JP3804155B2 - Image detection apparatus and image detection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image detection apparatus and an image detection method used when generating an intermittent image from a moving image.
[0002]
[Prior art]
When you want to search by playing back video signals at high speed, or when you want to play back video signals with frame dropping and record or transmit them to a recording medium, you can play and display images at regular time intervals. There is known a method for generating an intermittent image for the purpose.
[0003]
[Problems to be solved by the invention]
However, when generating an intermittent image in this way, an appropriate screen is not necessarily selected. For this reason, it may be difficult to grasp the contents of the moving image by making the moving image an intermittent image.
[0004]
There are also editing equipment that detects the scene change position of the recorded video and divides the video signal into meaningful scenes according to the cut points and edits them. It is difficult to detect a screen that is not a cut point or the like when the change in the amount of light is small or the change in the feature amount such as light is severe.
[0005]
The present invention has been made in view of such circumstances, and when intermittent frames are generated by dropping frames from moving images or when high-speed playback is performed, intermittent images and high-speed playback that make it easy to grasp the contents An object of the present invention is to provide an image detection apparatus and an image detection method for detecting an image.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, an image detection apparatus according to the present invention includes a first screen that is a first screen in a moving image and a second screen immediately before the first screen. A first change amount detecting means for detecting a change amount; a second change amount detecting means for detecting a second change amount between the first screen and the previously detected detection screen; Comparing the amount of change with a first threshold, detecting the first screen if the first amount of change is greater than the first threshold, comparing the second amount of change with a second threshold, When the second change amount is larger than the second threshold value, the first change amount is further compared with the first threshold value. When the first change amount is smaller than the first threshold value, the first change amount is compared with the first threshold value. Screen detecting means for detecting the first screen, and output means for outputting the first screen detected by the screen detecting means as a detection screen. The features.
[0007]
In this image detection apparatus, the screen detection means compares the first change amount with the second threshold value immediately before the first screen in the moving image detected by the first change amount detection means with the first threshold value. When the first change amount is larger than the first threshold, the first screen is detected, so that the output means outputs an intermittent image corresponding to the content of the moving image. The second change amount between the first screen detected by the change amount detecting means and the previously detected detection screen is compared with a second threshold value, and the second change amount is greater than the second threshold value. When the change is larger, the first change amount is further compared with the first threshold value. When the first change amount is smaller than the first threshold value, the first screen is detected and the change is converged. The screen is detected, and the output means outputs an intermittent image.
[0012]
Further, in the image detection apparatus according to the present invention, when the second change amount is smaller than the second threshold value, the screen detection unit reduces the second threshold value by a predetermined amount, and the second change amount is equal to the second change amount. When it is determined twice consecutively that it is greater than the second threshold, the first change amount is further compared with the first threshold value. When the first change amount is greater than the first threshold value, the first change amount is compared with the first threshold value. The threshold value is increased by a predetermined amount, and when the first change amount is smaller than the first threshold value, the first screen is detected and the second threshold value is increased by a predetermined amount.
[0013]
In this image detection apparatus, the screen detection means detects the screen by changing the first and second thresholds for comparing the amount of change, and the output means outputs an intermittent image with an average intermittent interval.
[0014]
In order to solve the above-described problem, an image detection method according to the present invention includes a first screen, which is one screen in a moving image, and a second screen immediately before the first screen. Detect the amount of change in 1 A second change amount between the first screen and the previously detected detection screen is detected; The second change amount is compared with a second threshold value. If the second change amount is larger than the second threshold value, the first change amount is further compared with the first threshold value. When the amount of change in 1 is smaller than the first threshold, the first screen is detected, and the detected first screen is output as a detection screen.
[0015]
In this image detection method, the amount of change in the moving image is compared with a first threshold value to detect the screen, and an intermittent image corresponding to the content of the moving image is output.
[0020]
Furthermore, in the image detection method according to the present invention, when the second change amount is smaller than the second threshold value, the second threshold value is decreased by a predetermined amount, and the second change amount is larger than the second threshold value. If the first change amount is further compared with the first threshold value, and if the first change amount is greater than the first threshold value, the first threshold value is increased by a predetermined amount. When the first change amount is smaller than the first threshold value, the first screen is detected and the second threshold value is increased by a predetermined amount.
