HK1181589A - Video processing device, video processing method, video processing program, and memory medium - Google Patents

Description

Video processing device, video processing method, video processing program, and storage medium

Technical Field

The present invention relates to a technique of processing noise of a video.

Background

Conventionally, techniques for reducing noise generated in decoding a compression-encoded video have been developed.

Patent document 1 describes the following technique: a weighting coefficient is set based on a distance from a coding block boundary of block coding, and an image quality correction amount in image quality correction is controlled based on the weighting coefficient.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. Hei 10-229546

Disclosure of Invention

Technical problem to be solved by the invention

The technique described in patent document 1 is premised on obtaining a distance from an encoded block boundary of block encoding. Therefore, in an apparatus that cannot acquire the distance, the same method cannot be employed, and noise reduction processing and image quality correction processing cannot be performed.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a video processing technique capable of performing noise reduction processing and image quality correction using a general configuration used for decoding processing.

Technical scheme for solving technical problem

The video processing device counts the number of blocks in which a quantization parameter of a video exceeds a predetermined threshold, and calculates the amount of noise in the video based on the count result. In addition, the noise reduction amount is adjusted according to the calculated noise amount.

Effects of the invention

According to the video processing apparatus of the present invention, since the noise amount is calculated based on whether or not the quantization parameter exceeds the predetermined threshold, if the quantization parameter can be acquired, the noise reduction processing and the image quality correction can be performed. Since the quantization process is adopted in a plurality of image encoding systems such as MPEG2, for example, it can be said that the noise reduction process and the image quality correction can be performed in many cases. That is, it is advantageous in that no special method is required for calculating the noise amount.

Drawings

Fig. 1 is a functional block diagram of a video processing apparatus 100 according to embodiment 1.

Fig. 2 is an operation flowchart of the video processing apparatus 100 according to embodiment 2.

Fig. 3 is a functional block diagram of the video processing apparatus 100 according to embodiment 4.

Fig. 4 is a functional block diagram of the video processing apparatus 100 according to embodiment 5.

Fig. 5 is a diagram schematically showing a relationship between the amount of video correction performed by the video processing apparatus 100 and the amount of noise in the video.

Detailed Description

< embodiment 1 >

Fig. 1 is a functional block diagram of a video processing apparatus 100 according to embodiment 1 of the present invention. The video processing apparatus 100 is an apparatus for correcting noise of an input video signal, and includes: the video acquisition unit 110, the decoding processing unit 120, the quantization parameter acquisition unit 130, the storage unit 140, the noise amount calculation unit 150, and the noise reduction processing unit 160.

The video acquisition unit 110 receives a video signal obtained by converting a video into a signal. The source of the video signal may be any type of video signal source such as a broadcast wave, video data stored in a storage medium, or the like. Among these, a video signal using a method capable of acquiring quantization parameters described later is required.

The decoding processing unit 120 decodes the video signal acquired by the video acquisition unit 110. Since a video signal is usually encoded by some method, the decoding processing unit 120 is required to perform processing.

The quantization parameter acquisition unit 130 acquires a quantization parameter used in the process of decoding the video signal by the decoding processing unit 120. In many image encoding methods, quantization processing is performed when encoding a video. Since the quantization parameter at this time is required for the decoding process, the quantization parameter at this time is forwarded to the side on which the decoding process is performed in some form. For example, the quantization parameter for each video block may be recorded in a header portion of the video stream, or the like. The quantization parameter acquisition unit 130 acquires the quantization parameter in accordance with the format adopted by the encoding method.

In addition, although the quantization parameter cannot be obtained when the video is not encoded, the method according to the present invention is not necessarily adopted since noise generated by encoding does not occur unless encoding processing is performed.

The storage unit 140 stores a threshold value for calculating the noise amount of the video using the quantization parameter. The threshold is used when determining whether or not video blocks to which the quantization parameter is applied are to be removed more high-frequency components based on the size of the value of the quantization parameter.

The noise amount calculation unit 150 calculates the noise amount of the video using the quantization parameter acquired by the quantization parameter acquisition unit 130 and the threshold stored in the storage unit 140. The calculation method will be described later.

The noise reduction processing unit 160 performs noise reduction processing of the video based on the noise amount calculated by the noise amount calculation unit 150. Specifically, the processing corresponds to, for example, processing for removing high-frequency components of a video, processing for reducing noise generated at a boundary portion of an image, or the like.

The video acquisition Unit 110, the decoding Processing Unit 120, the quantization parameter acquisition Unit 130, the noise amount calculation Unit 150, and the noise reduction Processing Unit 160 may be realized by hardware such as a circuit device that realizes their functions, or may be configured by an arithmetic device such as a microcomputer or a CPU (Central Processing Unit) and software that defines their operations.

The storage unit 140 may be configured by a storage device such as an HDD (Hard Disk Drive).

The configuration of the video processing apparatus 100 according to embodiment 1 is explained above. Next, a process of calculating the noise amount of video by the video processing apparatus 100 will be described together with a basic idea.

