in an image display device and an image pickup device. Here, methods for improving the pixel structure, which have been performed in the image display device and the image pickup device, will be described.

Regarding the image display device, the pixel structure differs depending on the difference in the color mixing method.

As shown in FIG. 14, in an image display device using integral additive color mixing for displaying one color at one pixel position, a delta array in which the line connecting the sampling centers is formed in a Δ shape is known. The Nyquist limit of the delta array is as shown in FIG. 15, and the horizontal resolution is doubled as compared with the commonly used square array. The human visual sense has the spatial anisotropy shown in FIG. 16, and the image quality can be improved by using a delta array that doubles the horizontal resolution at the expense of the diagonal resolution with low contrast sensitivity. it can.

On the other hand, in an image display device using spatial average additive color mixture, such as a CRT, which displays one color at three pixel positions, the RGB delta array (FIG. 17 (a)) and the RGGB square array (FIG. 17) shown in FIG. 17 (b)) is known. Subjective evaluations have shown that the RGB delta array is effective in natural images, and theoretically, its effectiveness is shown by the Nyquist limit isotropic property and a good color mixing effect. The RGGB square array is said to be excellent when the viewing distance is large, because there are many G pixels with high visibility.

In the image pickup apparatus, an image pickup element having a delta array structure shown in FIG. 18 is known. For this reason, excellent image quality can be obtained for the same reason as the delta arrangement in the image display device using the above-described integral additive color mixture.

In general, an image input / output method is widely used in which an image is picked up by a square pixel structure arranged in a square array and displayed by a square pixel structure arranged in a square array. Among the conventional methods for improving the pixel structure, the most effective method is a method in which imaging is performed using a delta-arranged rectangular pixel structure and display is performed using the delta-arranged rectangular pixel structure.

Further, when displaying low-definition image data on an image display device with higher definition than that, one pixel data of the low-definition image data is expanded to a rectangular block in which high-definition pixels are collected. Then, how to make a square array,
A method of interpolating between low-definition pixel data to compensate for the pixel brightness of a portion where no data exists in a high-definition image display device is used.

Further, due to the limitation of communication capacity, the definition is reduced,
In order to reduce the resolution to match the definition of the image display device, there is a method of averaging the luminance within a square block in which square-shaped original pixels are aggregated to obtain low-definition pixel data. .

[0010]

As described above, in the conventional image quality improving method, the pixel structure in image pickup and the pixel structure in display are independently examined, and the image generation process from image pickup to display is considered. Didn't. The problem caused by this will be described by taking a conventional image input / output system as shown in FIG. 19 as an example.

In this system example, the image pickup target 112 is picked up by the image pickup device 112 in which the image pickup pixels 112a are square arrayed as shown in FIG. 19B through the optical system 111, and the picked-up image data is transmitted through the image transmission path 113. 19 (c), the display pixels 114a are sent to the image display device 114 in which the display pixels 114a are arranged in a delta array for display.
It was said that it was presented in 02. Here, it is not a problem because pixels are hardly perceived in a display such as a CRT, but in an image display device in which pixels are easily perceived like a large-screen display, a difference between sampling points at the time of image pickup and at the time of display causes a difference in image quality. It causes deterioration and becomes a big problem. As described above, conventionally, the display pixel structure has been improved regardless of the pixel structure at the time of image capturing.

Further, as described above, the delta array is superior from the Nyquist limit shape. However, since the pixel shape is quadrangular, there are many horizontal and vertical lines with high visual contrast sensitivity, and the pixel is There is a problem that it is easily perceived.

On the other hand, an optical low-pass filter is generally optically inserted for the purpose of removing aliasing distortion caused by sampling during image pickup. But,
Since ideal optical filtering that completely eliminates aliasing distortion is practically impossible, mixing of aliasing distortion into image data is inevitable. Therefore, the resistance of the pixel structure against the aliasing distortion and the resistance of the combination of the pixel structures in the imaging and the display are required.

Further, when low-definition image data is displayed on a higher-definition image display device, the method of enlarging one pixel data into a square block and arranging it in a square arrangement enables high-speed processing. However, there are problems that pixels are easily perceived, suspicious contours are conspicuous, and image quality is very poor.