[0021]
In this image detection method, the screen is detected by changing the first and second thresholds for comparing the amount of change, and an intermittent image with an average intermittent interval is output.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an image detection apparatus according to a first embodiment of the present invention will be described with reference to the drawings.
[0023]
FIG. 1 is a block diagram of an image detection apparatus 1 according to the first embodiment of the present invention. The image detection device 1 calculates an amount of change from an input signal processing circuit 2 to which a video signal is input, a first image memory 3, a second image memory 4, and images stored in the image memories 3 and 4. A change amount detection circuit 5 for detecting, and a representative screen detection control circuit 6 for controlling the image memories 3 and 4 and the change amount detection circuit 5 to output intermittent images are provided.
[0024]
The image detection apparatus 1 having such a configuration detects a representative screen in order to generate an intermittent image from a video signal that is an input moving image.
[0025]
The video signal input to the image detection apparatus 1 is a video signal of a moving image, for example, a video signal recorded on a recording medium or a transmitted video signal. This video signal is supplied to the input signal processing circuit 2.
[0026]
The input signal processing circuit 2 separates an input video signal into a process for converting to an appropriate signal level, an error correction process, a corresponding decoding process when image compression is performed, and a luminance signal and a color signal. Perform processing. That is, the input signal processing circuit 2 performs processing for converting the image data into signals suitable for storing the image data in the first and second image memories 3 and 4.
[0027]
The video signal processed by the input signal processing circuit 2 is supplied to the first image memory 3 and the second image memory 4 in frame units, that is, in screen units. Further, the input signal processing circuit 2 separates the synchronization signal from the video signal and supplies the synchronization signal to the representative screen detection control circuit 6.
[0028]
The first image memory 3 stores image data of the video signal supplied from the input signal processing circuit 2 in units of screens. Similarly, the second image memory 4 also stores the video signal supplied from the input signal processing circuit 2 as image data for each screen.
[0029]
The first image memory 3 and the second image memory 4 have the same configuration, but store different image data. The screen stored in the second image memory 4 is always a screen one screen before in time from the screen stored in the first image memory 3. That is, the screens stored in the first image memory 3 and the second image memory 4 are continuous screens in time series. Note that the temporally previous screen may be alternately stored in the first and second image memories 3 and 4.
[0030]
The change amount detection circuit 5 detects a change amount between temporally continuous screens stored in the first image memory 3 and the second image memory 4. That is, the amount of change is obtained by calculating the difference between the image data stored in the image memories 3 and 4. Further, the amount of change may be obtained by obtaining a motion vector between screens.
[0031]
The representative screen detection control circuit 6 detects a representative screen constituting an intermittent image based on the change amount detected by the change amount detection circuit 5. Further, based on the synchronization signal detected by the input signal processing circuit 2, the timing of writing and reading the image data to the first and second image memories 3 and 4 is also controlled. That is, the representative screen detection control circuit 6 sequentially writes temporally continuous screens constituting a moving image in the image memories 3 and 4 and repeats this process.
[0032]
The representative screen detection control circuit 6 performs a representative screen detection process by comparing the change amount of the image data written in each of the image memories 3 and 4 with a threshold value. Then, the representative screen detection control circuit 6 dynamically changes the threshold value and performs a process of detecting an average screen as the representative screen.
[0033]
The control contents of the representative screen detection control circuit 6 will be described based on the flowchart shown in FIG.
[0034]
When the video signal is input, the representative screen detection control circuit 6 starts processing from the following step S1.
[0035]
In step S1, the threshold is initialized. This threshold value is a value for comparison with the amount of change between the screens stored in the first image memory 3 and the second image memory 4 detected by the change amount detection circuit 5. This threshold value is set according to additional information of an input video signal, external input, intermittent intervals of output intermittent images, and the like.
[0036]
When the initialization of the threshold value is finished in step S1, in step S2, the change amount detection circuit 5 calculates the change amount of the screen stored in the first and second image memories 3 and 4, and acquires this change amount. In this calculation, the absolute value is obtained by subtracting each pixel as a change amount.
[0037]
When this amount of change is acquired, in step S3, this amount of change is compared with a threshold value. If it is determined that the amount of change is not greater than the threshold, the process proceeds to step S4. If it is determined that the amount of change is greater than the threshold, the process proceeds to step S5.
