JP2610359B2 - Moving image area determination device for image processing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image region including a plurality of pixels, which is a moving image region in which an image changes for each temporally continuous frame or the like, or a stationary image region in which the image does not change. A moving image area determination device that determines whether an image is an image region is mainly applied to an image processing device such as an image data transmission device that mainly transmits only image data of a moving image region.

2. Description of the Related Art As an example of a conventional moving image region determination device, a moving image region determination device applied to an image data transmission device will be described with reference to FIG.

In FIG. 5, 500 and 501 represent time (t−
An image frame memory for storing the input video signal of the frame F (t-1) in 1), and the frame F at time (t) one frame time after the time (t-1).
(T) an image frame memory for storing the input video signal,
502, based on the video signals stored in the image frame memories 500 and 501, performs a difference calculation of the video signal for each pixel block of 8 × 8 pixels, for example. A moving image block determining unit that determines whether the moving image block is a moving image block or a still image block that has not changed, and outputs moving image block determination information. Is a sending unit that sends out.

The moving image block determination unit 502 compares the video signal with the corresponding pixel block in the video signal one frame time ago for each pixel block, and when the video signal has changed significantly, Is determined to be a moving image block. Sending unit 50
In the method 3, the information amount of the video signal to be transmitted can be reduced by transmitting the video signal of only the moving image block based on the determination.

However, in the moving image area determination device as described above,
If the input video signal contains noise components,
Since the correlation between the input video signals between the frames F (t-1) and F (t) is reduced, the difference between the video signals is increased, and even a still image area may be erroneously determined as a moving image area. . Therefore, there is a problem that the determination accuracy tends to be low due to the influence of noise components and the like included in the input video signal.

As described above, when a pixel block that should be originally determined to be a still image block is erroneously determined to be a moving image block, for example, when applied to an image data transmission device that mainly transmits a video signal of only a moving image block, In this case, redundant image data is transmitted, which leads to a decrease in transmission capability.

The present invention has been made in view of the above points, and improves the accuracy of determining a moving image region and a still image region even when a noise component, particularly a relatively short-time transient noise component is included in an input video signal. It is an object of the present invention to provide a moving image area determination device of an image processing device that can perform the processing.

Means for Solving the Problems In order to achieve the above object, the present invention is an apparatus that determines whether each block on an image frame including a plurality of pixels is a moving image area or a still image area, Based on the difference in video signal between the block on the image frame to be processed (the block of interest) and the corresponding block on the immediately preceding image frame (the immediately preceding block), each block of interest is a moving image area or a still image area. A main determination unit that determines whether the block is of interest, and a determination correction unit that corrects the determination by the main determination unit. A first sub-judgment unit for judging whether the immediately subsequent block is a moving image area or a still image area based on a difference between the respective video signals, A second sub-determining unit that determines whether the immediately subsequent block is a moving image region or a still image region based on a difference between the respective video signals from the immediately following block, and a block of interest determined by the main determining unit to be a moving image region And all the blocks around the block of interest are determined to be still image areas, and the first sub-determining unit determines that the block immediately after the block of interest is a moving image area. And a correction unit that corrects the block of interest to be a still image area when the second sub-determination unit determines that the block immediately following the block of interest is a still image area. It is characterized by.

Operation With the above configuration, the main determination unit determines whether each block of interest is a moving image area or a still image area based on a difference between each video signal of the block of interest and the corresponding immediately preceding block, and corrects the determination. The means corrects the determination.

Even when the main determination unit determines that the block of interest is a moving image region, the determination correction unit determines that all blocks around the block of interest are still image regions, and When it is possible to determine that the corresponding immediately following block is a moving image area based on the block and that the corresponding immediately following block is a still image area based on the corresponding immediately preceding block, a relatively short time It is determined that a transient noise component is included, and the block of interest is corrected to be a still image area.

Embodiment As an embodiment of the present invention, an example of a moving image area determination device applied to an image data transmission device will be described.

FIG. 1 is a block diagram showing the configuration of a transmission device for image data.

In FIG. 1, 100 to 102 represent times (t−1), (t), (t +
Frames F (t-1), F (t), F (t) in 1)
+1) a cascade-connected image frame memory for storing video signals; and 103 a moving image block memory based on the video signals of frames F (t-1) and F (t) stored in the image frame memories 100 and 101. The moving image block main determination unit 104 that outputs the determination information Ds (t) includes image frame memories 101 and 10.
2 based on the video signals of the frames F (t) and F (t + 1) accumulated in the moving image block first sub-determination information Dh (t +
The moving image block first sub-determining unit 105 that outputs 1) outputs the frame F (t−t) stored in the image frame memories 100 and 102.
1), the moving image block second sub-determining section 106 that outputs moving image block second sub-determining information Dh (t + 1) ′ based on the video signal of F (t + 1);
(T) a moving image block main judgment information correction unit that outputs moving image block judgment information D (t) based on moving image block first sub-judgment information Dh (t + 1) and moving image block second judgment information Dh (t + 1) ′; 107 is moving image block determination information D
Based on (t), the transmitting unit transmits only the video signal of the moving image block.

The image frame memory 102 stores one frame of input video signal every frame time. The image frame memories 101 and 100 are configured to transfer and accumulate the video signals stored in the image frames 102 and 101 every one frame time. That is, the image frame memories 100, 101, 102
In this order, the video signal after one frame time is stored in this order.

The moving image block main determination unit 103, as shown in FIG.
For example, for a pixel block bij (t) consisting of 8 × 8 = 64 pixels q00 to q77, i-th from the left end and j-th from the top in frame F (t), frame F (t−1)
Is the difference Eaij from the pixel block bij (t-1) consisting of 64 pixels p00 to p77 at the same position, The difference Eaij is compared with a preset threshold Vth, and if Eaij ≦ Vth, the pixel block
bij (t) is determined to be a pixel block in which a video image does not change between frames F (t−1) and F (t), and moving image block main determination information dsij (t) = 0, Eaij
If> Vth, it is determined that the image is a pixel block in which the video is changing, and the moving image block main determination information dsij (t) = 1. Then, the same determination is performed for all the pixel blocks, and the moving image block main determination information Ds for one frame is obtained.
(T) is accumulated and output.

In addition, the moving image block first sub-determining unit 104 and the moving image block second sub-determining unit 105 similarly perform the processing on the frame F (t),
F (t + 1) or frames F (t−1), F (t
+1), it is determined whether or not the image has changed for each pixel block, and the moving image block first sub-determination information Dh is determined.
(T + 1) or the moving image block second determination information Dh (t +
1) 'is stored and output.

The moving image block main judgment information correction unit 106 includes the moving image block main judgment information Ds (t), the moving image block first sub judgment information
Dh (t + 1) and moving image block second sub-determination information Dh
Based on (t + 1) ′, each pixel block bij
For each (t), if dsij (t) = 0 and dsij
Even if (t) = 1, dhij (t) = 1 and dhij (t) ′ = 0, and the pixel block bij
If all of the moving image block main determination information dsxx (t) of the pixel block bxx (t) surrounding (t) is 0, it is determined that the pixel block bij (t) is a still image block, and While the block determination information dij (t) = 0,
In other cases, the pixel block bij (t) is determined to be a moving image block and moving image block determination information dij
(T) = 1. Then, the same determination is performed for all the pixel blocks, and is accumulated and output as moving image block determination information D (t) for one frame.

In the above configuration, the input video signal for one frame is sequentially transferred to the image frame memory 10 every frame time.
Transferred to 2, 101, 100 and stored. That is, for example, as shown in FIG. 3, when the video signal of the frame F (t) is stored in the image frame memory 101, the frame F is stored in the image frame memories 100 and 102, respectively.
(T) and a frame F (t
-1) and F (t + 1) are stored.

Therefore, the moving image block main determination unit 103 determines whether the frames F (t−1), F
Based on the video signal of (t), each pixel block
For each bij (t), a difference Eaij from the corresponding pixel block bij (t-1) is obtained by the above-described operation, and this difference Eaij
aij is compared with the threshold value Vth to determine the pixel block bij (t).
Is changed with respect to the image of the pixel block bij (t-1). The video block main determination information dsij (t) for all the pixel blocks bij (t) obtained by this determination is converted to the video block main determination information Ds.
(T) and output to the moving image block main determination information correction unit 106.

Similarly, the moving image block first sub-determining unit 104 and the moving image block second sub-determining unit 105
(T), between F (t + 1) or frame F (t−
It is determined whether or not the image has changed for each pixel block between 1) and F (t + 1), and the video block first sub-determination information dhij (t + 1) or the video block second sub-determination information for all the pixel blocks dhij (t + 1) ′,
It is stored as the moving image block first sub-determination information Dh (t + 1) or the moving image block second sub-determination information Dh (t + 1) ′, and is output to the moving image block main determination information correction unit 106.

The video block main determination information correction unit 106 includes the video block main determination information Dsij (t), the video block first sub-determination information Dhij (t + 1), and the video block second sub-determination information
Each pixel block based on Dhij (t + 1) '
The following determination is made for each bij (t).

That is, the pixel block bi in the frame F (t)
If j (t) is a still image block in which the video has not changed much with respect to the frame F (t−1), the moving image block main determination information dsij (t ) = 0, the moving image block main judgment information correction unit 106 sets the moving image block judgment information dij (t) = 0.

On the other hand, if the pixel block bij (t) is a moving image block, the moving image block main determination information dsij (t) = 1. Here, even if the pixel block bij (t) is not a moving image block, the input image If the signal contains noise components, the image changes for each frame.
Also, the moving image block main determination information dsij (t) = 1 may be satisfied. Therefore, the video block main determination information correction unit
As shown in FIG. 4, reference numeral 106 denotes all the pixel blocks bxx around the pixel block bij (t) where dsij (t) = 1 even if the moving image block main determination information dsij (t) = 1.
In the case of (t), dsxx (t) = 0, video block first sub-determination information dhij (t + 1) = 1, and video block second sub-determination information dhij (t + 1) ′ = 0 Is moving image block determination information dij (t) = 0.