On the other hand, the method of interpolating between pixel data and compensating for the pixel accuracy of a portion where data does not exist requires a processing time because it calculates a gradient with respect to a neighboring pixel for each pixel, so that real-time processing is required. Requires an expensive high-speed processing system.
In terms of image quality, pixels are hardly perceived, but the edges are flattened, resulting in a blurred image, which is not necessarily excellent. At this time, adaptive processing that leaves edges is conceivable, but it is difficult to save only desired edges, and complicated image processing is required, so
It is difficult to do in real time.

Further, due to the limitation of the communication capacity, the definition is lowered,
The method of averaging the luminance in the square blocks arranged in a square array is a suitable method as it is, in the case of reducing the resolution to match the definition of the image display device, because it can perform real-time processing. However, since the processing is generally performed uniformly regardless of the pixel structure of the image display device, even if the display pixel structure is improved, the effect is reduced in most cases.

An object of the present invention is to solve the problems of the above-mentioned conventional image quality improving method, in order to solve the problem,
By optimizing the combination and the combination thereof, it is possible to provide an image input / output system for displaying a limited amount of image data at high speed and with pixels hardly perceived, and an image display device with pixels hardly perceived. is there.

[0018]

In order to achieve the above object, the image display device according to the first invention of the present invention is characterized by having an image display portion having a hexagonal pixel structure arranged in a delta array. To do.

In order to achieve the above-mentioned object, an image input / output system for displaying an image picked up by an image pickup device on an image display device according to the second aspect of the present invention is also provided.
An image display device having an image display unit having a delta-arranged hexagonal pixel structure is formed by capturing an image with an image input device having an image pickup element having a delta-arranged rectangular or hexagonal pixel structure. It is characterized in that an image is input and displayed by this image display device. This feature is different from the conventional technique in which display is performed by a quadratic pixel structure in which delta arrangement or square arrangement is performed irrespective of the pixel structure at the time of image capturing.

Furthermore, in the image input / output system according to the third aspect of the present invention, a pseudo pixel block composed of a set of a large number of pixels is used for both or one of the image pickup and the display in the second aspect. It is characterized by realizing a delta-arranged quadrangular shape or a hexagonal pixel structure.

In the present invention, since the Nyquist limit of the delta array is adapted to the anisotropy of vision, it is noted that high image quality can be obtained, and the pixel shape is taken into consideration in imaging and displaying the delta array structure. This is a method that synergistically improves image quality by optimally combining them.

An image pickup device having a delta-arranged quadrangular pixel structure according to the present invention has a resistance to aliasing distortion due to incomplete optical filtering at the time of image pickup with respect to a spatial frequency distribution after image pickup. At the same time, the horizontal and vertical components, which have high visual contrast sensitivity with respect to the original image component, are well preserved to improve the appearance of the image.

Further, the image pickup device having the hexagonal pixel structure of the delta arrangement is subjected to the optical filtering that sharply attenuates the spatial frequency component above the Nyquist limit, that is, the ideal optical filtering. It is effective in capturing an image relatively clearly when the above procedure is performed. This is because the hexagonal pixel shape is longer in the vertical direction than the quadrangular pixel shape, so that the preservation state of the horizontal frequency component of the original image within the Nyquist limit is improved as shown in FIG. . As for the vertical frequency component in FIG. 1B, the rectangular pixel shape and the hexagonal pixel shape overlap each other. With the hexagonal pixel shape, a relatively sharp image can be obtained as it is without performing image processing because the horizontal frequency component having a high visual contrast sensitivity has a good preservation state in the high frequency region within the Nyquist limit.

On the other hand, the image display device having the image display section having the hexagonal pixel structure in the delta arrangement is effective in making the display pixel structure hard to be perceived. This is because unnecessary high frequencies caused by the pixel structure of the horizontal component having high contrast sensitivity are cut off and released to the diagonal component having low contrast sensitivity.