[0038]
In step S7, a subtraction value that is a predetermined value is subtracted from the threshold value. When the threshold value is decreased by a certain amount in step S4, the screen stored in the first and second image memories 3 and 4 is updated to the next screen, and the processing from step S2 is repeated.
[0039]
In step S5, the screen stored in the first image memory 3 is detected as a representative screen. In step S6, the detected representative screen is output.
In step S7, an addition value which is a predetermined value is added to the threshold value. When the threshold value is increased by a certain amount in step S4, the screen stored in the first and second image memories 3 and 4 is updated to the next screen, and the processing from step S2 is repeated.
[0040]
Here, the relationship between the subtraction value that is a constant used to subtract a certain amount from the threshold value in step S4 and the addition value that is a constant used to add a certain amount from the threshold value in step S7 will be described. The threshold value is a value for comparison with the amount of change of each temporally continuous screen constituting the moving image as described above. The representative screen detection control circuit 6 compares the amount of change with a threshold value, and changes the threshold value according to the comparison result. In other words, the variable amount of the threshold is determined by the addition value that is added when the representative screen is detected and the subtraction value that is subtracted when the representative screen is not detected. The detected amount of the representative screen for the input moving image is determined by the value of the addition value and the subtraction value. For example, if the ratio between the addition value and the subtraction value is 1: 100, one representative screen is detected for 100 input moving images. In addition, if the absolute value of the addition value and the subtraction value, which are variable amounts of the threshold value, increases, the detection sensitivity increases, and the representative screen can be detected on average. Furthermore, if the variable amount is small, the detection of the representative screen varies according to the difference detection amount.
[0041]
As described above, in the image detection apparatus 1 according to the first embodiment, when generating an intermittent image from a moving image, the representative screen is detected according to the amount of change between the screens constituting the moving image. This makes it possible to generate an intermittent image that is easy to grasp the contents. Moreover, since the threshold value used when comparing the amount of change is varied, an intermittent image generated at a constant average rate can be obtained regardless of the characteristics of the moving image. Therefore, the capacity can be easily managed when the generated intermittent image is recorded or transmitted.
[0042]
Furthermore, the image detection apparatus 1 according to the first embodiment can be used for high-speed playback of moving images, and is also used for detecting a typical screen when searching for moving images. be able to.
[0043]
Next, an image detection apparatus according to a second embodiment of the present invention will be described with reference to the drawings. In the description of the image detection apparatus according to the second embodiment, the same reference numerals are given to the components having the same functions as those of the image detection apparatus 1 according to the first embodiment described above, and the details thereof. The detailed explanation is omitted. Hereinafter, the same applies to the third embodiment.
[0044]
As shown in FIG. 3, the image detection apparatus 10 according to the second embodiment includes an input signal processing circuit 2 to which a video signal is input, a first image memory 3, a second image memory 4, A change amount detection circuit 5 that detects a change amount stored in each image memory 3, 4, a representative screen detection control circuit 6 that outputs an intermittent image by controlling these components, and a first image memory 3 And an average value calculation circuit 7 for converting the average value of the brightness of the screen.
[0045]
In the image detection apparatus 10 according to the second embodiment, a representative screen is detected from a video signal that is a moving image inputted by correcting not only the amount of change between screens but also the change in screen brightness. An intermittent image is generated.
[0046]
The average value calculation circuit 7 calculates the average value of the luminance of the image data in the image memory 3 before the change amount detection circuit 5 detects the change amount between images.
[0047]
The change amount detection circuit 5 detects the change amount using the average value of the image data calculated by the average value calculation circuit 7. The amount of change is detected using this average value because when the luminance signal is used as data, the value of the pixel data on a bright and bright screen is high and the difference becomes large. is there. Therefore, by dividing the change amount by the average value of luminance, it is possible to detect a representative screen that is not affected by brightness. Further, the average value of the luminance is supplied to the representative screen detection control circuit 6, and the brightness value is changed by changing the value of the addition value and the subtraction value without changing the ratio of the addition value and the subtraction value for changing the threshold value. It is also possible to detect a representative screen that is not affected.
