JP2833909B2 - Video encoding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture coding apparatus for coding a picture signal with high efficiency.

[0002]

2. Description of the Related Art Conventionally, this type of moving picture coding apparatus in a video conference system or the like has a function (picture) of synthesizing an analog transmission image input from a camera with a reception image and monitoring the transmission image on a reception monitor. (In-picture display), the size of the transmission image to be synthesized is fixed, and humans have determined ON or OFF by external control.

[0003]

According to the above-mentioned conventional method, when a received image is monitored by displaying a picture-in-picture, the movement of the received image changes drastically, and an image which changes on the television monitor from left to right and up and down is displayed. On the other hand, there was a drawback that hindered viewing. In addition, in the case of such a received image, it is necessary for a human to turn off the picture-in-picture display each time, and there is a disadvantage that it is very troublesome.

Accordingly, an object of the present invention is to provide a moving picture coding apparatus capable of displaying a combined picture having a size corresponding to the movement of a picture to be combined without human intervention.

[0005]

SUMMARY OF THE INVENTION A moving picture coding apparatus according to the present invention comprises an A / D converter for converting an analog image signal into a first digital image signal, and an output from the A / D converter having a high efficiency. A transmitting unit having an encoding circuit for encoding and outputting the data to the transmission path, a decoding circuit for efficiently decoding data received from the transmission path and outputting a second digital image signal, and an image synthesis control signal. An image synthesizing circuit that is controlled to synthesize the first digital image signal with the second digital image signal and outputs a digital synthesized signal; counts the amount of motion of the second digital image signal and determines the amount of motion; A motion amount detection circuit to be output, and a signal when the digital image signal is not synthesized by the image synthesis circuit and N kinds (N ≧ 2) of synthesis area sizes are controlled according to the motion amount from the motion amount detection circuit. Image synthesizing control circuit for outputting a total of M (M = N + 1) signals as the image synthesizing control signal, and a D / A converter for converting a digital synthesized signal output from the image synthesizing circuit into an analog signal And a receiving unit having:

In the moving picture coding apparatus according to the present invention, in the above-mentioned configuration, the motion amount detecting circuit receives the digital picture signal and delays the picture frame by one frame, and the frame memory output. A subtractor that calculates a frame difference from the digital image signal and outputs a difference value; and a motion amount counting circuit that outputs a motion amount by counting the difference value output by the subtractor. Is what you do.

Further, in the moving picture coding apparatus according to the present invention, in the above-described configuration, the picture synthesis control circuit inputs a motion amount and sets a threshold value of M stages corresponding to the M signals. And a holding circuit that holds the signal representing the threshold value for a certain period of time and outputs the signal as the control signal.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention. In this embodiment, in order to simplify the description, the description will be made assuming that the combined area size M is 4. However, the number of areas for which the size can be actually defined is N, and the other one means that the area size is 0, that is, there is no combination.

In FIG. 1, an analog image signal a input from an input terminal 1 is input to an A / D converter 2. A /
The (first) digital image signal b is output from the D converter 2 and input to the encoding circuit 3 and the image synthesizing circuit 8. The encoding circuit 3 sends the encoded data c which has been encoded with high efficiency to the transmission line output terminal 4. The encoded data d received from the transmission line input terminal 5 is input to the decoding circuit 6.
Efficiently decoded (second) digital image signal e
Is input to the motion amount detection circuit 7 and the image synthesis circuit 8.
The motion amount f output from the motion amount detection circuit 7 is input to the image synthesis control circuit 9, and outputs an image synthesis control signal g corresponding to the motion amount f to the image synthesis circuit 8. Image composition circuit 8
Is controlled by an image synthesis control signal g to synthesize the first digital image signal b with the second digital image signal e and output a digital synthesized signal h to the D / A converter 10.
An analog image signal i is output from the D / A converter 10,
It is sent from the output terminal 11.

In the motion detection circuit 7, the digital image signal e is input to a frame memory 71 and a subtractor 72. The frame memory 71 stores the digital image signal e at 1
The frame is delayed and output to the subtractor 72. Subtractor 72
Subtracts the digital image signal e from the image signal delayed by one frame from the frame memory 71 to obtain a difference signal j.
Is output to the motion amount counting circuit 73. Motion amount counting circuit 73
Then, the difference signal j is counted at regular intervals, and the value is output as a movement amount f.

