JPH05153567A - Moving picture coder - Google Patents

Abstract

PURPOSE:To improve the picture quality of a picture area desired to be noticed in the motion picture code. CONSTITUTION:A coordinate of an object to be noticed by a coordinate detection section 6 is detected and coordinate information 14 is outputted to an object tracing section 7. An area of an object of a position is segmented based on the coordinate information and a video signal 8 by the object tracing section 7, the object is traced and corrected coordinate information 15 of the traced object area is outputted. A quantization control section 3 calculates a quantization step size based on the corrected coordinate information from the object tracing section and on a transmission buffer residual quantity 12 and gives a small quantization step size to an area of the noted and traced object to reduce distortion of a picture of the area of the traced object and to improve the picture quality.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a video conference system,
The present invention relates to a moving picture coding device used for videophones, surveillance devices, and the like.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing the configuration of a conventional moving picture coding apparatus. In FIG. 2, 1 is a moving picture coding unit, which is a video signal 8 from a camera or a recording medium (VTR or the like). And the quantization step size 13 from the quantization controller 3 are input, and the encoded signal 9 is output. A transmission buffer unit 2 receives the coded signal 9 as an input, and outputs a coded signal 10 delayed according to the transmission rate of the line and a transmission buffer residual amount 12. A moving picture decoding unit 4 receives the coded signal 10 as an input and outputs a video signal 11. A display unit 5 receives the video signal 11 and displays an image. The quantization control unit 3 receives the transmission buffer residual amount 12 as an input, calculates a quantization step size 13, and sends it to the moving image encoding unit 1. Output.

Next, the operation of the moving picture coding apparatus will be described. In FIG. 2, a moving picture coding unit 1 (for example, C
CITT Recommendation H.264 An encoding device such as 261) takes the difference between the predicted value of the video signal 8 and the predicted value of the motion image, and outputs the discrete cosine transform (DCT) in block units of 8 pixels x 8 lines for the prediction error. Is quantized by compressing the amount of information based on the quantization step size 13 from the quantization control unit 3, variable-length coded, and then output as a coded signal 9.

The transmission buffer unit 2 temporarily stores the coded signal 9 and outputs it as a coded signal 10 according to the transmission rate of the line.

Further, the transmission buffer unit 2 counts the code amount accumulated in the buffer, and the transmission buffer residual amount 12
Output as. The quantization control unit 3 calculates the quantization step size from the transmission buffer residual amount 12 (for example, determines the quantization step size in proportion to the transmission buffer residual amount), and as the quantization step size 13, the moving image coding unit. Output to 1. Then, the moving picture decoding unit 4 performs the reverse process of the moving picture coding unit 1 on the coded signal 10 having the compressed information amount to release the information amount compression, and decodes it to obtain the video signal 11.
Is output to the display unit 5. The display unit 5 displays the video signal 11 on the video monitor.

As described above, the conventional moving picture coding apparatus can also carry out the information amount compression transmission of the entire area of the image.

[0007]

However, in the above-mentioned conventional moving picture coding apparatus, if a high information amount compression is performed and the transmission speed of the line between the coding unit side and the decoding unit is lowered, the coded signal 9 is transmitted. The buffer remaining amount is increased, and the entire quantization region of the image is increased so that the quantization step size of encoding is increased so that the transmission buffer remaining amount is reduced.
Since the quantization control is performed in, there is a problem that the entire region including the region of interest becomes a distorted image.

The present invention solves such conventional problems, and an object of the present invention is to provide an excellent moving picture coding apparatus capable of improving the image quality of a region of interest.

[0009]

According to the present invention, when a video signal is formed into a coded signal by a moving picture coding unit, the transmission buffer remains when the coded signal is temporarily delayed by the transmission buffer unit. The amount is input to the quantization control unit to calculate the quantization step size, the moving image coding unit quantizes the variable based on the quantization step size, and the variable length coding is performed to the moving image coding unit. In a moving image coding device that displays an image as a video signal on a display unit, a coordinate detection unit that detects the coordinates of a specific area of the image displayed on the display unit, and coordinate information detected by the coordinate detection unit. From the video signal, a region of the target object at the same position as the coordinate information is cut out, the target object is tracked, and an object tracking unit that outputs corrected coordinate information of the tracked region of the target object to the quantization control unit. Prepare and fix from the object tracking unit And coordinate information, with at the transmission buffer residue from the transmission buffer section, the quantization control unit is characterized in that to calculate the quantization step size.

[0010]

According to the present invention, the coordinate detection unit detects the coordinates of the target object of interest and outputs the coordinate information to the object tracking unit. The object tracking unit cuts out the area of the target object at the same position from the coordinate information and the video signal, tracks the target object, outputs the corrected coordinate information of the tracked target object area, and the quantization control unit By calculating the quantization step size from the corrected coordinate information from the object tracking unit and the transmission buffer residual amount, and giving a small quantization step size to the area of the target object that is focused and tracked, the area of the tracked target object is The image distortion is reduced to improve the image quality.