[0048]
In addition, when calculating this average value, the image data in the image memory is divided into a plurality of regions and calculated for each region, so that even for images whose brightness and movement are partially biased in the plane. Yes. When the area is divided, the detection amount can be weighted by not dividing the screen equally, for example, by reducing the area of the central portion of the screen. It is also possible to give a clear weight by setting a value for each divided area and calculating a coefficient of an average value.
[0049]
As described above, in the image detection apparatus 10 according to the second embodiment, when generating an intermittent image from a moving image, the representative screen is detected according to the amount of change between the screens constituting the moving image. Thus, it is possible to generate an intermittent image that is easy to grasp the contents. Moreover, since the threshold value used when comparing the amount of change is varied, an intermittent image generated at a constant average rate can be obtained regardless of the characteristics of the moving image. Therefore, the capacity can be easily managed when the generated intermittent image is recorded or transmitted.
[0050]
In the second embodiment, not only the amount of change between screens but also the change in screen brightness is corrected and a representative screen is detected from a video signal that is an input moving image to generate an intermittent image. As a result, it is possible to reduce the fluctuation of the detection result of the intermittent image due to the change in the brightness of the image.
[0051]
Next, an image detection apparatus according to a third embodiment of the present invention will be described with reference to the drawings.
[0052]
FIG. 4 is a block configuration diagram of the image detection apparatus 20 according to the third embodiment. The image detection device 20 includes an input signal processing circuit 2 to which a video signal is input, a first image memory 3, a second image memory 4, a third image memory 8, and first and second images. A first change amount detection circuit 5 that detects a change amount from the screen stored in the memories 3 and 4, and a second change amount detection circuit 5 that detects the change amount from the screens stored in the first and third image memories 3 and 8. A change amount detection circuit 9 and a representative screen detection control circuit 11 that controls these components and outputs intermittent images are provided.
[0053]
The representative screen detection control circuit 11 detects a representative screen constituting an intermittent image based on the change amount detected by the first change amount detection means and the change amount detected by the second change amount detection circuit 9. In addition, based on the synchronization signal detected by the input signal processing circuit 2, the timing of writing and reading the image to the first, second, and third image memories 3, 4, and 8 is also controlled.
[0054]
The representative screen detection control circuit 11 compares the amount of change of the image data written in each of the image memories 3, 4, and 8 with the threshold value, and performs a representative screen detection process. Then, the representative screen detection control circuit 11 dynamically changes the threshold value and performs a process of detecting an average screen as the representative screen.
[0055]
The third image memory 8 stores a representative screen detected by the representative screen detection control circuit 11. The representative screen detection control circuit 11 detects the representative screen and generates an intermittent image. When the representative screen is detected, the representative screen detection control circuit 11 outputs the intermittent image and stores the representative screen in the third image memory 8. Note that the third image memory 8 always stores only one representative screen. When the next representative screen is stored in the previously stored representative screen, the previous representative screen is overwritten. .
[0056]
The second change amount detection circuit 9 detects the change amount between the screen stored in the first image memory 2 and the representative screen stored in the third image memory 8.
[0057]
The control contents of the representative screen detection control circuit 11 will be described based on the flowchart shown in FIG.
[0058]
First, each variable used for control in the flowchart shown in FIG. 5 will be described.
[0059]
For the control of the representative screen detection control circuit 11, the first threshold value and the second threshold value are used. The first threshold value is a value for comparison with the change amount between images detected by the first change amount detection circuit 5, and the second threshold value is detected by the second change amount detection circuit 9. This is a value for comparing the amount of change between the screens stored in the first image memory 3 and the third image memory 8.
[0060]
In the control of the representative screen detection control circuit 11, a subtraction value that is a constant used to subtract a certain amount from the second threshold value and an addition value that is a constant used to add the certain amount from the threshold value are used. ing. The relationship between the subtraction value and the addition value is the same as that in the first embodiment described above.
[0061]
In the control of the representative screen detection control circuit 11, a continuous detection flag is used. This continuous detection flag does not immediately capture this screen as a detection result even when a screen exceeding the threshold is detected by the difference detection between the screens by the second change amount detection circuit 9, and continuously exceeds the threshold. Used to detect the screen when a difference is detected.
