JPH10233994A - Specific area extract device and its method, specific area information recorder and its method, and specific area information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extract accurately a specific area such as all telop signals under every environment. SOLUTION: A uniform recording area detection circuit 3 compares a luminance level of an optional picture element of a video signal in a television signal with a luminance level of surrounding picture elements to detect an area of a nearly uniform luminance level. A high frequency area detection circuit 4 detects a high frequency component in an optional video image plane of the video signal. A constant time no change picture element detection circuit 5 discriminates whether or not the luminance level of the optional picture element is unchanged for more than a prescribed time. An extract circuit 6 extracts a telop signal based on each output of the uniform recording area detection circuit 3, the high frequency area detection circuit 4 and the constant time no change picture element detection circuit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a specific area extracting apparatus and method for extracting a specific area such as a telop in a video signal in a television broadcast, and to record information on the special area together with a video signal on a recording medium. The present invention relates to a specific area information recording device and method, and a specific area information recording medium that records the specific area information together with a video signal.

[0002]

2. Description of the Related Art Generally, a telop is inserted into a television broadcast as a visual effect of a program. In general, the contents considered to be important in a program are displayed in characters or pictures, so that the viewer can further understand the contents of the program. Conventionally, as a method for detecting this telop, first, a method of detecting pixels having a constant luminance continuously in the time direction, second, a method of detecting an area having a higher luminance level than neighboring pixels, and third, There is a method of detecting an edge in a screen and detecting that an edge pattern is continuous with a predetermined area.

[0003]

By the way, the above-mentioned conventional methods are all general, but can detect only a limited number of telops in a limited environment.

In order to be adaptable to all telops in all environments, it is necessary to develop algorithms that can adapt to various environments. Further, even if a telop is detected, there is no means to use it.

The present invention has been made in view of the above circumstances, and has as its object to provide a specific region extracting apparatus and method for accurately extracting a specific region such as all telops in any environment.

Further, the present invention has been made in view of the above circumstances, and provides a specific area information recording apparatus and method capable of allowing a user to accurately and quickly grasp the contents of a video signal recorded on a recording medium. With the goal.

Another object of the present invention is to provide a specific area information recording medium capable of accurately and promptly informing a user of the content of a recorded video signal. .

[0008]

Generally, a telop as the specific area has the following three features.
(1) It is composed of pixels of the same signal level. (2) Since the display is normally performed for 3 to 4 seconds or more, the pixels constituting the telop keep the same signal level for a predetermined time or more.
(3) There is a large difference between the background image and the signal level to make the telop stand out. That is, the telop area is an area having a relatively high spatial frequency in the image plane.

In order to solve the above-mentioned problems, in the specific area extracting apparatus according to the present invention, the uniform level area detecting means compares an arbitrary pixel level of a video signal with a peripheral pixel level and detects the level. An output, an output in which the pixel level unchanged determining means determines whether or not the arbitrary pixel level has been unchanged for a predetermined time or more, and a high frequency area detecting means detects a high frequency component of the frequency in the arbitrary image plane The extracting means extracts the specific area based on the output thus obtained.

Further, the specific area extracting method according to the present invention comprises:
In order to solve the above problem, a substantially uniform level region is detected by comparing an arbitrary pixel level of a video signal with peripheral pixel levels, and it is determined whether or not the arbitrary pixel level remains unchanged for a predetermined time or more. Then, a high frequency range of a frequency component in an arbitrary video plane of the video signal is detected, and a specific region is extracted based on each output.

[0011] Further, if information on the telop is recorded together with the video signal, the user can comprehend the video in which the telop appears, and on the basis of this, it is possible to create an effective program index and understand the program at a quick glance. It becomes possible.

Therefore, a specific area information recording apparatus according to the present invention records specific area information on a specific area included in an input video signal extracted by a specific area extracting means on a recording medium together with the input video signal by a recording means. This allows the user to grasp the content of the video signal.

Further, the specific area information recording method according to the present invention extracts a specific area included in an input video signal, and records specific area information relating to the extracted specific area together with the input video signal on a recording medium. Then, the user is made to grasp the contents of the video signal.

Further, the specific area information recording medium according to the present invention records the specific area information on the specific area included in the video signal together with the video signal, so that the user can grasp the content of the recorded video signal. Let it do.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a specific area extracting apparatus and method, a specific area information recording apparatus and method, and a specific area information recording medium according to the present invention.