When the combination of the pixel structure in the image pickup and the display as described above is used, the spatial frequency distribution after the display is
For example, as shown in FIG. In FIG. 2, reference numeral 12 denotes a spatial frequency distribution of harmonics after display in the case where delta-arranged quadrangular pixels are used as the imaging pixel structure in the second invention when optical filtering is incomplete, and 12 'denotes optical filtering. Is incomplete, in the second invention, the spatial frequency distribution of the original image after display in the case of using the quadrangular pixels arranged in the delta as the imaging pixel structure, 13 is the second when the optical filtering is incomplete. Spatial frequency distribution of harmonics after display when hexagonal pixels arranged in a delta array are used as an imaging pixel structure in the present invention, 13 '
Is the spatial frequency distribution of the original image after display when hexagonal pixels arranged in delta are used as the imaging pixel structure in the second invention when the optical filtering is incomplete, 14
Shows the spatial frequency distribution of the harmonics after the display by the conventional method when the optical filtering is incomplete, and 14 'shows the spatial frequency distribution of the original image after the display by the conventional method when the optical filtering is incomplete. Further, 15 is the spatial frequency distribution of the harmonics after display when the delta-arranged quadrangular pixels are used as the imaging pixel structure in the second invention when the optical filtering is complete, and 15 'is the optical filtering complete. In this case, in the second invention, the spatial frequency distribution of the original image after display when the delta-arranged rectangular pixels are used as the imaging pixel structure in the second invention, and 16 is the imaging pixel structure in the second invention when the optical filtering is perfect. As a spatial frequency distribution of harmonics after display when using delta-arranged hexagonal-shaped pixels, 16 'is a delta-arranged hexagonal-shaped image pickup pixel structure in the second invention when optical filtering is complete. Spatial frequency distribution of the original image after display when using pixels, 17 is after display by conventional method when optical filtering is perfect Spatial frequency distribution of harmonics, 17 'denotes a spatial frequency distribution of the original image after the display according to the conventional method in the case where the optical filter is perfect. Here, in FIG. 2, when the component amount is large, it is represented by a thick line, and when it is small, it is represented by a thin line. The point where the lines intersect is the point with spatial frequency 0.

If the optical filtering is incomplete, the second
In the image input / output system according to the present invention, when the delta-arranged quadrangular pixels are used as the image pickup pixel structure, the residual amount of the high frequency component is smaller than that of the conventional method 14 as shown by 12, as in the case of 13. As for the original image component, as shown in 12 ', the horizontal and vertical components with high visual contrast sensitivity are preserved without omission, and the diagonal components are preserved. Stored in. Therefore, the SN ratio is the highest in the method that uses the delta-arranged rectangular pixels as the imaging pixel structure. In particular, the vertical component is excellent because the original image and the high frequency do not interfere with each other.

On the other hand, if the optical filtering is perfect,
In the image input / output system according to the second aspect of the present invention, when hexagonal pixels arranged in a delta array are used as the image pickup pixel structure, as shown in 16, a vertical component of high frequency is obliquely low in visual contrast sensitivity, as in 15. It escapes to the direction component. Also, as shown at 16 ', the horizontal component of the original image is best preserved. Therefore, the method using the delta-arranged hexagonal pixels as the imaging pixel structure has the highest SN ratio.

In both the image input / output system according to the second and third aspects of the present invention, under the respective optical conditions, image pickup and display are performed by combining the delta-arranged quadrangular pixel structures capable of obtaining high image quality in the conventional method. The image quality is improved as compared with the case of performing it. In particular, in the image input / output system according to the second aspect of the present invention, when the delta-arranged quadrangular pixels are used as the image-capturing pixel structure, the image quality is higher than that of the conventional combination of the image-capturing and the image, regardless of the optical filter characteristics. Excellent and versatile.

As described above, the present invention enables image display in which the image quality is hard to be perceived. Further, according to the second aspect of the present invention, these processes are performed by the hardware in which the pixel shape is processed, so that the processing time is the same as that of the conventional pixel structure, and high-speed processing is possible, and the limited image data can be displayed. Pixels can be displayed at high speed and with little perceptibility.

