JPH05281936A - Binary image display device - Google Patents

Abstract

PURPOSE:To provide the binary image display device which can make a binary artificially multi-gradational display of a color still picture or color moving picture and reduces the movement of a view point and the cost of a system by clearly displaying an image, generated by making the artificially multi- gradational display of a color image, on one display unit together with the binary image. CONSTITUTION:A terminal 1 of a TV conference system is connected to a line through a network interface part 3. When color still picture information is received from an opposite terminal, encoded data from a multi-media multiplexing and demultiplexing part 4 are stored in the buffer of a still picture encoding and decoding part 6, only brightness information is extracted by a system control part 2 from the encoded data, and the decoded data are stored in another buffer. The data are processed by dither conversion into artificially multi-gradational display data and the color image is displayed on an LCD, which is arranged in the conference system and makes a binary image display, with multi-gradations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binary image display device, and more particularly to converting color image information of a still image or a moving image into binary pseudo multi-gradation display data for display, for example, a TV conference device or a videophone. Device or AGC (Audio Graphic Cofe)
The present invention relates to a binary image display device used for a terminal device or the like.

[0002]

2. Description of the Related Art A conventional binary image display device is used as a terminal device for displaying still image information by soft copy, such as "Pen Telephone" by Shimadzu Corporation and P.I. Although there are AGC terminal devices described in 13 and the like, none of them could display a color image.

[0003]

As described above, the conventional two
AGC terminal device or TV equipped with a value image display device
The still image transmission device of the conference system cannot display the color still image information even if it is received, and the received color image information is discarded or transmitted from the other terminal by prior negotiation. Was rejected.

For this reason, it is not possible to know not only the color information but also the brightness information in the color still image information in an AGC terminal device or the like which does not have a color image display device on the receiving terminal side. However, the transmitted color image information is not limited to an image that always requires color information, and in some cases it may be sufficient if the outline is identified by luminance information. Conventionally, only a binary image display device is provided on the receiving side. If not, there was a problem that the color image could not be transmitted.

Further, in the case of a terminal focusing on the function of high-definition still image transmission such as an AGC terminal device, in order to communicate with a partner terminal having a color moving image transmission function, a binary image is required. CRT (Cathode Ray Tu
There is a problem in that the device cost increases because moving images cannot be communicated without a color moving image display device such as bu).

Further, even in a still picture transmission device connected to and built in to a TV phone or a TV conference system, a map of a communication partner or an object picture as a meeting material is displayed during a meeting using still pictures. In order to confirm a moving image that is present, the viewpoint must be moved to a moving image display device that is separately provided, and there is a problem that usability of the device is reduced.

The present invention has been made in view of the above conventional problems, and it is possible to clearly display a color still image or a color moving image on a binary image display device by pseudo multi-gradation display. An object of the present invention is to provide a binary image display device capable of reducing system cost by displaying a binary image and a color pseudo multi-gradation display image at the same time on a display, and reducing the cost of the system. And

[0008]

The invention according to claim 1 is
Connected to or built in a communication terminal device such as an AGC terminal device or a TV conference terminal device that communicates voice information and image information between a plurality of points via a communication line, and displays an image in binary.
In the value image display device, a color still image brightness information extraction means for extracting only brightness information from the color still image information sent from the partner terminal, and a minute area based on the brightness information of the extracted color still image. Pixel multi-gradation still image data conversion means for converting binary pixel density for each pixel and converting to binary multi-gradation display data by binary, and received color still image information. Is converted into the pseudo multi-gradation display data, and is displayed as a binary still image with light and shade.

According to a second aspect of the present invention, a binary value is provided which is connected to or built in a communication terminal device such as an AGC terminal device or a TV conference terminal device which communicates voice information and image information between a plurality of points via a communication line. In a binary image display device for displaying an image by means of a color moving image brightness information extracting means for extracting only brightness information from color moving image information sent from a partner terminal, and based on the extracted brightness information of the color moving image. Pseudo multi-gradation moving image data conversion means for changing the binary pixel density for each minute area and converting the binary pixel density into pseudo multi-gradation display data for multi-gradation display. It is characterized in that the information is converted into the pseudo multi-gradation display data and is displayed as a binary moving image with light and shade.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the binary image display device described above, the pseudo multi-gradation still image data conversion unit or the pseudo multi-gradation moving image data conversion unit extracts the luminance information from the received color image information and decodes the decoded information. Take out the matrix of the predetermined area from, compare the value of the dither matrix with an arbitrary threshold level for each pixel,
A binary image is generated based on the comparison result, and the threshold level of the dither matrix to be compared with the decoded data can be freely changed.