First, an embodiment relating to a specific region extracting apparatus and method will be described. This embodiment is a telop extracting apparatus as shown in FIG. 1 for extracting a telop included in a television signal as a specific area.

The telop extracting apparatus 1 compares a luminance level of an arbitrary pixel of a video signal in a television signal with a luminance level of a peripheral pixel and detects a region having a substantially uniform luminance level. A high frequency region detection circuit 4 for detecting a high frequency component of a frequency component in an arbitrary image plane of the image signal; and a fixed time period for determining whether or not the luminance level of the arbitrary pixel remains unchanged for a predetermined time or more. A change pixel detection circuit 5, a uniform recording area detection circuit 3, a high frequency area detection circuit 4, and an extraction circuit 6 for extracting a telop based on each output of the unchanged pixel detection circuit 5 for a fixed time are provided. Here, the uniform recording area detection circuit 3, the high frequency area detection circuit 4, the unchanged pixel detection circuit 5 for a fixed time, and the extraction circuit 6 constitute the telop extraction unit 2.

The telop extracting section 2 uses a uniform luminance area detecting circuit 3, a high frequency area detecting circuit 4, a constant time invariant pixel detecting circuit 5 and an extracting circuit 6 to extract a telop from the video signal passed through the video accumulating section 7. And outputs telop information related to the telop. Here, the video storage unit 7
Are the five frame memories 7 ₁ , 7 ₂ , 7 ₃ , 7 ₄ and 7 ₅
And stores the input video signal at a predetermined cycle.

[0019] where a series of telop extraction processing by the caption extraction unit 2 has been completed for one frame, the video data contained in the frame memory 7 ₁ to frame memory 7 _2,
To the video data frame memory 7 ₃ contained in the frame memory 7 _2, the video data frame memory 7 ₄ contained in the frame memory 7 _3, video data contained in the frame memory _{7. 4} the frame memory 7 ₅ And shift.
That is, 1 process content in the frame memory 7 _{1-7 5} (usually 1
Video data shifted in the time direction by frame time is stored.

The uniform luminance area detection circuit 3 calculates the difference between the luminance level of an arbitrary pixel and the peripheral pixel level in a block consisting of a predetermined number of pixels centered on the arbitrary pixel. An area having a uniform luminance level is detected in accordance with the number of the following arbitrary pixels.

The processing inside the uniform luminance area detecting circuit 3 will be described below with reference to the flowchart shown in FIG. The processing in the uniform luminance area detection circuit 3 is processing performed to detect an area satisfying (1) of the characteristics of the telop, that is, “composed of pixels having the same signal level”.

In step S1, for all pixels in the video screen, the difference in luminance level between an arbitrary pixel of interest and nearby peripheral pixels is calculated for each 3 × 3 block around the target pixel, and the difference is calculated. The number of pixels whose absolute value is equal to or smaller than a predetermined threshold value is counted.

In step S2, step S1
Is compared with a predetermined threshold value α, and if it is not less than α, it means that there are many pixels having similar signal levels to the target pixel in step S3.
It is determined that the target pixel is included in the uniform luminance area. Here, α is, for example, 4.

The high-frequency region detection circuit 4 extracts high-frequency regions in two axial directions of a plurality of orthogonal coordinate systems in a plurality of arbitrary directions on a plane where the video signal is developed, and extracts the high-frequency regions extracted by the plurality of orthogonal coordinate systems. The logical product of the regions is calculated to detect the high frequency component. Specifically, the high-frequency region detection circuit 4 is a process performed to detect a region satisfying the characteristic (3) of the telop, that is, "the telop region is a region having a relatively high spatial frequency". High-frequency components are extracted by applying a high-pass filter in the video space. In the telop extraction device 1, a high-pass filter having two taps is used for simplifying the calculation. For all the pixels in the video screen, if the luminance difference between the target pixel and the adjacent pixels in the vertical and horizontal directions is equal to or greater than a predetermined threshold β, the target pixel is determined to be an edge component (high-frequency component). judge.