Further, regarding the third aspect of the invention, in the case of display, for example, as shown in FIG. 3, low-definition image data is distributed to the original pixels of the image display device in the hexagonal pseudo pixel block. The pseudo pixel block composed of a large number of pixel groups is for realizing the hexagonal pixel structure in the second invention in a pseudo manner, and when the pseudo pixel block is sufficiently larger than the pixel, the second invention is used. The same effect as in case of is obtained. As described above, the image input / output system according to the third aspect of the present invention only allocates the image data to the pixels in the pseudo pixel block, does not require a special calculation process, and has a limited amount such as when the communication capacity is small. When it is necessary to display the image data at low cost and high image quality in real time, the image data can be displayed at high speed and the pixels are hardly perceived, which is preferable.

[0031]

Embodiments of the present invention will be described below in detail with reference to the drawings.

<First Embodiment> FIG. 4 is a diagram for explaining a first embodiment of the present invention relating to an image input / output system. In FIG. 4A, 1 is an optical system in which an inexpensive optical low-pass filter such as a lens 1a and a multilayer crystal filter 1b having an incomplete cutoff characteristic is inserted, and 2 is a quadrangular shape as shown in FIG. 4B. Is an image pickup device having a pixel structure in which the image pickup pixels 2a are arranged in a delta arrangement. These are
It constitutes a part of an image input device that captures an image of the imaging target 101 and inputs an image. An image transmission system 3 includes a transmission device and a transmission line for transmitting the digitized image data to the image display device. Reference numeral 4 denotes an image display unit having a pixel structure in which hexagonal display pixels 4a are arranged in a delta arrangement as shown in FIG. 4C, and the transmitted image data is directly distributed to the pixels for display. This is a pixel display device presented at 102.

As described above, when the optical system 1 which is inexpensive in terms of cost balance is used, a relatively large amount of aliasing distortion is mixed in the original image component. In that case, as described above, the method of using the image pickup device having the delta-arranged rectangular pixel structure and the image display device having the delta-arranged hexagonal pixel structure is suitable. Yes, it is confirmed by subjective evaluation.

FIG. 5 shows the result of logical verification by modeling the anisotropy of vision and defining the SN ratio by the ratio of the original image component and the high frequency component within the perceptual limit. 18
Shows the change in the SN ratio with respect to the viewing distance when image pickup and display are performed by a square-shaped rectangular pixel structure that is generally used when optical filtering is incomplete. Reference numeral 19 denotes S for the visual distance when hexagonal pixels arranged in a delta array are used as the imaging pixel structure and the display pixel structure when the optical filtering is incomplete.
The change of N ratio is shown. Reference numeral 20 denotes a case where the delta-arranged quadrangular pixels are used as the imaging pixel structure and the delta-arranged hexagonal pixels are used as the display pixel structure when the optical filtering is incomplete, that is, the case of the present embodiment example. 3 shows a change in the SN ratio with respect to the viewing distance. Reference numeral 21 indicates the S for the viewing distance by the method that best combines conventional imaging and display when optical filtering is incomplete.
The change of N ratio is shown. As is apparent from FIG. 5, when the optical filtering is incomplete, the combination of the pixel structures in the image pickup and display of the present embodiment shown by 20 is excellent. As described above, the present invention has an advantage that a high image quality can be obtained even with the same viewing distance, and the image can be brought closer to the screen even with the same image quality.

<Second Embodiment> FIG. 6 is a view for explaining a second embodiment of the present invention related to an image input / output system. In FIG. 6A, reference numeral 5 denotes an optical system in which an expensive optical low-pass filter such as a lens 5a and a phase filter 5b for obtaining ideal characteristics is inserted, and 6 denotes a hexagonal shape as shown in FIG. 6B. This is an image sensor having a pixel structure in which the image pixels 6a are arranged in a delta arrangement. These are the imaging target 10
3 constitutes a part of an image input device for capturing an image and inputting an image. Reference numeral 3 is a transmission device and a transmission path for transmitting the digitized image data to the image display device. 4 is shown in FIG.
As shown in (c), it has an image display section having a pixel structure in which hexagonal display pixels 4a are arranged in a delta arrangement, and the sent image data is directly distributed to the pixels and displayed, and presented to the observer 102. It is a pixel display device.

