JP2007047532A - Image display system, image output device, and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decrease the amount of data of an image to be processed by varying the resolution of the image to be displayed by an image display means according to discrimination resolution determined by the view distance of a viewer who views the image. <P>SOLUTION: The image display system 1 is connected between the image output device 100 and the image display device 200 having an LCD panel 206. The image output device 100 has a distance information acquisition part 170 which acquires information on the distance between the LCD panel 206 and viewer, a resolution determination part 160 which determines first resolution based upon resolution of the image that the viewer can visually discriminate according to the distance information, and an image processing part 156 which converts the input image so that the image is displayed on the LCD panel 206 with the first resolution when the resolution of the LCD panel 206 exceeds the first resolution. The image display device 200 has an image display part 260 which makes the LCD panel 206 display the image. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image display system, an image output apparatus, and an image display apparatus that display an image to a viewer.

Conventionally, a liquid crystal panel or the like has been used as a display means of an image display device that displays an image. The resolution of such display means is determined by the number of displayable pixels constituting the display means, and the display means always displays an image with the same resolution regardless of the distance between the viewer and the display means.
In addition, when the distance between the viewer and the display unit increases, the apparatus described in Patent Document 1 below increases the distance between the viewer and the display unit in addition to enlarging the image displayed on the display unit. When the images are close to each other, the image displayed on the display means is reduced, and the image size is displayed with a constant appearance regardless of the distance between the viewer and the display means.

JP 2000-276123 A

  However, it is known that the identification resolution of the human eye decreases in inverse proportion to the viewing distance, and even if an image exceeding this identification resolution is displayed beyond the predetermined viewing distance, Therefore, identification beyond this identification resolution could not be performed. Nevertheless, since image data more than necessary is processed in order to display an image that does not consider the identification resolution, the data processing is inefficient. In addition, when the image data to be displayed is exchanged over a network or the like that is charged according to the amount of data, there is also a problem that the communication cost becomes expensive because it includes excessive and unnecessary data more than necessary. .

In order to solve the above-described problems, an image display system of the present invention includes an image output device that outputs image data, and an image display device that includes an image display unit having a first resolution and displays an input image. An image display system in which data can be exchanged between the image output device, the image output device includes an image input unit to which image data that can be separated for each pixel is input, the image display means, and the image display A distance information acquisition unit that acquires distance information with a viewer who watches the means, and resolution determination that determines a second resolution based on the resolution of an image that the viewer can visually identify based on the distance information And an image processing unit that converts the input image to be displayed at the second resolution when the first resolution exceeds the second resolution. Converted by the image processor Characterized in that it comprises an image input unit for data of the image is input, and a display driving unit for displaying the input image on the image display unit.
According to the present invention, based on the distance information between the image display means and the viewer, the second resolution is determined based on the resolution of the image that can be visually identified by the viewer, and the first display of the image display means. When the resolution exceeds the second resolution, the input image is converted to be displayed at the second resolution, so that the amount of data to be processed to display the image is reduced, and the data of this image is changed. The amount of communication and the communication cost when the image output device and the image display device are exchanged via a network can be reduced.

In order to solve the above-described problems, an image output apparatus of the present invention is an image output apparatus that outputs image data to be displayed on an image display means, and an image that can be separated is input for each pixel. An image input unit; a resolution acquisition unit that acquires the resolution of the image display unit; a distance information acquisition unit that acquires distance information between the image display unit and a viewer who views the image display unit; and based on the distance information. A resolution determining unit that determines a display resolution based on a resolution of an image that can be visually identified by the viewer; and if the resolution exceeds the display resolution, the input image is an image having the display resolution. And an image output unit that outputs the image data converted into the image of the display resolution by the image processing unit to the image display unit.
According to the present invention, based on the distance information between the image display means and the viewer, the display resolution is determined based on the resolution of the image that can be visually identified by the viewer, and the resolution of the image display means determines the display resolution. If it exceeds, the input image is converted to be displayed at the display resolution, so the amount of data to be processed to display the image is reduced, and the communication cost for transferring the image data over the network and Communication costs can be reduced.

In the present invention, the resolution determination unit determines the display resolution.
Y = 90 / X
Y: Resolution (unit: PPI [number of pixels per inch])
X: distance between the image display means and the viewer (unit: meters)
It is preferable to make a determination based on an arithmetic expression represented by:
According to the present invention, the resolution can be determined according to the identification resolution of the human eye.