The fixed-time unchanged pixel detection circuit 5 detects whether or not the change of the pixel level on the same coordinate of the video signal for 5 frames from the video storage unit 7 has not changed for a predetermined time or more. The processing in the fixed-time unchanged pixel detection circuit 5 will be described below with reference to FIG. The processing in the constant-time unchanged pixel detection circuit 5 satisfies the characteristic (2) of the telop, that is, the area that satisfies the condition that "the pixels forming the telop provide the same signal level for a predetermined time or more". This is a process performed to detect the.

[0026] The predetermined time unchanged pixel detection circuit 5 and have as input the information of the frame memory 7 _{1-7 5,} FIG. 3 (a), (b) , (c), (d) and (e) Like 5
Pixels whose change is equal to or less than a predetermined value for pixels at the same coordinates in a sheet of image are detected. That is, in the five images, pixels at the same coordinates where there is no change in signal level are determined to be pixels that have not changed for a certain period of time, and are detected as pixels that have not changed for a certain period of time. This is performed for pixels at all coordinates. here,
The rectangle shown in FIG. 3 (f) is detected.

The extraction circuit 6 adds a predetermined weight to each output of the uniform luminance area detection circuit 3, the high frequency area detection circuit 4, and the invariable pixel detection circuit 5 for a certain period of time, thereby adding the evaluation value of each pixel. Is calculated, and a telop is extracted based on the evaluation value.

The processing in the extraction circuit 6 will be described below with reference to the flowchart of FIG. 4 and FIGS.

In step S11 of FIG. 4, the output of the uniform luminance area detecting circuit 3, which has been binarized to "0" and "1", the output of the high frequency area detecting circuit 4, and the output of the unchanged pixel detecting circuit 5 for a certain period of time. A value obtained by adding a predetermined weight to the output is calculated as a final evaluation value of each coordinate on the image plane. In the telop extraction device 1, the output of the uniform luminance region detection circuit 3 is weighted by "2", the output of the high-frequency region detection circuit 4 is weighted by "1", and the output of the unchanged pixel detection circuit 5 for a fixed time is weighted. "3" is applied.

[0030] Specific examples of original images are stored in the frame memory ₇₁ in FIG. 5, a specific example of a uniform luminance region detecting circuit 3 outputs the result in FIG. 6, the output of the high frequency region detecting circuit 4 Specific An example is shown in FIG.
8 shows a specific example of the output result, and FIG. 9 shows a specific example of the calculation result of the evaluation value after adding the weighted results to the results of FIGS.

Next, in step S12 of FIG. 4, data on the evaluation value of each pixel is projected and accumulated on two base axes of two orthogonal coordinate systems. The two rectangular coordinate systems include a first rectangular coordinate system based on the horizontal and vertical axes of the image, and a second rectangular coordinate obtained by rotating the first rectangular coordinate system by 45 degrees counterclockwise. System.
FIG. 10 shows a specific example in which the evaluation values shown in FIG. 9 are projected on the first rectangular coordinate system to determine the cumulative frequency, and FIG. 10 shows a specific example in which the cumulative values are calculated by projecting the evaluation values on the second rectangular coordinate system. Figure 11 for an example
Shown in

In the two cumulative degree distributions shown in FIGS. 10 and 11, only values larger than a predetermined threshold value shown by a thick broken line are extracted in step S13 in FIGS. 12 and 13. Then, in step S14,
The common area is extracted in each of FIG. 12 and FIG.

Next, in step S15, a common part is extracted from the regions extracted in the two orthogonal coordinate systems. This is shown in FIG. Then, in step S16, a rectangle circumscribing this area is determined. This is shown in FIG. The area shown in FIG. 14D is determined as the finally extracted telop area.

The telop area information in FIG.
Various forms of output can be considered according to the output destination. Here, appearance position information such as upper left and lower right coordinates of the telop area shown in FIG. 14D is used as the telop area output in step S17.

If the extracted area does not exist, it is determined that no telop has appeared in the screen, and that fact is output. When a telop area cannot be detected in the present embodiment, the upper left horizontal and vertical coordinates and the lower right horizontal and vertical coordinates of the telop area serving as output data are set to 0 and output.

As described above, in the telop extraction apparatus 1, the uniform luminance level area detection circuit 3 compares the output level of the uniform luminance level area detected by comparing an arbitrary pixel level of the video signal with the peripheral pixel level, and outputs the signal for a predetermined time. Unchanged pixel detection circuit 5
Is extracted based on an output that determines whether or not the arbitrary pixel level remains unchanged for a predetermined time or more and an output that the high-frequency area detection circuit 4 detects the high frequency component of the frequency in the arbitrary image plane. Since circuit 6 extracts the telop,
Specific regions such as all telops in any environment can be accurately extracted.