As described above, when the optical system 5 using an expensive optical filter capable of obtaining a nearly ideal cutoff characteristic is used, aliasing distortion is hardly mixed in the original image component. In that case, the method of using the image pickup device 6 having the delta-arranged hexagonal pixel structure and using the image pickup display device 4 having the delta-arranged hexagonal pixel structure is suitable. As it was, the first
The result of theoretical verification similar to that of the embodiment is also obtained.

FIG. 7 shows a theoretical verification result. Reference numeral 18 'shows a change in the SN ratio with respect to the viewing distance when image pickup and display are performed by a square-shaped square pixel structure that is generally used when optical filtering is complete. Reference numeral 19 ′ shows a change in the SN ratio with respect to the viewing distance in the case where the delta-arranged hexagonal pixels are used as the imaging pixel structure and the display pixel structure when the optical filtering is complete, that is, in the case of this embodiment. . Reference numeral 20 ′ shows a change in the SN ratio with respect to the viewing distance in the case where the delta-arranged rectangular pixels are used as the imaging pixel structure and the delta-arranged hexagonal pixels are used as the display pixel structure when the optical filtering is complete. Show. Reference numeral 21 'shows the change in the SN ratio with respect to the viewing distance according to the method in which the conventional imaging and display are best combined when the optical filtering is perfect. As is clear from FIG. 7, in the case where the optical filtering is perfect, the combination of the pixel structures in the image pickup and display of the present embodiment example shown by 19 ′ is excellent. As described above, the present invention has an advantage that a high image quality can be obtained even with the same viewing distance, and the image can be brought closer to the screen even with the same image quality. In addition, 2
As shown by 0 ', when the delta-arranged quadrangular pixels are used as the imaging pixel structure and the delta-arranged hexagonal pixels are used as the display pixel structure, it is excellent even when the optical filtering is perfect. It can be seen that excellent image quality is obtained and it is versatile.

<Third Embodiment> FIG. 8 is a diagram for explaining a third embodiment of the present invention relating to an image input / output system. Reference numeral 1 is an optical system in which an inexpensive optical low-pass filter such as a lens 1a and a multilayer crystal filter 1b having an incomplete cut-off characteristic is inserted, and 10 is a delta array of quadrangular imaging pixels 10a as shown in FIG. 9A. It is a low-definition image pickup device having the above-described pixel structure and lower than the pixel structure of the image display device. These constitute a part of one image input device which images the image pickup target 101 and inputs an image. Reference numeral 5 denotes an optical system in which an expensive optical low-pass filter such as a lens 5a and a phase filter 5b for obtaining ideal characteristics is inserted, and 11 denotes a hexagonal imaging pixel 1 as shown in FIG. 9B.
1a has a pixel structure in which it is arranged in a delta arrangement, which is a low-definition image sensor as compared with the pixel structure of an image display device. The optical system 5 and the image pickup device 11 constitute a part of another image input device that picks up an image of the image pickup target 103 and inputs an image. Reference numeral 3 denotes a transmission device and a transmission line for transmitting the digitized image data to the image display device. In the illustrated example, two sets are provided corresponding to the two image input devices. Reference numeral 7 is a display image processing apparatus that enables display in an arbitrary pixel shape in a pseudo manner by distributing the transmitted image data to the original pixels of the image display apparatus in a pseudo pixel block, which is a set of pixels. The image display device has a high-definition image display unit having a relatively high pixel density and presents a display image to the observer 102. However, the image display device 8 is not limited in type, such as a CRT, a liquid crystal display, and a plasma display, as long as it has a relatively high definition.

In the pixel display device 8 of the present embodiment example, as shown in FIG.
As shown in (d), the original pixels are gathered together to realize a hexagonal pixel in a pseudo manner, and the display pseudo pixel block 8a thus realized is arranged in a delta as shown in FIG. 9C. And Therefore, as shown in FIG. 10, the display image processing apparatus distributes the pixels of the image data sent from the image transmission system 3 to the original pixels of the pixel display apparatus 8 in the hexagonal display pseudo pixel block 8a. Perform processing to

When the display pixel structure is constructed in a pseudo manner as described above, there is an advantage that it is possible to display low-definition image data with high image quality, as with the advantage of the second embodiment. can get.

