JPH04237289A - Picture transmitter - Google Patents

Abstract

PURPOSE:To send a picture signal fetched by a camera section to a picture receiver in a short period. CONSTITUTION:A picture compression section 14 compresses a picture signal fetched by a camera section 11 and a transmission D/A converter section 15 modulates the picture signal compressed as above into a a luminance signal representing the brightness of a picture element comprising an analog signal and a compression signal representing the compressed plural picture elements comprising digital signal and they are sent to a picture receiver 2. Thus, the system is most suitable for a burglar proof equipment or the like requiring immediacy.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an image transmission device.
In particular, the present invention relates to an image transmission device having an image transmission device and an image reception device.

0002

[Prior Art] Conventional technology of this type involves converting the frequency of an image signal captured from a camera section of an image transmitting device when transmitting it to an image receiving device via a transmission path with a narrow frequency band. , there is a method of transmitting it as a low-speed analog signal.

0003

[Problems to be Solved by the Invention] However, in the conventional image transmission device described above, since the image signal is not compressed, the image signal is captured by the camera section and then transmitted to the image receiving device. It takes a long time to finish. For this reason, for example, when used in a security monitor camera, it takes a long time after an abnormality occurs until the image receiving device detects the abnormality, resulting in a delay in taking necessary measures. This problem made it difficult to use for crime prevention purposes. Furthermore, when used in a monitoring device that performs monitoring by switching between a plurality of cameras, it takes a long time for the image receiving device to grasp the situation, so there is a problem in that appropriate monitoring cannot be performed. The present invention has been made in view of the actual situation in the prior art, and an object of the present invention is to provide an image transmission device that can shorten the transmission time of image signals.

0004

[Means for Solving the Problems] In order to achieve this object, the present invention provides an image transmitting device that compresses and transmits an image signal captured from a camera unit, and an image transmitting device that compresses and transmits an image signal taken in from a camera unit, and an image transmitting device that compresses and transmits an image signal that is received from a camera unit. In addition, in an image transmission device equipped with an image receiving device that reproduces and displays the uncompressed image signal,
The image signal transmitted from the image transmitting device is composed of a luminance signal consisting of an analog signal and a compressed signal consisting of a digital signal.

[0005]

[Operation] Since the present invention is configured as described above, compression is applied to the image signal captured from the camera section, and the compressed image signal, that is, the luminance signal consisting of an analog signal indicating the luminance of a pixel, and a plurality of luminance signals are combined. An image signal composed of a compressed signal composed of a digital signal indicating that the pixel is compressed is transmitted to an image receiving device. The image receiving device expands the received compressed image signal and reproduces and displays the image signal before compression. Thereby, the amount of information transmitted from the image transmitting device can be reduced, and therefore the transmission time of the image signal can be shortened.

[0006]

[Embodiments] Hereinafter, embodiments of the present invention will be explained based on the drawings. FIG. 1 is a block diagram showing an embodiment of the image transmission apparatus of the present invention, FIG. 2 is an explanatory diagram showing image information captured by a camera section, and FIG. 3 is an explanatory diagram showing the waveform of an image signal to be transmitted. Note that the minimum block in FIG. 2 indicates pixel information of one dot, which is the minimum unit of image information.

The image transmission apparatus of this embodiment shown in FIG.
It consists of an image receiving device 2 connected via. The image transmitting device 1 includes, for example, a camera section 11 that captures an image inside a car (not shown), and a camera section 1
Input A/D that digitizes the image signal output from 1
A conversion unit 12, a transmission image storage unit 13 that stores a digitized image signal, an image compression unit 14 that performs compression processing on the stored image signal, and a transmission D/A that converts the compressed image signal into an analog signal. It includes a conversion section 15 and a transmission line control section 16 that transmits an image signal to the image receiving device 2 via a telephone line 19. On the other hand, the image receiving device 2 includes a receiving line control section 21 that receives an image signal transmitted via a telephone line 19, and a receiving A/D converting section 22 that digitizes the received image signal. An image decompression unit 23 that performs decompression processing on the image signal to make it into an uncompressed image signal, a reception storage unit 24 that stores the decompressed image signal, and an output D/A conversion that extracts the stored image signal and converts it into an analog signal. section 25, and a display section 25 that displays an analog image signal.

In this embodiment, the camera unit 11 that captures the image inside the car outputs the image as an image signal to the input A/D converter 12.
digitizes the image signal. The transmission image storage section 13 temporarily stores the digitized image signal, and the image compression section 14
extracts the image signal stored in the transmission image storage unit 13, compresses this image signal, and then sends it to the transmission D/A.
It is output to the converter 15. Of the compressed image signals, the transmission D/A converter 15 converts a luminance signal indicating the luminance of a pixel into an analog signal representing the amplitude of a waveform, and a compressed signal indicating that a plurality of pixels are compressed, into a phase signal. Modulate it into a digital signal that is expressed as a change. Next, the transmission line control unit 16 transmits the compressed image signal to the image receiving device 2 via the telephone line 19. On the other hand, in the image reception device 2, the reception line control section 21 receives the compressed image signal transmitted from the image transmission device 1, and the reception A/D conversion section 22 digitizes the received image signal. Next, the image decompression section 23 performs decompression processing on the image signal composed of the luminance signal and the compressed signal to reproduce the uncompressed image signal, and the reception storage section 24 stores the decompressed compressed signal. Output D/A converter 25
extracts the stored image signal and converts it into an analog signal, and the display unit 21 displays an image based on the analog image signal.

Furthermore, the image signal compression method performed by the image compression section 14 is a block encoding method, and among the images 30 captured by the camera section 11 shown in FIG.
2, 53, 54, 56, 57, 58, and 59 are pixels that are not compressed, and one pixel is represented by one code. 55
, 60, the four pixels have almost the same brightness, and the four pixels are compressed and expressed as one code. 61, the 16 pixels have almost the same brightness, and the 16 pixels are compressed and represented by one code. This image 30 has a transmission waveform shown in FIG. 3. 51, 52, 53, 54, 56, 57, 58, and 59 represent cases in which one pixel is represented by one code, and four pixels are represented by one code.
If expressed as a code, send a waveform with a phase change of 180 degrees from the previous code, such as 55 and 60, and convert 16 pixels into 1
When expressed as a code, the phase change is performed twice as shown in 61. In this way, the presence or absence of a phase change is encoded as the presence or absence of compression, and the amplitude of each waveform is encoded as the luminance signal of the pixel.

0010

[Effects of the Invention] Since the present invention is constructed as described above, the transmission time of image signals can be shortened, and therefore,
For example, even when employed in a crime prevention device that requires quick response, the image receiving device side can quickly grasp the situation and take appropriate measures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an image transmission device of the present invention.

FIG. 2 is an explanatory diagram showing image information captured by a camera unit.

FIG. 3 is an explanatory diagram showing the waveform of a transmitted image signal.

[Explanation of symbols]

1 Image transmission device 2 Image receiving device 11 Camera part 12 Input A/D conversion section 13 Transmission image storage unit 14 Image compression section 15 Transmission D/A converter 22 Reception A/D conversion section 23 Image decompression section 24 Reception storage unit 25 Output D/A conversion section 26 Display section

Claims (1)

[Claims] 1. An image transmitting device that compresses and transmits an image signal taken in from a camera unit, and an image receiving device that expands the received compressed image signal and reproduces and displays the image signal before compression. An image transmission device comprising: the image signal transmitted from the image transmission device;
An image transmission device comprising a luminance signal consisting of an analog signal and a compressed signal consisting of a digital signal.