In the present invention, it is preferable that the display resolution decreases stepwise as the distance between the image display means and the viewer increases.
According to the present invention, the resolution according to the distance to the viewer can be made discrete.

In the present invention, it is preferable that the resolution determination unit includes a correction unit that corrects the display resolution in accordance with the visual acuity of the viewer.
According to the present invention, the resolution can be corrected according to the visual acuity of the viewer.

  In the present invention, the image processing unit may combine and group the pixels into a rectangular shape.

In the present invention, it is preferable that the image processing unit reduces the combined rectangular pixels to approximately the same size as one pixel before the combination.
According to the present invention, the data reduction amount that can be reduced by grouping can be converted into discrete values.

  In the present invention, the distance information acquisition unit may acquire the distance information based on a signal issued by the viewer to give an operation instruction.

An image display device of the present invention is an image display device that displays an image sent from an image output device, an image input unit that receives image data sent from the image output device, and an image that displays the image A display unit, and a transmission unit that transmits the maximum resolution of the image display unit, and the image transmitted from the image output device has a maximum resolution at a distance between the image display unit and a viewer who views the image display unit. When the display resolution determined based on the display resolution is exceeded, processing is performed to display the image on the image display unit at the display resolution.
According to this invention, when the display resolution is determined based on the distance information between the image display unit and the viewer, and the maximum resolution of the image display unit exceeds the display resolution, the image displayed on the image display unit is: Since it is processed to be displayed at the display resolution, the amount of data processed by the image display device is reduced, and the amount of communication and the communication cost when inputting the image data via the network can be reduced.

  In this invention, you may further provide the image expansion part which expands the said input image according to the magnitude | size of the said image display part.

Hereinafter, an embodiment of the present invention will be described using an image display system 1 that displays various images to a viewer like a television receiver.
(Embodiment)

(Hardware configuration)
FIG. 1 is a diagram illustrating a hardware configuration of the image display system 1. In this image display system 1, an image output device 100 that outputs an image to be displayed and an image display device 200 that displays an input image are connected so as to be able to exchange image data.

  Among them, one image output device 100 includes a CPU (Central Processing Unit) 106a, a ROM (Read Only Memory) 110a, a RAM (Random Access Memory) 108a, a video decoder 114, a video processor 116, and an image. A memory 118a, a distance detection circuit 120, an input I / F (Interface) 104, and a communication I / F 122a are provided, and these hardware are connected via a bus 128a so that each signal can be exchanged.

  The CPU 106a reads various programs and data such as a basic control program stored in the ROM 110a, and develops and executes these various programs and data in a main memory area provided in the RAM 108a. Execute control.

  The video decoder 114 converts the analog image signal input to the image signal input terminal 112 a into a digital image signal that can be input to the video processor 116. Further, the video processor 116 inputs the digital image signal input from the image signal input terminal 112a or the digital image signal converted by the video decoder 114, and executes various image processing described later for each pixel unit. The image signal subjected to the image processing is output from the image signal output terminal 124 to the image display device 200. Further, the image memory 118a is a memory for temporarily storing digital image signals.

  The distance detection circuit 120 detects information related to the distance from the electrical signal output from the distance sensor 126. Although not shown, the distance sensor 126 includes, for example, a light emitting unit and a light receiving unit, and the light emitted from the light emitting unit is reflected by the object and incident on the light receiving unit. Thus, a signal corresponding to the distance from the object is output. The distance sensor 126 is not limited to a method using light, and a method using ultrasonic waves, radio waves, or the like can also be employed.

  The input I / F 104 inputs an instruction signal from the keyboard 102 or a position indicating tool (not shown). The communication I / F 122a communicates with the communication I / F 122b of the image display apparatus 200 according to a predetermined protocol.

  Next, the other image display device 200 includes a CPU 106b, a RAM 108b, a ROM 110b, an image memory 118b, an LCD controller 202, an LCD driver 204, and a communication I / F 122b. Each signal is connected so as to be exchanged by 128b. Of these hardware, the CPU 106b, RAM 108b, ROM 110b, image memory 118b, and communication I / F 122b have the same functions as the hardware of the image output apparatus 100. Abbreviated.