In addition, when transmitting low-definition image data to an image display device, it is possible to display a high quality image with a small amount of image data, and it is possible to perform real-time image communication at a low cost with a high image quality. Is obtained. For example, an inexpensive low-definition image pickup camera may be installed outdoors and the indoor monitor with high definition may be used.

Further, since the pixel structure in the display is realized by software, there is an advantage that the pixel structure can be controlled according to the contents of the image such as a natural image and CG by controlling the display image processing device 7 in real time. Have.

Although the example of FIG. 8 shows an example in which an image is input from a two-system image input device to a display system including the display image processing device 7 and the image display device 8, the display system is an input device. The input image can be displayed by switching the images or combining the images. The number and configuration of image input devices are not limited to the above. For example, images taken by various image pickup systems can be transmitted by an image transmission system, and the display system can switch and display each image, or can divide a window and display a plurality of images at the same time.

<Fourth Embodiment> FIG. 11 is a diagram for explaining a fourth embodiment of the present invention relating to an image input / output system. In FIG. 11A, 1 is an optical system in which an inexpensive optical low-pass filter such as a lens 1a and a multilayer crystal filter 1b having an incomplete cut-off characteristic is inserted, and 2 is a delta-arranged rectangular pixel structure. It is an image pickup device that has. These constitute a part of one image input device which images the image pickup target 101 and inputs an image. Reference numeral 5 is an optical system in which an expensive optical low-pass filter such as a lens 5a and a phase filter 5b capable of obtaining an ideal cutoff characteristic is inserted, and 6 is an image pickup device having a hexagonal pixel structure in a delta arrangement. The optical system 5 and the image pickup device 6 constitute a part of one image input device that picks up an image of the image pickup target 103 and inputs an image. 9 indicates, for example, to average the outputs of the original pixels of the image sensor 2 (or 6) in the imaging pseudo pixel block, which is a set of imaging pixels, and 1
It is a picked-up image processing device that outputs as individual pixel data, and two are provided corresponding to each image input device. 3
Is a transmission device and a transmission line for transmitting the digitized image data to the image display device, and two systems are provided corresponding to the two captured image processing devices 9. Reference numeral 7 denotes a display image processing apparatus which enables display in an arbitrary pixel shape in a pseudo manner by distributing transmitted image data to original pixels of the image display apparatus in the display pseudo pixel block, and 8 denotes a relatively high pixel. The image display device has a high-definition image display unit having a density to display an image and present it to the observer. However, if the image display device 8 has a relatively high definition, it is CR.
The type of T, liquid crystal display, plasma display, etc. is not limited.

In the pixel display device 8 of this embodiment, the pixel display device shown in FIG.
As shown in FIG. 1 (c), original pixels are gathered together to realize a hexagonal pixel in a pseudo manner, and the display pseudo pixel block 8a thus realized is arranged in a delta as shown in FIG. 11 (b). The configuration. In addition, in the captured image processing device 9, FIG.
As shown in FIG. 2, the original pixels of the image pickup device 2 (or 6) are gathered together to form a hexagonal image pickup pixel in a delta arrangement in a pseudo manner, and the original pixel data of the image pickup device is formed in this way. Imaging pseudo pixel block 2a (or 6a)
Is converted into image data having pixels as pixels. At that time, in this embodiment, a plurality of image pickup pixels in the image pickup pseudo pixel block 2a (or 6a) are averaged and converted into one pixel. The converted image data is sent from the image transmission system 3 to the display image processing device 7, and the display image processing device 7 receives the pixels of the input image sent from the image transmission system 3 as in the third embodiment. The data is distributed to the original pixels of the pixel display device 8 in the hexagonal display pseudo pixel block 8a. In addition,
The imaging pseudo pixel block 2a (or 6a) and the display pseudo pixel block 8a are preferably configured so as to correspond to each other.

By constructing the image pickup and display pixel structure in a pseudo manner as described above, low definition image data can be displayed with high image quality as with the advantages of the second and third embodiments. The advantage that is possible is obtained.

Further, when image data is transmitted to the image display device through a line having a limited communication capacity, it is possible to display a high quality image with a small amount of image data, which enables real-time image communication with a high image quality at a low cost. The advantage is obtained. For example, it can be used as a simple compression / decompression method in the case of multiplex transmission of image data picked up by installing a large number of cameras in a video conference or the like through a low capacity communication line.

