JPH0244982A - System for improving resolution of radio telephone set - Google Patents

Abstract

PURPOSE:To improve apparent resolution and compatibility of an existing video telephone set by devising the system such that plural still pictures are displayed sequentially repetitively for each prescribed time at a reception side. CONSTITUTION:A video signal picked up by a video camera CAM 1 is converted into a digital video data by an analog digital converter ADC 2 and sent to a bus 3. Then the video data representing the plural still pictures are sent sequentially and each received video data is stored in a picture memories 91-9n individually and the content is read sequentially at a prescribed period for each video data and each readout video data is displayed for each prescribed time and the processing above is repeated. Thus, the apparent resolution is improved and the compatibility with the existing television telephone set is ensured.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for improving the resolution of a videophone that transmits and receives still images via a telephone line. [Prior Art] A television using a telephone line In the case of telephones (hereinafter referred to as videophones), the transmission frequency band of telephone lines is narrow and the amount of information transmitted per unit time is small. The resolution of still images based on video data is low, and in order to improve this, it has been considered to employ image compression means, improve the modulation method of carrier waves using video data, etc.

[Problem to be solved by the invention]

However, if image compression methods are adopted, modulation methods are changed, etc., compatibility with existing videophones is lost, resulting in the disadvantage that it is impossible to transmit and receive data with conventional videophones. .

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention is configured by the following means.

That is, video data representing a plurality of still images is sequentially transmitted, each piece of received video data is stored individually in an image memory, the contents of this are sequentially read out at a predetermined period for each video data, and each read video data is Each video data is displayed for a certain period of time, and these reading and display operations are repeated.

[Effect]

Therefore, on the receiving side, multiple still images are displayed sequentially and repeatedly for a certain period of time, improving the apparent resolution. Because it only needs to receive video data, compatibility with existing video phones is maintained.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to block diagrams showing embodiments.

The figure shows only the video system of the video telephone; a video signal captured by a video camera (hereinafter referred to as CAM) 1 is converted into υdigital signal video data by an analog-to-digital converter (hereinafter referred to as ADC) 2. , and is sent to bus 3.

Here, when the high-resolution keys in the keypad (hereinafter referred to as KP) 4 are operated, this information is transferred to the register (hereinafter referred to as RE).
G) 5) and is given to the microcomputer (hereinafter referred to as μCP) 6 via the bus 3, so μC
P6 responds to the switching timing generation circuit (hereinafter referred to as 5TG).
) 7, the 5TG7 drives the selector (hereinafter referred to as 5EL) 8 in synchronization with the imaging operation by the CAMl, and repeatedly starts sequential selection of image memories (hereinafter referred to as VM) 91 to 9n. .

In addition, μCP6 operates ADC2 in synchronization with the operation of 5EL8.
In order to transfer the video data from 5EL8 to 5EL8, the video data for each successive frame is sequentially and individually stored in 91 to 9n.

On the other hand, the display control circuit (hereinafter referred to as DCT) 10 has 5EL8
The contents of the VMs 91 to 9n are sequentially read out via the VMs 91 to 9n, and sent to the display monitor (hereinafter referred to as DPM) 11. As a result, video data indicating a plurality of still images stored in each of the VMs 9+ to 9n is read out sequentially. Based on this, a plurality of still images are repeatedly displayed by the DPMll, each for a certain period of time.

At this time, pVM9. If the period for selecting ~9n is T, and this is several 10 msec, which is the scanning period of a normal television, then n consecutive frames of still images will be displayed in the same way as a normal television, and these Since each frame is the same image that is slightly shifted, even in a still image of one frame, changes in the outline and brightness of the image appear to be smooth υ, and the apparent resolution is improved. do.

Next, when the transmit key in KPJ is operated, this information is held by REG 5 and given to μCP6, so μCP6 creates a signal indicating the number of still image frames n1 and the selection period T, and sends it to the compression circuit (hereinafter referred to as , CMP) 12, a digital-to-analog converter (hereinafter referred to as DAC) 13, a modulation circuit (hereinafter referred to as MOD) 14, and a direct current separation circuit (hereinafter referred to as DSP) 15, and then transmits it to the telephone line 16, and then 5EL8 The contents of the VMs 91 to 9n are sequentially transferred to the CMP 12 in synchronization with the operation of the VMs 91 to 9n.

Then VM9. Each video data of 9n is subjected to predetermined compression by the DAC 13, converted into an analog signal by the DAC 13, modulated with a carrier wave by the MOD 14, and transmitted to the telephone line 16 via the DSP 15.

On the other hand, on the other party's side, the received signal via the telephone line 16 and DSP 15 is demodulated by a demodulation circuit (hereinafter referred to as DEM) 171C, converted into a digital signal in ADC 18, and then expanded in an expansion circuit (hereinafter referred to as EXP) 19. According to the judgment of μCP6, the signal indicating the selection period T of the first arriving frame number n1 is set to 5TG7. 5EL8 starts the same selection operation as the sending side.

The video data that then arrives is DEM17. ADC1
13, VML~9n is stored in μCP6 card vM91~9n via EXP19 and SEL8.
Similar to the sending side, video data representing a plurality of still images is stored individually and sequentially therein.

Then, DCTlo is the same as the sending side <5EL8 via VM9. In order to sequentially read out the contents of ~9n and send them to DPMll, DPMll1 repeatedly displays the same still images as those on the sending side for n frames in a row, each of which is repeated for a fixed time period T.

In addition, when transmitting and receiving only a still image for one frame, the Shoshu 5TG7 is stopped and the 8EL8 is in the state where the VM9t is selected, so the video data captured by the CAMIK is transmitted and received according to the control of the μcp6. After updating the contents one frame at a time, VM9. Since the contents of this will be displayed sequentially by DCTlo and DPMl 1, the operator will select the still image to be sent among these images and operate the imaging key in KPJ. Then, the video data of the image being displayed at this time is
9□It is permanently memorized.

Next, if you operate the send key in KPJ, only the contents of 7M91 will be sent in the same way as above, and on the receiving side, this video data will be stored only in VM 9, so a still image for one frame will be displayed. will be carried out.

Therefore, it is optional to transmit and receive video data for only one frame, and compatibility with existing video telephones can be ensured.

In addition, if the selection period T is made a little longer than several tens of meters, an effect similar to that of a simple moving image display can be obtained.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, video data representing a plurality of still images is sequentially transmitted, each received video data is individually stored in an image memory, and these contents are stored for each video data. By sequentially reading out the video data at a predetermined period, displaying each read video data for a certain period of time, and repeating this process, the apparent resolution is improved and it is compatible with existing videophones. compatibility can also be ensured, resulting in remarkable effects in videophones for various purposes.

[Brief explanation of the drawing]

The figure is a block diagram showing an embodiment of the present invention. 1...Video camera, 6...Microcomputer, 7...Switching timing generation circuit, 8...-
Selector, 91-9n... Image memory, 11...
・Display monitor.

Claims (1)

[Claims] A videophone that transmits and receives still images via a telephone line sequentially transmits video data representing a plurality of still images, stores each of the received video data individually in an image memory, and stores the contents of the image memory. A method for improving the resolution of a videophone, characterized in that each of the video data is sequentially read out at a predetermined period, each of the read video data is displayed for a certain period of time, and the reading and display are repeated. .