The invention according to claim 4 is the same as the invention according to claim 2.
In the value image display device, a frame designating unit that designates an arbitrary frame of color moving image information sent from the partner terminal, and a still image capturing device that captures pseudo multi-gradation display data corresponding to the designated moving image information as still image information. And image information extracting means.

[0012]

According to the invention of claim 1, when the image information received from the partner terminal is color still image information, only luminance information is extracted from the color still image information, and pseudo multi-gradation display data is extracted from the luminance information. Convert to (dither conversion). For this reason,
A binary image and a color still image can be displayed in grayscale only with a binary image display device, and the outline of color image information can be transmitted without providing a separate color image display device, and the cost of the terminal device can be reduced. You can

According to the second aspect of the invention, when the image information received from the partner terminal is color moving image information, only the luminance information is extracted from the color moving image information and the luminance information is converted into pseudo multi-gradation display data. Then, these processes are repeated for each frame. Therefore, it is possible to display the grayscale of the binary image and the color moving image only with the binary image display device.
The outline of moving images can be transmitted without separately providing a color moving image display device, the cost of the terminal device can be reduced, and the image can be displayed on one display, so that it is not necessary to move the viewpoint to confirm the moving image. Becomes

According to the third aspect of the invention, when the color image information is converted into the pseudo multi-gradation display data in the binary image display device, the threshold level of the dither matrix which determines the binary value for each pixel can be freely set. It can be changed. Therefore, the density of the pseudo multi-gradation display can be freely controlled on the receiving side, and a clear image with less crushing or blurring of the image can be obtained.

According to the fourth aspect of the present invention, since one screen of the moving image information can be taken in the memory as still image information, various editing functions can be realized by using this still image information.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a TV incorporating a binary image display device according to the present invention.
It is a block diagram which shows the structure of the terminal device of a conference system. First, the configuration will be described.

In the figure, 1 is a terminal device of a TV conference system in which the binary image display device of the present invention is incorporated, 2 is a system control unit (SCU) for controlling the entire terminal device 1, 3
Is a network interface unit (INCU) for interfacing with ISDN, and 4 is a multimedia for multiplexing / separating signals for each medium (voice, video, still image data) used in this system on the ISDN transmission line. Multiplexing / demultiplexing unit (MPX / DMPX), 5 is a voice encoding / decoding unit that performs analog / digital conversion of voice and further performs encoding / decoding, and 6 is a still image code that encodes / decodes still image data. A decoding unit, 7 is a moving picture coding / decoding unit that codes / decodes a color moving image, and 8 is an interface with a video camera connected to the terminal device 1, and an NTSC signal from the video camera is converted into a predetermined format. A video camera interface for converting to data, and 9 is an interface with the same monitor TV, A monitor TV interface for converting the data of the video into an NTSC signal, 10 is an image memory for holding the still image data to be displayed on the liquid crystal display (LCD) for the binary image, and 11 is an LCD for the binary image. LCD controller that generates various timing signals to drive the LCD by interfacing with
Is an audio interface for interfacing with a microphone or speaker connected to the terminal device 1, 13
Similarly, the touch panel interface (as shown in the figure, the touch panel (TP) is overlaid with the LCD,
14 is a scanner interface for connecting a scanner for reading a still image, 15 is a printer interface for connecting a printer for outputting a still image, and 16 is various types for the terminal device 1. An operation unit for performing an operation, 17 is a magnetic disk device (HD) for storing image information, management information and the like, and 18 is an ISDN line connected to the terminal device 1.

Next, the operation will be described. FIG. 2 is a flow chart for explaining the starting operation of the TV conference system according to the embodiment of the present invention. As shown in FIG. 2, first, it is necessary to connect a line before starting a video conference. This is LAPD (Link Access Procedure on t
he D-channel: Follow the normal call (or call) procedure performed through the D channel link access procedure. The user first operates the operation unit 16 as shown in FIG.
Enter the ISDN number of the other party's terminal, and then instruct calling. The operation of the operation unit 16 is analyzed by the system control unit 2, and the system control unit 2 controls the network interface unit 3 to make a call (SETUP) to the ISDN line 18 (step 100).