Further, since the pixel structure in image pick-up and display is realized by software, by controlling the picked-up image processing device 9 and the display image processing device 7 in real time, the same image as in the third embodiment can be obtained. There is also an advantage that the pixel structure can be controlled according to the contents of.

Note that the example of FIG. 11 also shows an example in which an image is input from the two image pickup systems to the display system, but the display system switches input images as in the third embodiment. , The input image can be displayed by combining the images. The number and configuration of image input devices are not limited to the above. For example, images taken by various image pickup systems can be transmitted by an image transmission system, and the display system can switch and display each image, or can divide a window and display a plurality of images at the same time.

<Fifth Embodiment> FIG. 13 is a view for explaining a fifth embodiment of the present invention related to an image input / output system. In FIG. 13A, reference numeral 1 is an optical system in which an inexpensive optical low-pass filter such as a lens 1a and a multilayer crystal filter 1b having an incomplete cutoff characteristic is inserted, and 2 is a delta-arranged rectangular pixel structure. It is an image pickup device that has. These constitute a part of one image input device which images the image pickup target 101 and inputs an image. 5
Is an optical system in which an expensive optical low-pass filter such as a lens 5a and a phase filter 5b having an ideal cutoff characteristic is inserted, and 6 is an image pickup device having a hexagonal pixel structure in a delta arrangement. The optical system 5 and the image pickup device 6 constitute a part of another image input device that picks up an image of the image pickup target 103 and inputs an image. 9
Is a picked-up image processing device having the same function as that of the fourth embodiment, and two are provided corresponding to each image input device. Reference numeral 3 denotes a transmission device and a transmission line for transmitting the digitized image data to the image display device, and two systems are provided corresponding to the number of image pickup systems. Reference numeral 4 denotes an image display device having an image display unit having a pixel structure in which hexagonal display pixels 4a are arranged in a delta arrangement as shown in FIG. 13B to display an input image and present it to the observer 102.

In the picked-up image processing device 9 of this embodiment,
Similar to the fourth embodiment, the original pixels of the image sensor 2 (or 6) are gathered together to form a hexagonal imaging pixel in a delta arrangement in a pseudo manner, and the original pixel data of the image sensor is Imaging pseudo pixel block 2a configured as follows
(Or 6a) is converted into image data having pixels. At that time, the plurality of image pickup pixels in the image pickup pseudo pixel block 2a (or 6a) are converted into one pixel by averaging the plurality of image pickup pixels.
The converted image data is sent from the image transmission system 3 to the image display device 4 and displayed. The imaging pseudo pixel block 2a (or 6a) is preferably configured so as to correspond to the display pixel 4a.

When the image pickup pixel structure is constructed in a pseudo manner as described above, it is possible to display low-definition image data with high image quality, like the advantages of the second and third embodiments. The advantage is obtained.

Further, when image data is transmitted to the image display device through a line having a limited communication capacity, it is possible to display with high image quality with a small amount of image data, and it is possible to perform real-time image communication with high image quality at low cost. The advantage is obtained.

In addition, for example, when a high-definition image is displayed on a low-definition image display device, such as displaying an image picked up by an HDTV camera on an NTSC monitor, high-quality real-time display is possible. .

Further, since the pixel structure in the image pickup is realized by software, by controlling the picked-up image processing apparatus in real time, the pixel structure is controlled according to the contents of the image as in the third embodiment. There are also advantages.

Although the example of FIG. 13 also shows an example in which an image is input to the image display device from two image pickup systems,
Similar to the third embodiment, the image display device can switch the input images or combine the images to display the input images. The number and configuration of image input devices are not limited to the above. For example, images taken by various image pickup systems can be transmitted by an image transmission system, and the display system can switch and display each image, or can divide a window and display a plurality of images at the same time.

[0057]

As described above, according to the image display device of the first aspect of the present invention, the delta-arranged hexagonal pixel structure is caused by the horizontal component pixel structure having high contrast sensitivity. Unnecessary high frequencies are cut off and released to the diagonal direction component with low contrast sensitivity, which has the advantage of making the display pixel structure less perceptible.