[0062]
The control of the representative screen detection control circuit 11 uses a detection weight. In the representative screen detection control circuit 11, once the representative screen is detected, a second change amount detection circuit 9 that compares the change amounts of the screens stored in the first image memory 3 and the third image memory 8 is continuously provided. Even if the screen is detected, processing is performed so that the capture is performed after the amount of change in the first image memory 3 and the second image memory 4 that are temporally continuous decreases. However, in the case of a moving image with continuous intense motion, the first threshold value does not decrease, so that a representative screen detection output does not occur. For this reason, the first threshold value is manipulated by this detection weight so as to correspond to a moving image with intense motion.
[0063]
In step S11, the representative screen detection control circuit 11 initializes set values of variables such as threshold values. This threshold value may be set according to the additional information of the input moving image, the external input, the intermittent interval of the intermittent image to be output, and the like. Further, the amount of change in the threshold value may be set similarly.
[0064]
When the initialization is completed in step S11, in step S12, the second change amount detection circuit 9 is caused to calculate the amount of change of the screen stored in the first and third image memories 3 and 8, and the second change amount is calculated. get. In this calculation, the absolute value is obtained by subtracting each pixel as a change amount. The screen stored in the third image memory 8 stores the representative screen detected earlier. If the detected representative screen does not exist first, for example, all pixel values may be calculated as 0.
[0065]
When the second change amount is acquired, in step S13, the second change amount is compared with the second threshold value. If it is determined that the second change amount is not greater than the second threshold value, the process proceeds to step S14. If it is determined that the first change amount is greater than the first threshold value, the process proceeds to step S18.
[0066]
If it is determined that the first change amount is not larger than the first threshold value, the continuous detection flag is cleared in step S14, the detection weight is cleared in subsequent step S15, and a predetermined value is determined from the second threshold value in subsequent step S16. Subtract the first subtraction value that is the value. In step S17, the screen stored in the first and second image memories 3 and 4 is updated to the next screen, and the processing from step S12 is repeated. If it is determined in step S13 that the first change amount is larger than the first threshold value, it is determined in step S18 whether or not the continuous detection flag is set. If it is determined that the continuous detection flag is not set, the continuous detection flag is set in step S19, and the process proceeds to step S15, step S16, and step S17 described above, and the processing from step S12 is repeated.
[0067]
If it is determined in step S18 that the continuous detection flag is set, the change amount of the screen stored in the first and second image memories 3 and 4 is stored in the first change amount detection circuit 5 in step S20. The first change amount is obtained by calculation. In this calculation, the absolute value is obtained by subtracting each pixel as a change amount.
[0068]
When the first change amount is acquired, in step S21, the first change amount is compared with the first threshold value. The first threshold value is a comparison value for determining whether or not the first change amount is smaller than the second change amount, and is a value smaller than the second threshold value. The first threshold value is preferably a value linked to the second threshold value. For example, when the second threshold value is K, the first threshold value is preferably 1 / K.
[0069]
When it is determined that the first change amount is not smaller than the first threshold value, the motion of the moving image has not converged. Therefore, the detection weight is added to the first threshold value in step S22 on the assumption that the movement has not decreased. This detection weight is to add a predetermined amount of value to the first threshold, and even if the moving image does not converge forever, an appropriate screen can be obtained by adding this detection weight to the first threshold. The representative screen is detected at intervals of. When the detection weight is added to the first threshold value in step S22, the process proceeds to step S16 and step S17 described above and the processing from step S12 is repeated.
[0070]
When it is determined that the first change amount is smaller than the first threshold value, the process proceeds to step S23. In step S23, the screen stored in the first image memory 3 is detected as a representative screen, and the representative screen is output. In step S23, the detected representative screen is stored in the third image memory 8.
[0071]
When the representative screen is detected in step S23, the continuous detection flag is cleared in step S24, and an added value, which is a predetermined value, is added to the second threshold value in step S25. Next, in step S17, the screen stored in the first and second image memories 3 and 4 is updated to the next screen, and the processing from step S12 is repeated.
[0072]
The intermittent image output from the image detection device 20 will be described below.
[0073]
In the first example, as shown in FIG. 6 (a), the A scene and the B scene are included in the image detection device 20 at the cut point t. ₁ An example is shown in which a moving image to be switched at is input.