  The LCD controller 202 generates a drawing signal for drawing on the LCD panel 206 based on the image signal input from the image signal input terminal 112 b and stored in the image memory 118 b, and sends the drawing signal to the LCD driver 204. The LCD driver 204 sequentially draws each pixel on the LCD panel 206 by a source driver and a gate driver (not shown) in accordance with the drawing signal generated by the LCD controller 202. In the present embodiment, the image display unit 260 (FIG. 2) that displays an image employs an LCD panel 206 as a display medium. The number of pixels of the LCD panel 206 is 1920 pixels × 1080 pixels, the effective pixel size is 101.8 cm × 57.3 cm, and the panel resolution is assumed to be 48 ppi × 48 ppi (Pixels Per Inch). Yes. Information about the attributes of the LCD panel 206 is stored in the ROM 110b in advance. Further, the display medium in the present invention is not limited to the LCD panel 206, and a plasma display panel, a cathode ray tube, or the like can be employed. Further, in addition to a method for directly viewing an image displayed on a display medium, a method such as a projector for projecting and viewing an image displayed on a display medium can be employed.

(Functional configuration)
FIG. 2 is a functional block diagram showing a functional configuration of the image display system 1. Among these, one image output device 100 includes an image input unit 150a, a resolution acquisition unit 152, a communication unit 154a, an image processing unit 156, an image output unit 158, a resolution determination unit 160, and a vision input unit. 164 and a distance information acquisition unit 170. The other image display apparatus 200 includes a communication unit 154b, an attribute storage unit 254, an image input unit 150b, an image enlargement unit 250, an image drawing unit 252, and an image display unit 260. These functional units are realized by organic cooperation between the hardware resources and software described above.

  The image input unit (150a, 150b) inputs data of a digital image composed of each pixel. The image output unit 158 outputs digital image data.

  The resolution acquisition unit 152 acquires the maximum resolution of the image display unit 260 of the image display device 200 connected to the image output device 100. Specifically, since the information regarding the resolution of the image display device 200 is stored as the attribute storage unit 254 in the ROM 110b of the image display device 200, the resolution acquisition unit 152 passes through both communication units (154a, 154b). This information is acquired by communicating with the image display apparatus 200. Note that the acquired resolution information is sent to the image processing unit 156.

  The distance information acquisition unit 170 acquires information on the viewing distance between the image display unit 260 and the viewer who views the image display unit 260. Specifically, the distance between the image display unit 260 and the viewer is measured by the distance sensor 126 using a light signal emitted from the operation remote controller so that the viewer gives an operation instruction, and then the distance is detected by the distance detection circuit 120. Is converted into a signal indicating. The distance information acquisition unit 170 acquires this signal, generates information related to the distance, and sends the information to the resolution determination unit 160.

The resolution determination unit 160 determines the resolution of an image that can be identified by the viewer based on the viewing distance information sent from the distance information acquisition unit 170 based on the viewing distance information between the image display unit 260 and the viewer. . Information regarding the determined resolution is sent to the image processing unit 156. Here, the function of the resolution determination unit 160 will be described with reference to FIG. FIG. 4A shows the relationship between the display resolution and the limit distance at which this resolution can be recognized. Thus, it is known that the relationship between the viewing distance and the resolution of the human eye is inversely proportional. For example, the limit resolution Y (ppi) at the viewing distance X (m) of a person with a visual acuity of 1.0 is Can be expressed by the following equation.
Y = 90 / X

  FIG. 4B shows a display resolution sufficient for display on the image display unit 260 based on the change in the limit resolution calculated according to the distance between the viewer and the image display unit 260 and the calculated limit resolution. It is a graph. The resolution determining unit 160 determines the resolution according to the distance to the viewer by holding such a graph as a data table inside or by calculating from a mathematical formula each time.

  Further, the resolution determination unit 160 includes a visual acuity correction unit 162. That is, the visual acuity correction means 162 receives the viewer's own visual acuity from the visual acuity input unit 164 and, as shown in FIG. Correct. As a result, these resolutions according to the distance from the viewer are determined in consideration of the visual acuity of the viewer.