FIG. 3 is a signal sequence chart between the terminal devices in this embodiment. First, the SETUP (call setup message) defines the transfer capability (BC) as unrestricted digital, and the lower layer compatibility (LLC) as H.264. 221, High Layer Consistency (HCL) is sent out as a conference. When the partner terminal analyzes the SETUP and the communication possibility is approved, the partner terminal returns a CONN (response) (step 101),
The call is established (step 102). Here, in the lower layer consistency, the H.264 standard is used. 221 is CCITT Recommendation H.221 executed by the multimedia multiplexing / separating unit 4 in FIG.
221 has been implemented.

When the call is established, the system control unit 2 controls the multimedia multiplexing / demultiplexing unit 4 to send out a multi-frame synchronization signal to establish multi-frame synchronization as shown in FIG. Step 103). Furthermore, the system control unit 2 uses CCITT Recommendation H.264. According to 242, the multimedia multiplexing / separation unit 4 is controlled to notify the capability (step 104), and the communication mode is established (step 105). This is based on H.264. On the BAS signal on 221
Set the required channels and assign the bit rate with the common capability. In the present embodiment, three channels of voice, moving image, and data (still image) are assigned.

When the communication mode is determined in this way, each channel can be treated as independent B channel (Bch) data (step 10).
6) The necessary protocol is created for each channel, and the operation as the conference system is started (step 107).
The voice channel is connected to the voice encoding / decoding unit 5, and a hands-free call using a microphone / speaker is possible via the audio interface 12.

The moving picture channel is connected to the moving picture coding / decoding unit, the received image is input to the monitor TV through the monitor TV interface 9, and the transmitted image is input from the video camera through the video camera interface 8. To be done. Also, when the data of is determined to be a binary still image (MMR) by the protocol, the still image code /
It is connected to the decoding unit 6.

Then, the received data is decoded and temporarily stored in the image memory 10 and displayed on the LCD via the LCD controller 11. The transmission data is read from the scanner via the scanner interface 14, and the still image encoding / decoding unit 6 via the system control unit 2.
Entered in. Alternatively, when transmitting the data (encoded) accumulated in the magnetic disk device 17,
The system control unit 2 controls the magnetic disk device 17, reads data, and transfers it to the multimedia multiplexing / separating unit 4. If the received data is not a binary still image (MMR), the data is discarded by the protocol and is not displayed.

Next, when the terminal device 1 of the TV conference system of this embodiment receives the color still image information from the partner terminal, it operates as follows. FIG. 4 is a block diagram showing the configuration of the still image coding / decoding unit of the binary image display device according to the first aspect of the invention. In the figure, 19 is a buffer for storing encoded data, 20 is an MMR encoder / decoder, 21 is a variable length encoder / decoder, 22 is a quantizer / inverse quantizer, and 23 is a DCT (discrete cosine transform).・ Inverse DCT, 24
Is a buffer for storing the decoded data.

FIG. 5 is a flow chart for explaining the operation of the binary image display device according to the first aspect of the invention. Figure 5
If the data received in step 203 is MMR encoded binary still image data according to the data channel protocol of step 200 as shown in FIG.
In step 215, the system control unit 2 causes the multimedia multiplexing / demultiplexing unit 4 to the buffer 1 of the still image coding / decoding unit 6
9, the MMR encoder / decoder 20 is operated (step 216), the MMR decoding is performed (step 217), and the decoding of one image is completed (step 2).
18), the data is read into the buffer 24 (step 2
19) and a scaling process is performed (step 220).

If the still image information is not the binary still image in step 203 but the color still image information is color still image data (step 204), the data is transferred from the multimedia multiplexing / separating unit 4 to the buffer 19 ( Step 20
5), the system control unit 2 controls the still image coding / decoding unit 6 to control the variable length coding / decoding unit 21, the quantizing / dequantizing unit.
22, activate the DCT / inverse DCT device 23 (step 20)
6). The buffer 19 includes a multimedia multiplexing / separating unit 4
The encoded data from is stored, but only the luminance information is extracted from this encoded data and transferred to the variable-length code / decoder 21 for decoding processing (step 207) to decode one image. When finished (Step 2
08), the data is read into the buffer 24 (step 2
09), scaling processing is performed (step 210), and dither processing is performed in step 211.