[0074]
In this case, as shown in FIG. 6B, the third image memory 8 stores X in the figure. ₁ The data of screen A is written. X in the figure input to the first image memory 3 at this time ₂ When the screen is switched to B, a difference occurs with the image data in the third image memory 8 and thus becomes larger than the second threshold value. However, since a difference also occurs in the next second image memory 4, the representative screen is not detected. Next, X in the figure is stored in the first image memory 3. _Three When the screen B is written, a difference from the screen A of the third image memory 8 occurs, and X in the figure of the second image memory 4 appears. ₂ Since no difference occurs from the screen B, the representative screen is detected because the difference is smaller than the first threshold. Therefore, detection is performed after the screen converges one frame after switching from scene A to scene B.
[0075]
In the second example, as shown in FIG. 7A, an example in which a moving image including a screen B that is a flash light such as a flash light or a lightning is input to the image detection device 20 between the screen A is shown. Show.
[0076]
In this case, as shown in FIG. 7B, the third image memory 8 contains Y in the figure. ₁ Screen A is written on the screen. Y in the figure ₂ When the screen B is written in the first image memory 3, the difference is generated in both the third image memory 8 and the second image memory 4, so that the representative screen is not detected. In the following figure, Y _Three Similarly, when the screen A is input to the first image memory 3, no difference is generated, so that the representative screen is not detected. That is, no detection is made in the flash portion.
[0077]
In the third example, as shown in FIG. 8A, a moving image in which the screen such as fade, wipe, pan, etc. in which the screen for special effects gradually changes is constantly changed is input to this image detection device 20. An example is shown.
[0078]
In this case, as shown in FIG. 8B, the third image memory 8 includes Z ₁ Screen A is written. Next, when the screen B is input to the first image memory 3, a difference occurs in both the third image memory 8 and the second image memory 4. Next screen C, screen D, screen E, Z in the figure ₂ The screen F is not detected because a difference occurs. Z in the following figure _Three On the screen F, no difference from the second image memory 4 occurs, and this screen F becomes the representative screen. Therefore, detection is performed when the desired moving image is stationary.
[0079]
As described above, in the image detection apparatus 20 according to the third embodiment, when generating an intermittent image from a moving image, the representative screen is detected according to the amount of change between the screens constituting the moving image. This makes it possible to generate an intermittent image that is easy to grasp the contents. Moreover, since the threshold value used when comparing the amount of change is varied, an intermittent image generated at a constant average rate can be obtained regardless of the characteristics of the moving image. Therefore, the capacity can be easily managed when the generated intermittent image is recorded or transmitted.
[0080]
Further, in the image detection apparatus 20 according to the third embodiment, even if the amount of change from the previously detected representative screen is large, detection processing is performed after the amount of change has converged. When detecting a representative screen from a signal and generating an intermittent image, it is possible to detect a change point of a scene by detecting a change between the screens, or to prevent detection of an unnecessary screen such as a false detection. For example, it is possible to prevent detection of special screens such as surface switching and flashing due to special effects.
[0081]
In the image detection apparatus 20 according to the third embodiment, the case where an image for one frame is removed using the first image memory 3 and the second image memory 4 is shown. By using a plurality of memories in addition to the memory 4, unnecessary images for a plurality of frames can be removed, and images for a plurality of frames can be obtained by shifting the frames stored in the second image memory 4 in time. Can be removed.
[0082]
Next, a video signal recording / reproducing apparatus according to a fourth embodiment to which the present invention is applied will be described. In the video signal recording / reproducing apparatus according to the fourth embodiment, the first image detecting apparatus 1 described above is applied to a video / audio signal recording / reproducing apparatus.
[0083]
As shown in FIG. 9, the video / audio signal recording / reproducing apparatus 50 includes an input signal processing unit 51 that performs input processing of an input video signal and audio signal, and a video signal and a signal that are processed by the input signal processing unit 51. A video / audio signal processing unit 52 that reproduces an audio signal, an image detection processing unit 55 that generates an intermittent image from the video signal reproduced by the video / audio signal processing unit 52, and an interpolation to the video signal reproduced by the video / audio signal processing unit 52 An intermittent image processing unit 53 for processing, an output signal processing unit 54 for outputting a video signal interpolated by the intermittent image processing unit 53, and a recording / reproducing signal for performing signal processing such as modulation / demodulation to record / reproduce the video signal A processing unit 56, a recording / reproducing unit 57 for recording / reproducing the video / audio signal on the recording medium 59, an intermittent image processing unit 53, a recording / reproducing signal processing unit 56, etc. And a troll section 58.