Here, the telop extracting section 2 may be constituted by software in a computer (not shown). In addition, although the luminance signal was used for pixel level comparison,
An RGB signal or a color difference signal may be used.

Next, an embodiment relating to a specific area information recording apparatus and method will be described. In this embodiment,
A telop information recording device 10 as shown in FIG. 15 for recording telop information relating to a specific area such as a telop included in a television signal together with a video signal on a recording medium.

The telop information recording apparatus 10 extracts a telop included in a video signal input, and outputs telop area information relating to the extracted telop. And a recording system controller 12 for recording the image signal together with the video signal on a recording medium 13.

The telop extracting device 11 has the same configuration as the telop extracting device 1 and performs the same operation. Here, the description is omitted.

The recording controller 12 creates the telop area information as write data in a write data buffer in the recording controller 12. Here, 5 bytes (40 bits) of write data are prepared for one frame of the video signal as shown in FIG.
As its contents, an identification signal indicating whether or not there is a telop in the screen is added to the least significant bit (0th bit). If a telop is detected, this bit is set to “1”.
Otherwise, set to "0". From the first bit to the tenth bit of the write data, the horizontal coordinate of the upper left point of the telop area is set. From the 11th bit to the 19th bit, the vertical coordinate of the upper left point of the telop area is set. The horizontal coordinate of the lower right point of the telop area is substituted for the bit, and the vertical coordinate of the right point of the telop area is substituted for the 30th to 38th bits. The 39th bit is a spare area.

The video screen handled by the telop information recording device 10 uses a VGA size (640 × 480). The write data size can be made variable according to the screen size.

In the data buffer (not shown) inside the recording controller 12, the write data created by the above processing is modulated together with the video data into a recording format, and sent to the recording controller circuit 12. The recording controller 12 records the video signal and the write data on the recording medium 13.

Here, a hard disk is used as the recording medium 13, but the same effect can be obtained by substituting a semiconductor memory, optical disk, magnetic disk, magneto-optical disk, magnetic tape, or the like.

As described above, this telop information recording apparatus 1
No. 0 records the telop area information extracted by the telop extraction device 11 on the recording medium 13 together with the input video signal by the recording system controller 12, so that the user can accurately and quickly grasp the contents of the video signal.

That is, a telop often represents a program, such as a program title, or accurately informs the contents, such as a score of a baseball program. When recording on a recording medium or performing variable speed reproduction, the user can effectively grasp the contents by quickly viewing only the scene where the telop appears.

Further, since the recording medium 13 records the telop area information on the telop included in the video signal together with the video signal, the user can grasp the content of the video signal. This recording medium 13 is an embodiment of the specific information recording medium according to the present invention.

[0048]

As described above, the specific region extracting apparatus and method according to the present invention can accurately extract a specific region such as all telops in any environment.

Further, the specific area information recording apparatus and method according to the present invention allow the user to accurately and quickly grasp the contents of the video signal recorded on the recording medium by recording the specific area information.

Further, the specific area information recording medium according to the present invention can accurately and promptly notify the user of the content of the recorded video signal.

[Brief description of the drawings]

FIG. 1 is a block diagram of a telop extraction device which is an embodiment of a specific region extraction device and method according to the present invention.

FIG. 2 is a flowchart for explaining the operation of a uniform luminance area detection circuit in the telop extraction device.

FIG. 3 is a diagram for explaining the operation of a constant-time unchanged pixel detection circuit in the telop extraction device.

FIG. 4 is a flowchart for explaining the operation of an extraction circuit in the telop extraction device.

FIG. 5 is a diagram illustrating a specific example of an original image stored in a video storage unit in the telop extraction device.

FIG. 6 is a diagram showing a specific example of an output result of a uniform luminance region detection circuit in the telop extraction device.

FIG. 7 is a diagram showing a specific example of an output result of a high-frequency region detection circuit in the telop extraction device.

FIG. 8 is a diagram showing a specific example of an output result of a constant-time unchanged pixel detection circuit in the telop extraction device.

9 is a diagram illustrating a specific example of an evaluation value after weighting and adding each of the specific examples of the output results of FIGS. 6, 7, and 8; FIG.