FIG. 6 is a diagram showing the structure of the encoded data transferred from the multimedia multiplexing / separating unit.
As shown in FIG. 6, the encoded data is IMAGE /
It has three hierarchical structures of FRAME / SCAN, and the encoded data of one color still image constitutes one IMAGE sandwiched between SOI and EOI. Hierarchical encoding for encoding (input image is 1/2, 1/4, 1/8 ...
In the case of data that is reduced to 1/2 ⁿ in a pyramid and compression-encoded using the DCT (Discrete Cosine Transform) method or the Spatial method in each layer of the pyramid, one IMAGE is used. Contains multiple FRAMEs, but if not hierarchically coded, only one FRAME per IMAGE
Is included. Then, at the beginning of FRAME, a HEADER that stores parameters such as the number of lines, the number of pixels of one line, and the quantization table number is attached, and then SCA
N is connected. This SCAN1, SCAN2, SCAN
3 is Y (luminance) component, Cr (color difference) component, Cb
It corresponds to the (color difference) component. Further, at the beginning of the SCAN is a HEADER in which parameters such as a variable length coding table number are stored, followed by data.

Returning to FIG. 1 and FIG. 4 again, the system control unit 2 analyzes the above-mentioned encoded data stored in the buffer 19 and extracts the data stored in the SCAN 1, so-called luminance information. And transfers it to the variable length encoder / decoder 21. The variable-length encoder / decoder 21 performs decoding based on the transferred encoded data, and at this time, the decoding is performed according to the variable-length encoding table indicated by HEADER of SCAN.

The decoded data is further transferred to the quantizer / inverse quantizer 22, and the quantizer / inverse quantizer 22 performs inverse quantization. At this time, the quantum indicated by HEADER of FRAME. Inverse quantum is performed according to the conversion table. The inversely quantized data is further transferred to the DCT / inverse DCT unit 23, the DCT / inverse DCT unit 23 performs inverse DCT, and the decoded data is written in the buffer 24.

When the above-mentioned hierarchical encoding is used for encoding, since the differential signal has been encoded in the subsequent FRAME, decoding is performed by the same procedure and stored in the buffer 24. At this time, the decoded data of the previous FRAME is offset and added, and stored in the buffer 24. In this way, when the decoding of 1 IMAGE data is finally completed (step 208), the system control unit 2 reads the data stored in the buffer 24 (step 209), performs conversion, and then converts the converted data. The image data is transferred to the image memory 10 (step 212). At this time, the transfer address to the image memory 10 (corresponding to the display position on the LCD) is designated by the user in advance (LCD /
It is assumed that the display range is pointed on the touch panel of TP), and the address is set so that the image is displayed at the specified position based on the number of lines obtained from the HEADER of FRAME and the number of pixels of one line. Transfer while converting. Number of lines in the display range specified by the user, 1
If the number of pixels in the line is different from that obtained from FRAME, the scaling processing is performed on the data in the buffer 24 before performing the dither processing (step 210). With the above operation, the received color image can be displayed on the LCD in pseudo multi-gradation (dither) (step 21).
3).

FIG. 7 is a diagram showing an image display example on the LCD of the binary image display device according to the first aspect of the invention. Figure 7
As shown in FIG. 5, the binary image display device of this embodiment can display a binary image (MMR) and a dither image obtained by dither-converting a color still image using one binary image display area. Is. Therefore, even if a color image display device is not separately provided, if it is sufficient to know the outline of the image, it is possible to sufficiently convey the image by displaying the grayscale of black and white, and the terminal device Cost can be reduced. Moreover, since two types of images can be displayed on one display, a plurality of pieces of information can be grasped by slightly moving the viewpoint.

Next, FIG. 8 shows a second embodiment of the invention.
It is a block diagram which shows the structure of the moving image encoding / decoding part of a value image display device. In the figure, 25 is a buffer for storing encoded data, and 26 is a CITT recommendation H.264. H.261 performing encoding according to H.261. 261 encoder, 27 is also a H.264 encoder. 261 Decoder, 28 is a buffer for storing decoded data.