[0084]
The input video / audio signal is, for example, a video signal and an audio signal of a moving image, and is subjected to processing such as signal level conversion by the input signal processing unit 51 and is supplied to the video / audio signal processing unit 52.
[0085]
The video / audio signal processing unit 52 performs processing of converting the video signal and audio signal processed by the input signal processing unit 51 into signals suitable for subsequent processing. The signal reproduced from the recording medium 59 from the recording / reproducing signal processing unit 56 is similarly processed. For example, when error correction processing or image compression processing is performed, corresponding decoding processing, processing for separating a luminance signal and a color signal, and the like are performed. The video / audio signal processing unit 52 supplies the output video signal to the image detection processing unit 55, the intermittent image processing unit 53, and the recording / reproduction signal processing unit 56.
[0086]
The image detection processing unit 55 is, for example, the image detection apparatus 1 according to the first embodiment described above. The image detection processing unit 55 detects the representative screen from the moving image and generates an intermittent image. This intermittent image is supplied to the recording / reproducing signal processing unit 56.
[0087]
The recording / playback signal processing unit 56 performs data conversion processing for supplying a signal played back from the recording medium 59 via the recording / playback unit 57 to the video / audio signal processing unit 52 based on the control of the system control unit 58. . Further, based on the control of the system control unit 58, data conversion processing for recording the signal supplied from the video / audio signal processing unit 52 on the recording medium 59 is performed.
[0088]
The recording / reproducing unit 57 records intermittent video signals and audio signals on the recording medium 59 or reproduces intermittent video signals and audio signals recorded on the recording medium 59.
[0089]
The intermittent image processing unit 53 performs interpolation processing on the intermittent image reproduced from the recording medium 59. Here, the interpolation processing is, for example, processing for performing up-conversion of a moving image by outputting the same image multiple times using an image memory when outputting a still image.
The output signal processing unit 54 performs digital / analog conversion processing, amplification processing, and the like of the video signal so that the video signal can be reproduced by the monitor. By supplying the output from the output signal processing unit 54 to a monitor or the like, the viewer can view the video and audio subjected to the interpolation processing.
[0090]
As described above, the video / audio signal recording / reproducing apparatus 50 includes the image detection processing unit 55, and can generate and record an intermittent image from the input moving image. The image detection processing unit 55 may be not only the image detection device 1 of the first embodiment described above but also the image detection devices 10 and 20 of the second and third embodiments.
[0091]
In the video signal storage / reproduction device 50, the video signal is recorded as a moving image, and a detection result for performing intermittent reproduction is recorded separately, thereby generating an intermittent image during reproduction. Can do. For this reason, the video / audio signal recording / reproducing apparatus 50 reproduces the video signal recorded on the recording medium 59, for example, as a digest version, and is useful for grasping the outline of the video signal and the like for editing work.
[0092]
【The invention's effect】
In the image detection apparatus according to the present invention, the first change amount from the second screen immediately before the first screen in the moving image detected by the first change amount detection unit is detected by the screen detection unit. By detecting the first screen when the first change amount is larger than the first threshold value as compared with the threshold value, the output unit outputs an intermittent image corresponding to the content of the moving image, An intermittent image in which the contents can be easily grasped can be generated, high-speed reproduction can be performed, and the first screen detected by the second change amount detecting means and the first detected screen are detected. 2 is compared with the second threshold, and if the second change is greater than the second threshold, the first change is further compared with the first threshold. When the amount of change is smaller than the first threshold, the effective screen is detected by detecting the first screen. Can make the detection, it is possible to generate an intermittent image without being influenced by the characteristics of the image. Furthermore, the capacity can be easily managed when the generated intermittent image is recorded and transmitted.