Further, according to the image input / output system of the second invention, when an image picked up by the image pickup device is displayed on the image display device, a hexagonal pixel structure arranged in delta in the display is adopted. By using and optimizing the combination with the pixel structure in imaging according to the optical system,
Even with the same viewing distance, high image quality can be obtained, and even with the same image quality, there is an advantage that the image can be brought closer to the screen. Further, when the captured image data is transmitted to the image display device through a line having a limited communication capacity, it is possible to display a high quality image with a small amount of image data, which is an advantage of enabling a high quality real-time image communication. can get.

Further, according to the image input / output system of the third aspect of the invention, in addition to the above advantages, the advantage that the pixel structure can be controlled according to the content of the image such as automatic image and CG is obtained.

[Brief description of drawings]

1A and 1B are explanatory diagrams of a storage state of an original image component within a Nyquist limit for explaining an operation of the present invention.

FIG. 2 is an explanatory diagram of a spatial frequency distribution after display for explaining the operation of the present invention.

FIG. 3 is an explanatory diagram of a pseudo pixel block according to a third aspect of the present invention.

4 (a), (b), and (c) are explanatory views of a first embodiment example of the present invention.

FIG. 5 is a diagram showing an effect obtained by theoretically verifying the effect of the present invention when an inexpensive optical system is used.

6 (a), (b) and (c) are explanatory views of a second embodiment example of the present invention.

FIG. 7 is a diagram showing an effect obtained by theoretically verifying the effect of the present invention when an ideal optical system is used.

FIG. 8 is an explanatory diagram of a third embodiment example of the present invention.

9 (a), (b), (c) and (d) are the same as those in the third embodiment.
3 is an explanatory diagram of a pixel structure in the embodiment example of FIG.

FIG. 10 is an explanatory diagram of a display image processing device according to the third embodiment.

11 (a), (b) and (c) are explanatory views of a fourth embodiment of the present invention.

FIG. 12 is an explanatory diagram of a captured image processing device according to the fourth embodiment.

13 (a) and 13 (b) are explanatory views of a fifth embodiment of the present invention.

FIG. 14 is an explanatory diagram of a delta arrangement of pixels in an image display device using integral additive color mixing.

FIG. 15 is an explanatory diagram of a Nyquist limit of a delta arrangement of pixels.

FIG. 16 is an explanatory diagram of visual spatial anisotropy.

17A is an explanatory diagram of an RGB delta array in a pixel display device using spatial average additive color mixing, and FIG. 17B is an explanatory diagram of an RGGB square array in a pixel display device using spatial average additive color mixing.

FIG. 18 is an explanatory diagram of a delta array in the image sensor.

19 (a), (b), and (c) are for improving image quality.
It is explanatory drawing of the typical example of the image input / output system performed conventionally.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical system including an optical filter having imperfect characteristics 2 ... Image pickup device having a delta-arranged rectangular image pickup pixel structure 3 ... Digital transmission device and transmission line 4 ... Delta-arranged hexagonal display pixels Image display device having structure 5 ... Optical system including optical filter having ideal characteristics 6 ... Image sensor having hexagonal imaging pixel structure in delta array 7 ... Display image processing device 8 ... High-definition image display device 9 ... Captured image processing device 10 ... Having a delta-arranged rectangular pixel structure,
Image pickup device having a lower definition than that of an image display device 11 ... Having a hexagonal pixel structure in a delta arrangement,
Image sensor with lower definition than image display device

Claims (3)

[Claims] 1. An image display device comprising an image display unit having a hexagonal pixel structure in a delta arrangement. 2. An image input / output system for displaying an image picked up by an image pickup device on an image display device, the image input having an image pickup device having a delta-arranged quadrangular or hexagonal pixel structure. And an image display device having an image display unit having a hexagonal pixel structure arranged in a delta array, wherein an image is input by the image input device and an image is displayed by the image display device. Image input / output system characterized by. 3. A delta-arranged quadrangular or hexagonal pixel structure is realized by using a pseudo pixel block composed of a large number of pixels in both or one of an image sensor and an image display unit. The image input / output system according to claim 2, further comprising: