JP3590251B2 - Video signal processing apparatus and method for forming frame difference display signal - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a video signal processing apparatus, and more particularly to a video signal processing apparatus that forms an inter-frame difference display signal used for video signal processing such as high-efficiency encoding of a television signal, and a method therefor.
[0002]
[Prior art]
For example, in predictive coding, which is one of high-efficiency coding of a video signal such as a television signal, a signal of a current frame and a previous frame of the video signal is used as a prediction signal, and a difference between the current frame and the current frame is calculated. Is detected and transmitted as a prediction error. Since the inter-frame difference is directly related to the prediction accuracy and the degree of coding efficiency, it is desirable that the inter-frame difference can be observed and evaluated by some method. Conventionally, a computer simulation has been mainly used as a method of examining the inter-frame difference amount. Therefore, as a method for confirming and understanding the amount of inter-frame difference for a video signal processing device that actually performs inter-frame difference processing in real time, for example, a high-efficiency encoding device, it is necessary to check the degree of encoding efficiency obtained as a result. There was no suitable one. In addition, as an example of observing and grasping signal information used for prediction encoding in real time, the magnitude and direction of a motion vector used for motion compensation prediction are displayed as a color signal level and a hue change on a color monitor. There is only an example in Japanese Patent Application Laid-Open No. Hei 1-309598.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional technology, the problem is that it is not possible to display in real time the magnitude of the difference amount in the details of the image, the distribution on the image, the change in the difference due to the motion of the image, and visually grasp and evaluate the inter-frame difference. There was a point.
[0004]
The present invention provides a real-time visual display of the magnitude of the difference amount between frames, the distribution on the image, and the change due to the motion of the image on the actual image in parallel with the luminance signal, thereby enabling a visual grasp evaluation. It is an object of the present invention to provide a video signal processing device for forming an inter-difference display signal and a method thereof.
[0005]
[Means for Solving the Problems]
According to an embodiment of the present invention, there is provided a video signal processing apparatus for forming an inter-frame difference display signal representing a difference between two frames of an input video signal including a luminance signal and a color difference signal. A difference detection unit for obtaining a difference signal between two frames of the signal; and a difference signal insertion unit for interrupting the obtained difference signal to an output line of the color difference signal and outputting the signal to a first output terminal.
[0006]
In this device, the difference signal insertion means includes switching means for selectively setting the first and second connection states, and the switching means connects the color difference signal to the first output terminal in the first connection state. In the second connection state, the obtained difference signal may be connected to a first output terminal.
[0007]
Further, in this device, the color difference signal includes first and second color difference signals, and the switching means connects the first color difference signal to the first output terminal in the first connection state, and switches the second connection state to the second connection state. Then, it is preferable to connect a difference signal detected in place of the first color difference signal to the first output terminal.
[0008]
According to the present invention, there is also provided a method of processing a video signal for forming an inter-frame difference display signal representing a difference between two frames of an input video signal including a luminance signal and a color difference signal. And a step of interrupting the obtained difference signal to a color difference signal output line and outputting the signal.
[0009]
In this case, the method may include a step of visually displaying a signal obtained by interrupting the difference signal on the output line of the color difference signal as color signal information on the color image display device.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The embodiment of the video signal processing apparatus for forming the inter-frame difference display signal according to the present invention uses the signal of the current frame and the immediately preceding frame as the prediction signal, and detects the difference between the two to obtain the inter-frame difference. This is an inter-frame difference detection device that forms a difference signal. This can be advantageously applied, for example, to a high-efficiency coding apparatus of a predictive coding system for transmitting the inter-frame difference as a prediction error to a use apparatus.
[0011]
FIG. 1 is a functional block diagram showing an outline of a video signal processing apparatus for forming an inter-frame difference display signal according to an embodiment of the present invention. In the video signal processing apparatus according to the present embodiment, the luminance signal Y of the video signal and the color difference signals RY and BY are input to the input terminals 1, 2, and 3 in the form of digital type component color television signals, respectively. This is an inter-frame difference detection circuit that obtains a difference between two frames adjacent to each other on the time axis with respect to the luminance signal Y and outputs an inter-frame difference signal to its output 14. The illustrative embodiment is configured to detect inter-frame differences only for the luminance signal Y, but additionally or alternatively, for the color difference signals RY and BY. You may comprise so that a difference between frames may be calculated | required. The apparatus may also utilize, for example, a composite color television signal. In that case, a color decoder (not shown) is connected to the input terminals 1, 2, and 3.
[0012]
In this embodiment, the present invention is applied to a video signal processing apparatus using the inter-frame difference of the video signal. However, the present invention is not limited to this. For example, instead of the inter-frame difference, the inter-field difference may be used. It is needless to say that the present invention can also be applied to a video signal processing device using the difference of In this sense, in this specification, the term “frame” is typically used, but the term “frame” is to be interpreted broadly including a field.
[0013]
In FIG. 1, an input terminal 1 to which a luminance signal Y is supplied is connected to a frame memory 4 and one input of an inter-frame difference circuit 5 and an inter-frame signal processing circuit 6 for the luminance signal Y. The input terminals 2 and 3 to which the color difference signals RY and BY are respectively input are an inter-frame signal processing circuit 7 for the color difference signal RY and an inter-frame signal processing circuit for the color difference signal BY. It is connected to a circuit 8. In the present embodiment, the frame memory 4 is an image memory for storing at least one frame of the luminance signal data Y, and the output 20 outputs the luminance signal Y with a time delay of at least one frame. . This output 20 is connected to the other input of the inter-frame difference circuit 5 and the inter-frame signal processing circuit 6 for the luminance signal Y as shown. These circuits constitute an encoding circuit when the present apparatus is applied to a high-efficiency encoding apparatus.
[0014]
The inter-frame difference circuit 5 calculates a difference between the luminance signal of the current frame arriving at the input terminal 1 and the luminance signal of the frame one frame before output from the output 20 of the frame memory 4 and calculates the difference. A difference calculation circuit that outputs a represented frame difference output signal to an output 10. This difference calculation may be, for example, an operation of calculating a change amount of a corresponding pixel in two frames. Further, the inter-frame signal processing circuit 6 uses the difference between the luminance signal of the current frame input from the input terminal 1 and the luminance signal of the previous frame output from the frame memory 4 to perform, for example, inter-frame prediction coding. A signal processing circuit that performs signal processing and outputs the processed luminance signal to an output 14. Preferably, the signal processing circuit 6 further performs, for example, motion compensation prediction coding using a motion vector in order to increase the prediction accuracy of the coding, so that a highly efficient coded luminance signal output is obtained at the output 14. It may be. In this case, the inter-frame signal processing circuit 6 divides the video signal of one frame into a plurality of blocks having a predetermined number of pixels, obtains a correlation between frames for each block, and detects the direction and amount of movement of the pixel of interest. It is configured to
[0015]
Inter-frame signal processing circuits 7 and 8 for color difference signals RY and BY respectively perform signal processing such as inter-frame prediction coding, and output the processed color difference signals to outputs 12 and 16, respectively. It is a signal processing circuit. These circuits may perform, for example, motion compensation prediction coding using a motion vector in order to increase the prediction accuracy of coding, and may obtain a highly efficient coded color difference signal output.
[0016]
The output 10 of the inter-frame difference circuit 5 and, on the other hand, the output 12 of the inter-frame signal processing circuit 7 for the color difference signal RY in this embodiment are connected to corresponding inputs of the switching circuit 9 as shown in the figure. I have. The switching circuit 9 has two inputs 10 and 12, that is, an output signal 10 of the inter-frame difference circuit 5, for example, in response to an instruction of an operator or under the control of a control circuit (not shown) such as a processing device. And a selection circuit for selectively connecting one of the output signals 12 of the inter-frame signal processing circuit 7 of the color difference signal RY to the output 15 thereof. As can be seen, the switching circuit 9 functions as a difference signal insertion circuit that interrupts the inter-frame difference output signal of the luminance signal Y into the RY signal line. The present invention is not limited to this, and the output 16 of the inter-frame signal processing circuit 8 for the other color difference signal BY may be connected to the input 12 of the switching circuit 9. Note that, in the present invention, the switching circuit 9 is not always essential. For example, in an application example in which the inter-frame difference output signal 10 of the luminance signal Y is fixedly interrupted to the RY signal line, the switching circuit 9 is omitted and the output 10 of the inter-frame difference circuit 5 is output. What is necessary is just to connect to the apparatus output 15 directly.
[0017]
A utilization circuit 22 such as an image display device for visualizing a video signal such as a color monitor is connected to the output terminals 14, 15, and 16 of the device. When the present apparatus is applied to, for example, a composite color television signal, a color encoder (not shown) may be added to the output terminals 14, 15 and 16 of the apparatus. As described later in detail, the composite color television signal output from the color encoder includes an inter-frame difference signal as color signal information, which can be observed on a color monitor for the composite signal.
[0018]
In the operating state, the luminance signal Y and the color difference signals RY and BY are input to the input terminals 1, 2 and 3 of the apparatus in the form of digital data, respectively. The luminance signal Y input to the terminal 1 is applied to one input of the inter-frame difference circuit 5 and the inter-frame signal processing circuit 6 as a current frame input signal on the one hand, and is stored in the frame memory 4 on the other hand. The luminance signal data stored in the frame memory 4 is thereby delayed by one frame time, and is applied from its output 20 to the other input of the inter-frame difference circuit 5 and the inter-frame signal processing circuit 6 as a previous frame input signal. .
[0019]
The inter-frame difference circuit 5 performs an operation for calculating the difference between these two frame input signals, and an output signal 10 which is the inter-frame difference information of the luminance signal Y is obtained. Further, the inter-frame signal processing circuit 6 performs inter-frame predictive coding using a difference between these two frame input signals, and further performs motion compensation predictive coding using a motion vector in order to increase prediction accuracy. A highly efficient encoded luminance signal output is available at its output 14.
[0020]
The color difference signals RY and BY input to the input terminals 2 and 3, respectively, are subjected to required inter-frame signal processing by the corresponding inter-frame signal processing circuits 7 and 8, respectively. This inter-frame signal processing is the same as the processing performed by the inter-frame signal processing circuit 6 on the luminance signal Y.
[0021]
The inter-frame difference output signal 10 of the luminance signal Y and the output signal 12 of the inter-frame signal processing circuit 7 of the chrominance signal RY thus obtained are applied to the input of the switching circuit 9, respectively. In a normal case, since the switching circuit 9 is in the connection state opposite to that shown in the figure, the output signal from the inter-frame signal processing circuit 7 for the luminance signal RY passes to the output 15 as it is. In this state, the luminance signals Y and the color difference signals RY and BY are output to the output terminals 14, 15, and 16 of the apparatus, respectively, with high efficiency coding.
[0022]
One of the features of the present embodiment is that the switching circuit 9 interrupts the output line of one of the color difference signals R-Y of the luminance signal Y obtained by the inter-frame difference circuit 5 and outputs the color difference signal. This is connected to the terminal 15, and this signal 15 is used as a signal for displaying the difference between frames by a use device (not shown) such as a video monitor. For this reason, in this embodiment, the switching circuit 9 is switched under the control of an operator or under the control of a control circuit (not shown), and the RY output signal 12 from the inter-frame signal processing circuit 7 is substituted. Thus, the inter-frame difference output signal 10 of the luminance signal Y from the inter-frame difference circuit 5 is selected, and this is connected to the RY signal output terminal 15. Therefore, if an image display device such as a color monitor is connected to the outputs 14, 15, and 16 of the device, the inter-frame difference signal of the luminance signal Y interrupted on the RY signal line of the image is displayed on the monitor screen as color signal information. Observed directly at.
[0023]
FIG. 2 shows another embodiment of the present invention. The embodiment shown in FIG. 2 is the same as that shown in FIG. 1 except that the switching circuit 9 is replaced by a switching circuit 9a. In the figure, the same elements as those shown in FIG. 1 are denoted by the same reference numerals, and redundant description will be avoided. The switching circuit 9a in the present embodiment has two switching contacts 9-1 and 9-2, both of which are symbolically indicated by dotted lines in FIG. Alternatively, it is a selection circuit that, under the control of a control circuit (not shown) such as a processing device, selectively connects the illustrated connection state and the connection state opposite thereto in an interlocked manner. The output signal 10 of the inter-frame difference circuit 5 and the output signal 12 of the inter-frame signal processing circuit 7 for the color difference signal RY are connected to one connection circuit 9-1, and one of them is selectively output. Connect to 15. The other connection circuit 9-2 is connected to the output signal 13 of the inter-frame signal processing circuit 8 for the other color difference signal BY and a reference potential, for example, a ground potential. Is connected to its output 16.
[0024]
In an operating state, in a normal case, the switching circuit 9a is in a connection state opposite to that shown in the figure, and the contacts 9-1 and 9-2 output the color difference signals RY and BY respectively to the output terminals 15 and Pass through to 16. Thus, the luminance signals Y and the color difference signals RY and BY are output to the output terminals 14, 15 and 16, respectively, of the device, respectively.
[0025]
When it is desired to display an inter-frame difference, the switching circuit 9a is switched to the connection state shown in the drawing according to an operator's instruction or under the control of a control circuit (not shown). As a result, the connection circuit 9-1 selects the inter-frame difference output signal 10 of the luminance signal Y instead of the chrominance signal RY from the inter-frame signal processing circuit 7 and connects it to the output terminal 15; 9-2 separates the other color difference signal BY from the output terminal 16 side and connects it to the potential "0".
[0026]
Thus, the color information of the image observed on the color monitor (not shown) connected to the output terminals 14, 15 and 16 is only the inter-frame difference output signal 10 of the luminance signal Y. Therefore, the operator can more easily visually recognize the magnitude and distribution of the inter-frame difference amount, the change due to the movement of the image, and the like on the display screen.