That is, the correlation of the input video signal between the frames F (t−1) and F (t) becomes small due to the influence of the noise component included in the input video signal, usually in a small range on the image. Since the image is often a transient image of a relatively short time, the change of the image is not large between the frames F (t−1) and F (t + 1), and the image of the surrounding pixel block is not much. It does not change. Therefore, in such a case, as described above, for each pixel block, the degree of change of the image between the three temporally successive frames and the image of the pixel block around the pixel block By determining whether a still image block is a moving image block based on the degree of change, it is possible to prevent a still image block from being erroneously determined to be a moving image block.

Also, when the moving image block main determination information dsij (t) = 1 and all the pixel blocks around the pixel block bij (t) are not still image blocks, and when the moving image block main determination information dsij (t) = 1. And the pixel block bij
Dsxx in all pixel blocks bxx (t) around (t)
Even when (t) = 0, the second sub-determination information dhij (t +
1) If '= 1 or the moving image block first sub-determination information (dhij (t + 1) and the moving image block second sub-determining information dhij (t + 1)' are both 0, the moving image block determination information dij (T) = 1, that is, in such a case, since the image changes from frame to frame is not due to the noise component included in the input video signal,
It is determined that the pixel block bij (t) is a moving image block.

The transmitting unit 107 is based on the video block determination information D (t) output from the video block main determination information correction unit 106,
A video signal of only the pixel block determined to be a moving image block is output as an output video signal. In the output video signal, the determination of the moving image block is performed with high accuracy as described above, so that the information amount is reduced and the deterioration of the image quality is also reduced.

Note that, in the present embodiment, an example has been described in which the absolute value of the difference between the corresponding pixels is summed up when calculating the difference between the pixel blocks. However, the present invention is not limited to this. Weighting may be performed in accordance with the level, and the sum may be performed.

Further, the difference between the pixel blocks may be a value obtained for a luminance signal, a color signal, a color difference signal, or the like.

Advantageous Effects of the Invention As described above, according to the present invention, the main determination unit determines the target block bij (t) and the immediately preceding block bij (t-
Based on the difference between the respective video signals and 1), it is determined for each block of interest bij (t) whether it is a moving image area or a still image area, and the determination correcting means corrects the determination.

This judgment correcting means is provided by the main judgment means,
Even when bij (t) is determined to be a moving image area, all blocks around the target block bij (t) are determined to be still image areas, and the target block bij (t ), It is possible to determine that the immediately following block bij (t + 1) is a moving image area, and
When it is possible to determine that the immediately succeeding block bij (t + 1) is a still image area based on (t-1), it is determined that the target block bij (t) contains a noise component, and the target block bij (t) is determined. ) Is corrected as a still image area. Accordingly, even if the main image determining unit erroneously determines that the arrival block bij (t) is a moving image region because the still image region includes a relatively short-term transient noise component, The erroneous determination is corrected by the determination correction means, and the area is determined to be a still image area.

Therefore, even when the video signal includes a relatively short-term transient noise component, it is possible to prevent the erroneous determination between the moving image region and the still image region from occurring and to increase the determination accuracy. It has the effect of being able to.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an image data transmission device to which a moving image area determination device according to one embodiment of the present invention is applied, FIG. 2 is an explanatory diagram showing an example of a pixel block, and FIG. FIG. 4 is an explanatory diagram showing a relationship between a video signal stored in a memory and each moving image block determination information, FIG. 4 is an explanatory diagram showing a determining operation of a moving image block main determination information correcting unit, and FIG. 1 is a block diagram showing a configuration of an image data transmission device to which is applied. 100, 101, 102... Image frame memory, 103... Video block main determination unit, 104... Video block first sub-determination unit, 1
05: video block second sub-determination unit, 106: video block main determination information correction unit, 107: transmission unit

Claims (1)

(57) [Claims] An apparatus for determining, for each block on an image frame including a plurality of pixels, a moving image area or a still image area, comprising: a block on an image frame of interest (a block of interest); A main determination unit that determines whether each block of interest is a moving image area or a still image area based on a difference between respective video signals with a corresponding block (immediately preceding block) on an image frame; Determination correction means for correcting the determination according to the following. The determination correction means determines whether the immediately following block is based on the difference between the video signal of the block of interest and the corresponding block on the immediately following image frame (the immediately following block). A first sub-determining unit that determines whether the block is a moving image area or a still image area; A second sub-determining unit that determines whether the block immediately after that is a moving image area or a still image area; and the main determining unit determines that the block of interest is a moving image area, and All the blocks are determined to be still image areas, and the first sub-determination unit determines that the block immediately after the block of interest is a moving image area, and the second sub-determination unit determines that A moving image area determination device for an image processing apparatus, comprising: a correction unit that corrects the block of interest to be a still image area when the block immediately after the block is determined to be a still image area. .