FIG. 9 is a flow chart for explaining the operation of the binary image display device according to the second aspect of the invention. Figure 9
As shown in, when the video channel protocol is started in step 300 and the terminal device 1 receives the color moving image information, the data is transferred from the multimedia multiplexing / separating unit 4 to the buffer 25 of the moving image encoding / decoding unit 7. Is transferred (step 303). The system control unit 2 controls the moving picture coding / decoding unit 7 to control the H.264 / AVC system. 261 The decoder 27 is activated (step 304) and the encoded data stored in the buffer 25 is transferred.

FIG. 10 is a diagram showing the structure of encoded data transferred from the multimedia multiplexing / separating unit. As shown in the figure, the encoded data is FRAME, GOB.
(Group Of Block), MB (Macro Block), BLOCK
, And one frame of a moving image is stored in one FRAME. At the beginning of FRAME, there is a HEADER that stores a frame number, format instruction information (CIF / QCIF distinction), and then G
OB is connected. At the beginning of the GOB, the GOB number,
Quantization characteristics (H.261 CODER, quantization step size in inverse quantization performed in DECODER)
The stored HEADER, etc. is attached, and then the MB is connected. At the beginning of the MB, the MB address, MB type, and motion vector information (H.261 CODER, DECO
Data is stored in BLOCK, which is followed by a stored HEADER such as information for motion compensation performed in DER), a significant block pattern (indicating a block having data in MB), and the like.

Therefore, as shown in FIG.
When the encoded data is transferred from H.25, 261 The decoder 27 is an H.264 decoder. 261 Decoding is performed according to the recommendation (step 305) and the decoded data is stored in the buffer 28. 1
When the decoding of the FRAME data is completed (step 3
06), the system controller 2 reads out the data stored in the buffer 28 and transfers it to the monitor TV interface 9 (step 307), and at the same time, dithers the read data (step 310), and also to the image memory 10. Transfer (step 311). At this time, it is assumed that the transfer address to the image memory 10 is designated by the user in advance, and based on the number of lines of the format designated by the format designation information obtained from the HEADER of the FRAME and the number of pixels of one line. , Transfers while changing the address so that the image is displayed at the specified position. Number of lines in the display range specified by the user, 1
If the number of pixels in the line is different from that obtained from FRAME, the scaling processing is performed on the data in the buffer 28 before performing the dither processing (step 309). By repeating the above operation, the received color moving image is
Pseudo multi-gradation (dither) display can be performed on the CD (step 312).

The display image on the LCD is almost the same as that shown in FIG. 7, but the dither image is displayed as a moving image. Therefore, as in the case of a still image, it is possible to grasp the outline of color moving image information without separately providing a color image display device, reduce the cost of the terminal device, and perform image display with less viewpoint movement. be able to.

FIG. 12 is a flow chart for explaining the operation of the binary image display device according to the third aspect of the invention. In the operations of the embodiments according to the above-mentioned claims 1 and 2, the dither conversion is performed when the decoded data is transferred to the image memory 10, but this conversion processing is performed by the system controller. It is done in 2. FIG. 11 is a diagram illustrating a dither conversion operation for converting color image information into pseudo multi-gradation display data. As shown in FIGS. 11 and 12, first, a matrix of 4 pixels × 4 pixels is extracted from the decoded data (step 400). This decoded data is 16-23 with black level 16 and white level 235.
Takes a value of 5. The decoded data and the dither matrix are compared for each pixel, and the pixel having a larger value on the matrix than the decoded data is set to black (data = 1) and 2
A value image is generated (step 402).
The value of the dither matrix to be compared with the decoded data is calculated on the basic dither matrix (which has threshold levels obtained by evenly dividing the levels of 16 to 235 into 16).
A matrix having threshold levels like the graph shown in FIG. 11 is calculated (step 4).
01). The value of the variable α can be specified by a user's touch panel operation or the like before or during display.

As described above, in the above-mentioned embodiment according to the invention described in claim 3, there is provided means for dynamically controlling the threshold level on the receiving terminal side. Therefore, even if the illuminance (contrast of the image) of the object on the transmitting terminal side is not appropriate, it is possible to correct the crushing or blurring of the image by adjusting the threshold level on the receiving terminal side. , A clear image can be displayed.