  The image processing unit 156 first compares the resolution of the image display unit 260 sent from the resolution acquisition unit 152 with the display resolution sent from the resolution determination unit 160. As a result, when the resolution of the image display unit 260 is larger than the display resolution, the image processing unit 156 reduces the image by a predetermined magnification in order to reduce the resolution of the image input to the image input unit 150a. The reduced image is output from the image output unit 158 to the image display device 200. Here, the ratio of two compared resolutions is adopted as the predetermined magnification. For example, when the resolution of the image display unit 260 is 200 ppi and the display resolution corresponding to the distance is 100 ppi, the image is reduced to ½. On the other hand, when the resolution of the image display unit 260 is substantially equal to or smaller than the display resolution, the image processing unit 156 performs image display from the image output unit 158 without performing special processing on the input image. Output to the device 200.

  The image enlarging unit 250 enlarges the size of the image input to the image input unit 150b to the same level as the number of panel pixels according to the information regarding the panel pixel number of the image display unit 260 stored in the attribute storage unit 254. The enlarged image is sent to the image drawing unit 252. In the present embodiment, the image enlargement unit 250 is provided independently on the image display device 200 side, but the function of the image enlargement unit 250 may be included in the image processing unit 156 of the image output device 100.

  The image drawing unit 252 displays the image sent from the image enlargement unit 250 on the image display unit 260. Specifically, an image is drawn on the LCD panel 206 by the LCD controller 202 and the LCD driver 204 in accordance with the input image signal.

(Processing flow)
FIG. 3 is a flowchart showing the process flow of the image display system 1, and the process flow of the image display system 1 will be described with reference to this figure. In order to facilitate the understanding of this process, a description will be given with reference to FIGS.

  When processing by the image display system 1 is started, first, the distance information acquisition unit 170 measures the viewing distance between the viewer and the image display unit 260 (step S10).

  Next, the resolution determination unit 160 determines the resolution of the image that can be recognized by the viewer according to the measured viewing distance (step S12). Here, for example, in the step (step S10), when the viewing distance between the viewer and the image display unit 260 is 3.6 m, the limit resolution is 25 ppi according to the above formula. The display resolution is also 25 ppi.

  Subsequently, the input image is reduced by the image processing unit 156 according to the viewing distance described above, and sent to the image display device 200 (step S14). Here, for example, it is assumed that a part of the image input to the image input unit 150a of the image output apparatus 100 has a pattern as shown in FIG. Since the resolution of the LCD panel 206 of the image display device 200 acquired by the resolution acquisition unit 152 is 48 ppi both vertically and horizontally and is larger than the limit resolution, the input image is approximately halved as shown in FIG. Reduced. At this time, each pixel of the reduced image is grouped in units of four pixels as shown in FIG. 6E according to each display pixel of the LCD panel 206. For example, when the threshold value of the white pixel and the black pixel is 2 pixels out of 4 pixels and the number of black pixels is 2 pixels or more, the grouped pixels are determined as black pixels. By grouping the entire pixels of the image in this way, the total number of pixels of the image is reduced to approximately ¼. FIG. 5 is a graph showing the relationship between the number of pixels grouped according to the viewing distance and the reduction in the total number of data. As this graph shows, the number of pixels to be grouped increases stepwise according to the viewing distance. Further, in synchronism with this, the total number of pixels of the image, that is, the number of data of the image to be processed, decreases stepwise according to the viewing distance.

  Returning to FIG. 3, the reduced image is enlarged by the image enlargement unit 250 of the image display device 200 so as to be the same as the number of pixels of the LCD panel 206 as shown in FIG. Step S16).

  Finally, the image enlarged by the image drawing unit 252 is displayed on the LCD panel 206 of the image display unit 260 (step S18), and all the processes are completed.

According to the embodiment described above, the following effects can be obtained.
(1) Since the image data sent from the image output apparatus 100 to the image display apparatus 200 decreases, the power required to transmit the data can also be reduced.

As mentioned above, although this invention was demonstrated based on embodiment shown in figure, this invention is not limited to this embodiment, The modification as described below can also be assumed.
(1) According to the viewing distance, as the resolution of the image to be displayed is reduced, the number of gradations, the frame rate, and the luminance value of the image may be simultaneously reduced. Further, the image drawing processing method on the LCD panel 206 may be changed, such as omitting the interlace / progressive (IP) conversion processing.