FIG. 10 is a frequency distribution diagram projected on a first orthogonal coordinate system.

FIG. 11 is a frequency distribution diagram projected on a second orthogonal coordinate system.

FIG. 12 is a diagram showing a result of extracting only values larger than a predetermined threshold value in a frequency distribution projected on a first orthogonal coordinate system.

FIG. 13 is a diagram showing a result of extracting only a value larger than a predetermined threshold value in a frequency distribution projected on a second rectangular coordinate system.

FIG. 14 is a diagram showing a telop region finally extracted by extracting a common part from the regions shown in FIGS. 12 and 13;

FIG. 15 is a block diagram of a telop information recording apparatus which is an embodiment of the specific area information recording apparatus and method according to the present invention.

FIG. 16 is a format diagram of write information generated by the telop information recording device.

[Explanation of symbols]

1 telop extraction device, 3 uniform luminance area detection circuit, 4
High-frequency region detection circuit, 5 fixed time constant pixel detection circuit, 6 extraction circuit, 7 video storage unit, 10 telop information recording device, 12 recording system controller

Claims (26)

[Claims] 1. A uniform level area detecting means for detecting an approximately uniform level area by comparing an arbitrary pixel level of a video signal with a peripheral pixel level, and determining whether or not the arbitrary pixel level remains unchanged for a predetermined time or more. Pixel level non-change determining means for determining whether; a high frequency region detecting means for detecting a high frequency component of a frequency component in an arbitrary image plane of the video signal; the uniform level region detecting means and the pixel level no change determining means; Extracting means for extracting a specific area based on each output of the high-frequency area detecting means. 2. The uniform level area detecting means calculates a difference between the arbitrary pixel level and the peripheral pixel level in a block including a predetermined number of pixels centered on an arbitrary pixel,
2. The specific area extracting apparatus according to claim 1, wherein the area of the uniform level is detected according to the number of arbitrary pixels whose level difference is equal to or less than a predetermined threshold. 3. The pixel level non-change determination means, wherein the change of the pixel level on the same coordinate of the video signal of the plurality of frames stored in the video storage means for storing the plurality of frames of the video signal does not change for a predetermined time or more. 2. The specific area extracting apparatus according to claim 1, wherein it is determined whether or not the specific area is a value. 4. The high-frequency area detecting means extracts a high-frequency area in each of two axial directions of a plurality of orthogonal coordinate systems in a plurality of arbitrary directions on a plane where the video signal is developed, and uses the plurality of orthogonal coordinate systems to extract the high-frequency areas. 2. The specific area extracting apparatus according to claim 1, wherein a high frequency of the frequency component is detected by calculating a logical product of the extracted high frequency areas. 5. The extraction means weights each output of the uniform level area detection means, the pixel level invariance determination means and the output of the high frequency area detection means with a predetermined weight, and adds the outputs. 2. The specific area extracting device according to claim 1, wherein an evaluation value is calculated, and the specific area is extracted based on the evaluation value. 6. An arbitrary pixel level of a video signal is compared with peripheral pixel levels to detect a substantially uniform level area, and it is determined whether or not the arbitrary pixel level remains unchanged for a predetermined time or more. Further, a specific area extracting method characterized by detecting a high frequency component of a frequency component in an arbitrary image plane of the video signal and extracting a specific area based on each output. 7. A difference between the arbitrary pixel level and the peripheral pixel level in a block having a predetermined number of pixels centered on the arbitrary pixel, wherein the level difference is equal to or less than a predetermined threshold value. 7. The method according to claim 6, wherein the uniform level area is detected in accordance with the number of pixels. 8. A method for determining whether or not a change in a pixel level on the same coordinate of a plurality of video signals stored in a video storage unit for storing a plurality of frames of the video signal remains unchanged for a predetermined time or more. The method for extracting a specific area according to claim 6, wherein: 9. A high-frequency area in each of two axial directions of a plurality of orthogonal coordinate systems in a plurality of arbitrary directions on a plane where the video signal is developed, and a logical product of the high-frequency areas extracted by the plurality of orthogonal coordinate systems 7. The method according to claim 6, wherein a high frequency band of the frequency component is detected by calculating the following equation. 10. An evaluation value of each pixel is calculated by adding a predetermined weight to each output, and the specific area is extracted based on the evaluation value. 7. The method for extracting a specific region according to 6. 11. A specific area extracting means for extracting a specific area included in an input video signal and outputting specific area information relating to the extracted specific area, and recording the specific area information together with the input video signal on a recording medium. A specific area information recording device, comprising: recording means. 