[0027]
In each of the above-described embodiments, the inter-frame difference output signal of the luminance signal Y is interrupted to the RY signal line. However, the present invention is not limited to this. For example, as described above, an inter-frame difference output signal of the luminance signal Y may be configured to interrupt the BY signal line. Further, the input signal and the output signal of the device are not limited to only the component color television signals Y, RY, and BY. For example, it may be a composite color television signal, in which case a color decoder is added to the input side of the device and a color encoder is added to the output side. Since the composite color television signal output from the color encoder includes an inter-frame difference signal as color signal information, this signal can be observed on a color monitor for the composite signal.
[0028]
Note that the present invention is not limited to the specific embodiment described above, but is applicable to any type of video signal processing device that uses an inter-frame difference of a video signal composed of a luminance signal and a color difference signal.
[0029]
【The invention's effect】
As described above in detail, according to the present invention, an inter-frame difference signal of a luminance signal is obtained, the inter-frame difference output signal is interrupted by a chrominance signal output line, output to a chrominance signal output terminal, This can be displayed visually on a color monitor connected to the side. As described above, according to the present invention, it is easy to display the inter-frame difference amount which could not be confirmed almost in real time on a color monitor as color signal information. Further, in the configuration in which the difference signal output and the color difference signal of the device can be switched, the display of a normal color image can be switched as desired, and the inter-frame difference amount can be displayed on a color monitor as color signal information. .
[0030]
According to the present invention, the magnitude of the difference amount between frames in the details of an image, the distribution on the image, the change due to the movement of the image, and the like are displayed as changes in the color signal information on the color monitor, and this is visually grasped in real time. Can be evaluated. Therefore, it is useful, for example, in hardware debugging of a high-efficiency coding apparatus using an inter-frame difference.
[Brief description of the drawings]
FIG. 1 is a functional block diagram showing an embodiment of a video signal processing device for forming an inter-frame difference display signal according to the present invention.
FIG. 2 is a functional block diagram similar to FIG. 1, showing another embodiment of the video signal processing device according to the present invention.
[Explanation of symbols]
1 Input terminal for luminance signal Y 2 Input terminal for color difference signal RY 3 Input terminal for color difference signal BY 4 Frame memory 5 Interframe difference circuit 6 Interframe signal processing circuit for luminance signal Y 7 Color difference signal RY Inter-frame signal processing circuit 8 Inter-frame signal processing circuit 9, 9a for color difference signal BY Switching circuit 10 Inter-frame difference output signal

Claims (8)

A video signal processing device for forming an inter-frame difference display signal representing a difference between two frames of an input video signal including a luminance signal and a color difference signal, the device comprising:
Difference detection means for obtaining a difference signal between two frames of the luminance signal;
A difference signal inserting means for interrupting the obtained difference signal into an output line of the color difference signal and outputting the signal to a first output terminal. 2. The apparatus according to claim 1, wherein the difference signal inserting means includes a switching means for alternately setting a first and a second connection state, and wherein the switching means is configured to switch the color difference signal in the first connection state. was connected to the first output terminal, the second connection state, the video signal processing apparatus characterized by connecting a pre-Symbol difference component signal to the first output terminal. The device of claim 1, wherein the device further comprises:
First inter-frame signal processing means for performing signal processing over two frames of the luminance signal and outputting the signal-processed luminance signal to a second output terminal;
Second inter-frame signal processing means for performing signal processing over two frames of the color difference signal,
The difference signal inserting means includes a switching means for selectively setting the first and second connection states, and the switching means, in the first connection state, outputs an output of the second inter-frame signal processing means. connected to the first output terminal, the second connection state, the video signal processing apparatus characterized by connecting a pre-Symbol difference component signal to the first output terminal. 3. The apparatus according to claim 2, wherein the color difference signal includes a first color difference signal, and wherein the switching means connects the first color difference signal to a first output terminal in a first connection state; in the connected state, the video signal processing apparatus characterized by connecting a pre-Symbol difference component signal in place of the first color difference signal to a first output terminal. 5. The apparatus according to claim 4, wherein the color difference signal includes a second color difference signal, and the switching means substitutes for the second color difference signal from the second inter-frame signal processing means in the second connection state. A video signal processing device for connecting a reference potential to a first output terminal. The apparatus according to claim 2, said apparatus comprising a video signal processing apparatus characterized by a Brightness signal of the input picture signal by one frame period delay, including a delay means for providing said difference detecting means. A method of processing a video signal for forming an inter-frame difference display signal representing a difference between two frames of an input video signal including a luminance signal and a color difference signal, the method comprising:
Obtaining a difference signal between two frames of the luminance signal;
Interrupting the obtained difference signal into an output line of the color difference signal and outputting the signal. The method of processing a video signal forming an inter-frame difference display signal. The method according to claim 7, further comprising the step of visually displaying a signal obtained by interrupting the difference signal on an output line of the color difference signal as color signal information on a color image display device. Video signal processing method.

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