The figure which shows the hardware constitutions of the image display system which concerns on embodiment of this invention. The functional block diagram which shows the function structure of the image display system which concerns on embodiment of this invention. The flowchart which shows the flow of a process of the image display system which concerns on embodiment of this invention. (A) shows the relationship between the display resolution and the recognizable limit distance, (b) is based on the change in the limit resolution calculated according to the distance between the viewer and the image display unit, and the calculated limit resolution, The figure which shows the display resolution displayed on an image display part. The figure which showed the relationship between the pixel count grouped according to viewing distance, and the reduction | decrease in the total data count. (C) shows an image input to the image input unit, (d) shows a reduced image, (e) shows an image grouped in units of four pixels, (f) shows The figure which shows the image expanded so that it might become the same number of pixels of an LCD panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image display system, 100 ... Image output device, 102 ... Keyboard, 104 ... Input I / F, 106a, 106b ... CPU, 108a, 108b ... RAM, 110a, 110b ... ROM, 112a, 112b ... Image signal input terminal, 114: Video decoder 116: Video processor 118a, 118b Image memory 120 Distance detection circuit 122a 122b Communication I / F 124 Image signal output terminal 126 Distance sensor 128a 128b Bus 150a, 150b ... image input unit, 152 ... resolution acquisition unit, 154a, 154b ... communication unit, 156 ... image processing unit, 158 ... image output unit, 160 ... resolution determination unit, 162 ... visual acuity correction means, 164 ... visual acuity input unit , 170 ... Distance information acquisition unit, 200 ... Image display device, 202 ... LCD controller Over La, 204 ... LCD driver, 206 ... LCD panel, 250 ... image enlargement unit, 252 ... image drawing unit, 254 ... attribute storage unit, 260 ... image display unit.

Claims (10)

An image display system having an image output device that outputs image data and an image display unit having a first resolution, and that is connected to be able to exchange data between the image display device that displays an input image. ,
The image output device
An image input unit for inputting image data separable for each pixel;
A distance information acquisition unit that acquires distance information between the image display unit and a viewer who views the image display unit;
A resolution determining unit that determines a second resolution based on a resolution of an image that the viewer can visually identify based on the distance information;
An image processing unit that converts the input image to be displayed at the second resolution when the first resolution exceeds the second resolution;
The image display device
An image input unit for inputting image data converted by the image processing unit;
An image display system comprising: a display driving unit that displays the input image on the image display means. An image output device for outputting image data to be displayed on an image display means,
An image input unit for inputting a separable image for each pixel;
A resolution acquisition unit for acquiring the resolution of the image display means;
A distance information acquisition unit that acquires distance information between the image display unit and a viewer who views the image display unit;
A resolution determining unit that determines a display resolution based on a resolution of an image that the viewer can visually identify based on the distance information;
An image processing unit that converts the input image to be displayed as an image of the display resolution when the resolution exceeds the display resolution;
An image output apparatus comprising: an image output unit that outputs image data converted into an image having the display resolution by the image processing unit to the image display unit. The image output apparatus according to claim 2,
When determining the display resolution, the resolution determination unit,
Y = 90 / X
Y: Resolution (unit: PPI [number of pixels per inch])
X: distance between the image display means and the viewer (unit: meters)
An image output apparatus characterized by being determined based on an arithmetic expression represented by: The image output apparatus according to any one of claims 2 to 3,
The display resolution is
An image output device characterized by decreasing in a stepped manner as the distance between the image display means and the viewer increases. The image output apparatus according to any one of claims 2 to 4,
The resolution determination unit
An image output apparatus comprising correction means for correcting the display resolution in accordance with the visual acuity of the viewer. The image output apparatus according to any one of claims 2 to 5,
The image processing unit
An image output apparatus characterized in that the pixels are combined into a rectangular shape and grouped. The image output apparatus according to any one of claims 2 to 6,
The image processing unit
An image output apparatus characterized in that the combined rectangular pixels are reduced to substantially the same size as one pixel before the combination. The image output apparatus according to any one of claims 2 to 7,
The distance information acquisition unit
The image output device characterized in that the distance information is acquired based on a signal issued by the viewer to give an operation instruction. An image display device for displaying an image sent from an image output device,
An image input unit for inputting image data sent from the image output device;
An image display unit for displaying the image;
A transmission unit for sending the maximum resolution of the image display unit,
The image sent from the image output device is
When the maximum resolution exceeds the display resolution determined based on the distance between the image display unit and the viewer viewing the image display unit,
An image display device processed to be displayed on the image display unit at the display resolution. The image display device according to claim 9,
An image display device further comprising an image enlargement unit that enlarges the input image in accordance with a size of the image display unit.