FIGS. 13 (a) to 13 (f) are diagrams showing an operation procedure example of the binary image display device according to the invention of claim 4, and FIG.
Is a flow chart for explaining the operation of the binary image display device according to the invention of claim 4. As shown in FIG. 13 (a), while displaying a moving image using the function according to the invention described in claim 2, the user specifies a frame by operating the touch panel (continuously in time. (One screen of the displayed moving image) (Step 500),
The system control unit 2 temporarily stores the decoded data of the corresponding frame in the working memory in the system control unit 2 (step 501). Then, the user is shown in Figure 13 (b).
As shown in FIG. 5, image accumulation (step 503) and editing can be instructed by touching an icon on the screen with a pen (step 502).

Here, the operation of synthesizing the I-frame image of the selected moving image on the already displayed still image by using the editing function and storing the synthesized image will be described below. It should be noted that normal moving image processing (display operation on the monitor TV and processing described in the operation of claim 2) is performed in parallel with the operation described below. The user can
Select editing function (composite images) as shown in (c)
(Step 504) and subsequently, as shown in FIG. 13 (d), the composite display area on the still image is pointed using the touch panel (step 506). The system control unit 2 determines the number of lines in the designated combined display area,
The number of pixels in one line is obtained, and the scaling process is performed on the decoded data stored in the working memory according to the number of pixels (step 507). Subsequently, the system control unit 2 performs the dither processing similar to the processing in the embodiment according to the invention described in claim 3 (step 508), and then the image memory 10
Data is written to the address corresponding to the above designated area (step 509). By performing the above-described processing, one frame of the moving image can be combined with the displayed still image as shown in FIG. 13 (e) (step 510).

To store the data thus synthesized, the user again operates the touch panel to instruct the storage operation, as shown in FIG. 13 (f) (step 512). The system control unit 2 transfers the data in the still image display area on the image memory 10 to the buffer 24 of the still image coding / decoding unit 6 according to the storage instruction (step 5).
13) At the same time, the MMR encoder 20 is activated (step 514). The encoded data is (step 515),
The data is transferred to the magnetic disk device 17 via the system control unit 2 (step 516) and stored.

Further, in the present embodiment, the embodiment in which the binary image display device is provided in the terminal device of the TV conference system has been shown, but in the case other than this, it is almost the same in the case of being implemented in the AGC terminal device. The operation is performed, and suitable effects can be obtained as in the above case. However, the higher layer consistency is AG
It becomes C. Further, although the system having no color still image display device has been described in the above embodiment, in the case of a system having a color still image display device as well, the luminance signal is extracted when the encoded data is transferred from the buffer 19. Instead, after decoding including the color difference signal,
This can be dealt with by extracting the luminance signal at the time of transfer from the buffer 24.

Further, as shown in FIG. 1, the above embodiment has been described as a system having a color moving image display device, but the color difference signal component is decoded in an AGC terminal having no color moving image display device. No need. In such a case, the unnecessary decoding operation (for the color difference signal) can be omitted by extracting the luminance signal during the transfer from the buffer 25 in FIG. This buffer 25
To extract the luminance signal from the MB HEA,
The significant block pattern included in DER is analyzed, the MB in which the luminance signal block exists is extracted, and the MB is further extracted.
This is possible by transferring only the luminance signal block in

[0044]

As described above, according to the first aspect of the invention, since only the luminance information is extracted from the received color still image information and the pseudo multi-gradation display is performed, for example, T
Both the binary image display and the brightness display of the color still image can be performed only by the binary image display device provided in the terminal device of the V-conference system, and the image information can be displayed without providing a separate color image display device. The outline can be transmitted, and the cost of the terminal device can be reduced.

According to the second aspect of the present invention, only the luminance information is extracted from the received color moving image information and the pseudo multi-gradation display is performed. Therefore, for example, the binary value provided in the terminal device of the TV conference system is used. It is possible to display both a binary image and a luminance of a color moving image only with the image display device.
An outline of color moving image information can be transmitted without separately providing a color image display device, and the cost of a terminal device or the like can be reduced. Further, one binary image display device can display a dither image of a binary image and a color moving image, and it is not necessary to move the viewpoint for checking both images.

According to the third aspect of the present invention, the threshold level for performing dither conversion when displaying a pseudo multi-gradation on the binary image display device can be changed by the terminal device on the receiving side. It is possible to freely control the density of gradation display, and even if the received image is crushed or blurred, it is possible to correct it and display a clear image.