In the image synthesizing control circuit 9, the motion amount f is input to a motion amount determination circuit 91. Motion amount determination circuit 91
Calculates the average value of the motion amount f for one frame of data, determines whether the average value is one of the four threshold values set in the present embodiment, and determines the determination result as 4 It outputs to the holding circuit 92 as a kind of control signal. Holding circuit 92
Holds an image synthesis control signal g to the image synthesis circuit 8 while holding four types of control signals so that the image synthesis area size and the synthesis ON / OFF are continued for a certain period of time.

FIG. 2 shows an image composition output to the image composition circuit 8 corresponding to four types of thresholds (A to D in this embodiment) with respect to the motion amount of the received image sent from the other party. FIG. 3 is a diagram showing an operation waveform diagram of a control signal g (g1 to g4), and FIG. 3 is a diagram showing a state of a combined area size of an image projected on a television monitor. To explain, (a) when the motion amount is larger than the threshold value A and smaller than the threshold value B, the digital image signal b is
The images are synthesized by size and projected on a TV monitor as a synthesized screen shown in FIG. (b) When the amount of motion is larger than the threshold value B and smaller than the threshold value C, the image synthesizing circuit 8 synthesizes the digital transmission image signal b in B size, and sets the synthesized image shown in FIG. It is projected on the monitor. (c) When the amount of motion is larger than the threshold value C and smaller than the threshold value D, the digital image signal b is synthesized in C size by the image synthesizing circuit 8, and the synthesized image shown in FIG. It is projected. (d) When the motion amount is larger than the threshold value D, the image synthesis control signal g is turned off and the image synthesis circuit 8 does not synthesize the digital image signal b, and the received image is not synthesized as shown in FIG. It is projected on the TV monitor as it is.

Although the case where M (= N + 1) is 4 has been described above, it is needless to say that the present invention is not limited to this. Also, N is limited to two or more.

[0014]

As described above, according to the present invention, since the size of the combined area of the transmission image and the combination ON / OFF are automatically switched with respect to the movement of the reception image sent from the other party, the change of the movement of the reception image is small. This has the effect of not obstructing viewing of an image that changes violently on the television monitor from top to bottom and left and right.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a moving image encoding device according to the present invention.

FIG. 2 is a diagram illustrating a relationship between an image synthesis control signal corresponding to a motion amount of a digital image signal and a screen synthesis size.

FIG. 3 is a diagram illustrating an example of each size of a composite screen.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 input terminal 2 A / D converter 3 encoding circuit 4 transmission line output terminal 5 transmission line input terminal 6 decoding circuit 7 motion amount detection circuit 8 image synthesis circuit 9 image synthesis control circuit 10 D / A converter 11 output terminal 71 frame memory 72 subtracter 73 motion amount counting circuit 91 motion amount determination circuit 92 holding circuit a analog image signal b digital image signal (first) c encoded data d encoded data e digital image signal (second) f Motion amount g Image synthesis control signal h Digital synthesized signal i Analog image signal j Difference signal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 7/15 H04N 5/265 H04N 7/24-7/68 G09G 5/14

Claims (3)

(57) [Claims] An A / D converter for converting an analog image signal into a first digital image signal, and an encoding circuit for highly efficiently encoding an output of the A / D converter and outputting the encoded signal to a transmission line. A transmitting unit, a decoding circuit for efficiently decoding data received from the transmission path and outputting a second digital image signal, and a second digital image signal controlled by an image synthesis control signal;
An image synthesizing circuit for synthesizing the first digital image signal with the digital image signal and outputting a digital synthesized signal, and a motion amount detecting circuit for counting the amount of motion of the second digital image signal and outputting the amount of motion And a signal indicating that the image synthesizing circuit does not synthesize the two digital image signals according to the amount of motion from the motion amount detecting circuit;
An image synthesizing control circuit for outputting a signal for controlling a kind (N ≧ 2) of synthesis area sizes as the image synthesizing control signal, and a D / A conversion for converting a digital synthesized signal output from the image synthesizing circuit into an analog signal A moving image encoding apparatus comprising: 2. A frame memory, wherein the motion amount detection circuit inputs the second digital image signal and delays it by one frame of an image frame, and a difference between an output of the frame memory and a frame of the second digital image signal. Take
2. The moving picture coding apparatus according to claim 1, further comprising a subtractor that outputs a difference value, and a motion amount counting circuit that counts the difference value output by the subtractor and outputs a motion amount. 3. The image synthesizing control circuit receives a motion amount as a stage of one threshold when there is no synthesizing of the two digital image signals, and sets a predetermined (N + 1)
A moving amount determining circuit for outputting a signal corresponding to a moving amount with respect to a threshold value of a step, and a holding circuit for holding the signal for a predetermined time and outputting the signal as the control signal; Device.