[0096]
In the image detection method according to the present invention, a first change amount between a first screen which is one screen in a moving image and a second screen immediately before the first screen is detected, A second change amount between the first screen and the previously detected detection screen is detected; The second change amount is compared with a second threshold value. If the second change amount is larger than the second threshold value, the first change amount is further compared with the first threshold value. When the change amount of 1 is smaller than the first threshold, the first screen is detected, and by outputting an intermittent image corresponding to the content of the moving image, only an effective screen can be detected. An intermittent image can be generated without being influenced by the characteristics of Furthermore, the capacity can be easily managed when the generated intermittent image is recorded and transmitted.
[Brief description of the drawings]
FIG. 1 is a block diagram of an image detection apparatus to which the present invention is applied.
FIG. 2 is a flowchart showing control contents of a representative screen detection control circuit of the image detection apparatus to which the present invention is applied.
FIG. 3 is a block diagram of an image detection apparatus to which the present invention is applied.
FIG. 4 is a block diagram of an image detection apparatus to which the present invention is applied.
FIG. 5 is a flowchart showing control contents of a representative screen detection control circuit of the image detection apparatus to which the present invention is applied.
FIG. 6 is an explanatory diagram of an intermittent image output from an image detection apparatus to which the present invention is applied.
FIG. 7 is an explanatory diagram of an intermittent image output from an image detection apparatus to which the present invention is applied.
FIG. 8 is an explanatory diagram of an intermittent image output from an image detection apparatus to which the present invention is applied.
FIG. 9 is a block diagram of a video / audio signal recording / reproducing apparatus to which the present invention is applied;
[Explanation of symbols]
1, 10, 20 Image detection device, 2 Input signal processing circuit, 3 First image memory, 4 Second image memory, 5 Change amount detection circuit, 6, 11 Representative screen detection control circuit, 7 Average value calculation circuit, 8 Third image memory, 9 Second change amount detection circuit

Claims (10)

First change amount detection means for detecting a first change amount between a first screen that is one screen in a moving image and a second screen immediately before the first screen;
A second change amount detecting means for detecting a second change amount between the first screen and the previously detected detection screen;
The second change amount is compared with a second threshold value, and if the second change amount is larger than the second threshold value, the first change amount is further compared with the first threshold value. Screen detecting means for detecting the first screen when the amount of change of 1 is smaller than the first threshold;
An image detection apparatus comprising: output means for outputting the first screen detected by the screen detection means as a detection screen.   When the second change amount is smaller than the second threshold value, the screen detection means reduces the second threshold value by a predetermined amount, and when the second change amount is continuously larger than the second threshold value. Further compares the first change amount with a first threshold value. If the first change amount is larger than the first threshold value, the first threshold value is increased by a predetermined amount, and the first change amount is set to the first threshold value. The image detection apparatus according to claim 1, wherein when the threshold value is smaller than the threshold value, the first screen is detected and the second threshold value is increased by a predetermined amount.   The image detection apparatus according to claim 2, wherein the first threshold value and the second threshold value are values interlocked with each other that satisfy a condition of first threshold value <second threshold value.   The image detection apparatus according to claim 1, further comprising recording means for recording the detection screen on a recording medium.   The image detection apparatus according to claim 1, further comprising transmission means for transmitting the detected screen. Detecting a first change amount between a first screen that is one screen in a moving image and a second screen immediately before the first screen;
A second change amount between the first screen and the previously detected detection screen is detected;
The second change amount is compared with a second threshold value, and if the second change amount is larger than the second threshold value, the first change amount is further compared with the first threshold value. When the amount of change of 1 is smaller than the first threshold, the first screen is detected,
An image detection method, comprising: outputting a detected first screen as a detection screen.   When the second change amount is smaller than the second threshold value, the second threshold value is decreased by a predetermined amount, and when the second change amount is continuously larger than the second threshold value, the first threshold value is further reduced. The amount of change is compared with a first threshold. When the first amount of change is greater than the first threshold, the first threshold is increased by a predetermined amount, and when the amount of first change is less than the first threshold, The image detection method according to claim 6, wherein one image is detected and the second threshold value is increased by a predetermined amount.   8. The image detection method according to claim 7, wherein the first threshold value and the second threshold value are values interlocked with each other that satisfy the condition of the first threshold value <the second threshold value.   The image detection method according to claim 6, wherein the detection screen is recorded on a recording medium.   The image detection method according to claim 6, wherein the detection screen is transmitted.

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