According to the fourth aspect of the present invention, one screen of the moving image information can be fetched in the memory as the still image information. Therefore, the still image is superposed on the moving image by using the still image information stored in this memory. It is possible to perform various editing operations such as.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a TV conference system terminal device incorporating a binary image display device according to the present invention.

FIG. 2 is a flowchart illustrating a startup operation of the TV conference system according to the embodiment of the present invention.

FIG. 3 is a signal sequence chart between terminal devices in the present embodiment.

FIG. 4 is a block diagram showing a configuration of a still image coding / decoding unit of the binary image display device according to the first aspect of the invention.

FIG. 5 is a flowchart explaining the operation of the binary image display device according to the first aspect of the invention.

FIG. 6 is a diagram showing a structure of encoded data transferred from a multimedia multiplexing / separating unit.

FIG. 7 is a diagram showing an image display example on the LCD of the binary image display device according to the first aspect of the invention.

FIG. 8 is a block diagram showing a configuration of a moving image coding / decoding unit of a binary image display device according to a second aspect of the invention.

FIG. 9 is a flowchart explaining the operation of the binary image display device according to the second aspect of the invention.

FIG. 10 is a diagram showing a structure of encoded data transferred from a multimedia multiplexing / separating unit.

FIG. 11 is a diagram illustrating a dither conversion operation for converting color image information into pseudo multi-gradation display data.

FIG. 12 is a flowchart illustrating an operation of the binary image display device according to the invention of claim 3.

FIG. 13 is a diagram showing an example of an operation procedure of the binary image display device according to the invention of claim 4.

FIG. 14 is a flowchart illustrating an operation of the binary image display device according to the invention of claim 4.

[Explanation of symbols]

 1 terminal device 2 system control unit 3 network interface unit 4 multimedia multiplexing / demultiplexing unit 5 audio encoding / decoding unit 6 still image encoding / decoding unit 7 moving image encoding / decoding unit 10 image memory 11 LCD controller 13 touch panel interface 16 Operation unit 19 Buffer 20 MMR encoder / decoder 21 Variable length encoder / decoder 22 Quantizer / inverse quantizer 23 DCT / inverse DCT 24 Buffer 24 25 Buffer 26 H. 261 Encoder 27 H.264. 261 Decoder 28 buffer

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G09G 5/36 9177-5G // G06F 15/72 D 9192-5L H04N 7/15 8943-5C

Claims (4)

[Claims] 1. A connection or a built-in communication terminal device such as an AGC terminal device or a TV conference terminal device for communicating voice information and image information between a plurality of points via a communication line, and displaying an image in binary. In the value image display device, a color still image brightness information extracting means for extracting only brightness information from the color still image information sent from the partner terminal, and a small area based on the brightness information of the extracted color still image. Pixel multi-gradation still image data conversion means for converting binary pixel density for each pixel and converting into binary multi-gradation display data by binary, and received color still image information. Is converted into the pseudo multi-gradation display data and is displayed as a binary still image with light and shade, a binary image display device. 2. A connection or a built-in communication terminal device such as an AGC terminal device or a TV conference terminal device for communicating voice information and image information between a plurality of points via a communication line, and displaying an image in binary. In the value image display device, a color moving image brightness information extracting means for extracting only brightness information from the color moving image information sent from the partner terminal, and 2 for each minute area based on the brightness information of the extracted color moving image. Pseudo multi-gradation moving image data conversion means for changing the pixel density of the values to convert it to pseudo multi-gradation display data for multi-gradation display by two values, A binary image display device, characterized in that it is converted into tonal display data and is displayed as a binary moving image with light and shade. 3. The binary image display device according to claim 1, wherein the pseudo multi-gradation still image data conversion unit or the pseudo multi-gradation moving image data conversion unit determines brightness from received color image information. A matrix of a predetermined area is extracted from the decoded data obtained by decoding and decoding the information, and the value of the dither matrix having an arbitrary threshold level is compared for each pixel, and a binary image is obtained based on the comparison result. And a threshold level of the dither matrix to be compared with the decoded data is freely changeable. 4. The binary image display device according to claim 2, wherein a frame designation means for designating an arbitrary frame of the color moving picture information sent from the partner terminal, and a pseudo multi-frame corresponding to the designated moving picture information. A binary image display device, comprising: still image information extracting means for taking in gradation display data as still image information.