[0011]

1 is a block diagram showing a configuration of an embodiment of the present invention. In FIG. 1, 6 is a sensor arranged on a video monitor of a display unit 5 for pointing a target object of interest. , A coordinate detector that senses its position,
Reference numeral 7 denotes an object tracking unit that outputs the corrected coordinate information 15 from the coordinate information 14 from the coordinate detection unit 6 and the video signal 8 to the quantization control unit 3.

Other than the above, the same functional blocks as those shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

Next, the operation of the above embodiment will be described.
The moving picture coding unit 1 (for example, a coding device such as CCITT Recommendation H.261) takes the difference between the video signal 8 and the predicted value of the moving picture, and in units of blocks of 8 pixels x 8 lines with respect to the prediction error. Discrete Cosine Transform (DCT: Discrete Co
The sine tranformed output is quantized by compressing the amount of information based on the quantization step size 13 from the quantization control unit 3, quantized and variable-length coded, and then output as a coded signal 9. The transmission buffer unit 2 temporarily stores the encoded signal 9,
The encoded signal 10 is output according to the transmission rate of the line. Further, the transmission buffer unit 2 counts the code amount accumulated in the buffer and outputs it as the transmission buffer residual amount 12.

The moving picture decoding section 4 performs the reverse processing of the moving picture coding section 1 on the coded signal 10 having the compressed information quantity to release the compression of the information quantity, and decodes it to obtain a video signal 11. Output to the display unit 5. The display unit 5 displays the video signal 11 on the video monitor.

The above operation is similar to that of the conventional example. In this embodiment, the coordinate detection unit 6 has a sensor arranged on the video monitor of the display unit 5, and points a target object of interest on the video monitor (for example, coordinates x ₀ , y ₀ to x. _1, the y ₁₎ senses the position by, and output as the coordinate information 14. The object tracking unit 7 cuts out the area of the target object of interest from the video signal 8 and the coordinate information 14 of the target object of interest, tracks the moving object, and corrects the coordinates of the tracked target object area. Output as.

The quantization control unit 3 calculates a quantization step size 13 from the transmission buffer residual amount 12 from the reverse transmission buffer unit 2 and the corrected coordinate information 15 from the object tracking unit 7,
It is output to the moving picture coding unit 1. Here, the calculation of the quantization step size 13 is realized by giving a small step size preferentially to the target object region of interest and giving a large step size to the other regions. For example, if the transmission buffer residual amount 12 is B, the quantization step size 13 in the target object area is QA, and the quantization step size 13 outside the target object area is QB, the relationship between them is expressed as follows. Can be done (two examples below).

(1) QA = α, QB = β × B (α and β are constants, α is a small step size) (2) QA = α × B, QB = β × B (α and β are constants, α <
β) As described above, according to the above-described embodiment, the coordinate detection unit 6 detects the coordinates of the target object of interest, and the object tracking unit 7 cuts out the area of the target object from the coordinate information 14 and the video signal 8 and performs tracking. Output the coordinates of the tracked target object of interest, and the quantization controller 3 gives priority to the target object area of interest from the corrected coordinate information 15 of the tracked target object of interest and the transmission buffer residual amount 12. By controlling the quantization step size to be small, the image quality of the region of interest can be improved.

[0018]

As described above, in the moving picture coding apparatus of the present invention, the coordinate detecting section detects the coordinates of the target object of interest, and the object tracking section detects the coordinate information and the image detected by the coordinate detecting section. Based on the signal, the region of the target object of interest is cut out and tracked, the corrected coordinate information of the tracked target object of interest is output, and the quantization control unit corrects the coordinate information of the tracked target object. Since the control is performed such that a small quantization step size is preferentially given to the target object area based on the remaining amount of the transmission buffer from the transmission buffer unit, there is an effect that the image quality of the desired area can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a moving picture coding apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional moving image encoding device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Moving image encoding part, 2 ... Transmission buffer part, 3 ... Quantization control part, 4 ... Moving image decoding part, 5 ... Display part,
6 ... Coordinate detection unit, 7 ... Object tracking unit, 8, 11 ... Video signal, 9, 10 ... Encoded signal, 12 ... Buffer residual amount, 13
… Quantization step size, 14… Coordinate information, 15… Corrected coordinate information.

Claims (1)

[Claims] 1. When a video signal is created into a coded signal by a moving picture coding unit, the remaining amount of the transmission buffer when the coded signal is temporarily delayed by the transmission buffer unit is input to the quantization control unit. Then, the quantization step size is calculated, and the moving picture coding unit quantizes based on the quantization step size, and after variable length coding, the moving picture coding unit displays an image on the display unit as a video signal. In the moving image encoding device for displaying, the coordinate detection unit that detects the coordinates of a specific area of the image displayed on the display unit, the coordinate information detected by the coordinate detection unit, and the video signal, the coordinate information. A region of the target object at the same position as that is cut out, the target object is tracked, and an object tracking unit that outputs the corrected coordinate information of the tracked region of the target object to the quantization control unit, and from the object tracking unit Corrected coordinate information and the transmission bar With in a transmission buffer residue from the file unit, the quantization control unit is moving image coding apparatus is characterized in that to calculate the quantization step size.