12. The specific area information recording device according to claim 11, wherein the specific area information is appearance position information indicating an appearance position of the specific area. 13. A uniform level area detecting means for comparing an arbitrary pixel level of a video signal with a peripheral pixel level to detect a substantially uniform level area, wherein the specific pixel level is maintained for a predetermined time. Pixel level invariance determining means for determining whether or not there is no change, high frequency area detecting means for detecting a high frequency component of a frequency component in an arbitrary image plane of the video signal, uniform level area detecting means, 12. The specific area information recording apparatus according to claim 11, further comprising: a pixel level non-change determining means; and an extracting means for extracting a specific area based on each output of the high frequency area detecting means. 14. The uniform level region detecting means calculates a difference between the arbitrary pixel level and the peripheral pixel level in a block including a predetermined number of pixels centered on an arbitrary pixel, and determines the level difference as a predetermined value. 12. The specific area information recording apparatus according to claim 11, wherein the area of the uniform level is detected according to the number of arbitrary pixels that are equal to or smaller than a threshold value. 15. The pixel level no change determination means, wherein the change of the pixel level on the same coordinate of the video signal of the plurality of frames stored in the video storage means for storing the plurality of frames of the video signal does not change for a predetermined time or more. 12. The specific area information recording device according to claim 11, wherein it is determined whether or not the specific area information is satisfied. 16. The high-frequency area detecting means extracts a high-frequency area in each of two axial directions of a plurality of orthogonal coordinate systems in a plurality of arbitrary directions on a plane where the video signal is developed, and uses the plurality of orthogonal coordinate systems. 12. The specific area information recording device according to claim 11, wherein a high frequency of the frequency component is detected by calculating a logical product of the extracted high frequency areas. 17. The extraction unit according to claim 1, wherein each of the outputs of the uniform level region detection unit, the pixel level invariance determination unit, and the high frequency region detection unit is added with a predetermined weight. The specific area information recording apparatus according to claim 11, wherein an evaluation value is calculated, and the specific area is extracted based on the evaluation value. 18. A specific area information recording method, wherein a specific area included in an input video signal is extracted, and specific area information relating to the extracted specific area is recorded together with the input video signal on a recording medium. 19. The specific area information recording method according to claim 18, wherein the specific area information is appearance position information indicating an appearance position of the specific area. 20. A method for comparing an arbitrary pixel level of a video signal with a peripheral pixel level to detect a substantially uniform level area, and determining whether or not the arbitrary pixel level remains unchanged for a predetermined time or more. Further, after detecting a high frequency component of a frequency component in an arbitrary video plane of the video signal and extracting a specific region based on each of these outputs, specific region information relating to the specific region is recorded together with the input video signal on a recording medium. 19. The specific area information recording method according to claim 18, wherein the information is recorded in a specific area. 21. A difference between the arbitrary pixel level and the peripheral pixel level in a block consisting of a predetermined number of pixels centered on the arbitrary pixel, wherein the level difference is equal to or less than a predetermined threshold value. 19. The specific area information recording method according to claim 18, wherein the uniform level area is detected in accordance with the number of pixels. 22. Determining whether or not a change in a pixel level on the same coordinate of a plurality of frames of video signals stored in a video storage unit storing a plurality of frames of the video signal remains unchanged for a predetermined time or more. 19. The specific area information recording method according to claim 18, wherein: 23. A high-frequency area in each of two axial directions of a plurality of orthogonal coordinate systems in a plurality of arbitrary directions on a plane on which the video signal is developed, and a logical product of the high-frequency areas extracted by the plurality of orthogonal coordinate systems 19. The specific area information recording method according to claim 18, wherein a high band of the frequency component is detected by calculating the following. 24. An evaluation value of each pixel is calculated by adding a predetermined weight to each output, and the specific area is extracted based on the evaluation value. 18. The method for recording specific area information according to item 18. 25. A specific area information recording medium, wherein specific area information on a specific area included in a video signal is recorded together with the video signal. 26. The specific area information recording medium according to claim 25, wherein the specific area information is appearance position information indicating an appearance position of the specific area.