< embodiment 1: idea for calculating noise amount

Generally, quantization processing is performed when a video signal is encoded. It can be said that the main purpose of this processing is to refine the high frequency components of the video signal to compress the amount of information. For example, the amplitude value of each frequency component is divided by the quantization parameter, thereby reducing the magnitude of the amplitude value. This reduces the number of bits required for representing the amplitude value of each frequency component, and can also perform processing such as simplification, that is, approximating a minute amplitude value to 0. As a result, the amount of information required for representing the video can be reduced.

When encoding a video signal, a video is divided into a plurality of regions (blocks), and encoding processing and quantization processing are sometimes performed on each block. In this case, a different quantization parameter may be used for each block. A larger value of the quantization parameter for a block means that more high frequency components are refined during the encoding process. That is, when decoding a block having a large value of a quantization parameter, it is considered that noise is likely to occur in a decoded video because a large amount of high-frequency components are lost.

The present invention focuses on the point that the magnitude of the amount of noise after decoding in the block is estimated using the magnitude of the value of the quantization parameter. In an encoding method in which quantization processing is performed when encoding processing is performed, a quantization parameter should be always available even at the decoding side. Therefore, in the coding method using quantization, the amount of noise is calculated by using the quantization parameter, which has the following advantages: the amount of noise can be reliably calculated without employing a special encoding method or calculation method.

By performing correction processing (noise reduction processing) suitable for the amount of noise on the video after the amount of noise is calculated, it is possible to perform optimum correction processing, that is, to reduce the amount of correction for blocks with less noise; the correction amount is increased for the block with more noise.

< embodiment 1: noise reduction step >

Next, a procedure in which the video processing apparatus 100 calculates a noise amount and performs noise reduction processing using the noise amount will be described.

(step 1: acquiring video signal)

The video acquisition unit 110 acquires a video signal from an arbitrary video signal source.

(step 2: obtaining quantization parameter)

The decoding processing unit 120 decodes the video signal acquired by the video acquisition unit 110. The quantization parameter acquisition unit 130 acquires a quantization parameter obtained in the process of decoding a video signal. Under the condition that a quantization parameter is set in each block in a video, the quantization parameter of each block is obtained.

(step 2: obtaining quantization parameter: supplement)

The method of the quantization parameter acquisition unit 130 acquiring the quantization parameter differs depending on the encoding method. For example, as described above, when a quantization parameter is recorded in the video signal itself, the value may be acquired. Although it is not always necessary to derive the quantization parameter from the video signal itself, the value of the quantization parameter is required when the decoding process is performed regardless of the encoding method used, and thus the value may be obtained.

(step 3: obtaining threshold)

The noise amount calculation unit 150 acquires the quantization parameter acquired by the quantization parameter acquisition unit 130. In addition, a threshold value for calculating the noise amount of the video based on the quantization parameter is acquired from the storage unit 140.

(step 4: calculating noise amount)

The noise amount calculation unit 150 counts the number of blocks in which the value of the quantization parameter exceeds the threshold among the video blocks in the video. The noise amount calculation unit 150 calculates the noise amount of the video using the count result.

(step 4: calculating noise amount: supplement 1)

More blocks in which the value of the quantization parameter exceeds the threshold value means that the number of blocks from which more high-frequency components are removed is larger. When decoding a block from which a large amount of high-frequency components are removed, it is considered that the difference between before and after encoding is large, and therefore the block is treated as a block having large noise after decoding. Since the more blocks that are considered to be noisy, the larger the noise amount of the entire video, the noise amount is defined by the number of blocks whose quantization parameter exceeds the threshold.

(step 4: calculating noise amount: supplement 2)

The number of blocks whose quantization parameter exceeds the threshold may be itself used as the noise amount, or some calculation formula may be applied thereto to recalculate the noise amount. In any case, they have in common: the amount of noise in the video is calculated based on the number of partitions whose quantization parameter exceeds a threshold. This point is also the same in the following embodiments.

(step 5: noise reduction treatment)

The noise reduction processing unit 160 adjusts the amount of noise reduction of the video based on the amount of noise calculated by the noise amount calculation unit 150, and then performs noise reduction processing. Specifically, the greater the amount of noise in the video, the stronger the intensity of the noise reduction processing. For example, the amount of reduction of the high-frequency component removed by the high-frequency filter (filter gain) is increased.

(step 5: noise reduction processing: supplement 1)

Since the quantization process is a process of removing high-frequency components during encoding, increasing the amount of removal of high-frequency components in this step can be regarded as removing high-frequency components doubly. However, when decoding a video from which a high-frequency component has been removed during encoding, the original high-frequency component is lost during encoding, and therefore high-frequency noise may be generated instead. As a typical example thereof, block noise (block noise) exists, that is, it looks as if an image is divided into a lattice shape at a block boundary. Thus, this step is also considered necessary in order to effectively remove noise generated after decoding.

(step 5: noise reduction processing: supplement 2)

As a reference for calculating the amount of noise after decoding, the quantization parameter is used in embodiment 1. The reason for this is that the decoding side must be able to acquire the quantization parameter, and in addition, the quantization parameter implies the degree of information compression. That is, since a large value of the quantization parameter means that a large amount of high-frequency components are removed, it is considered that a large amount of noise is generated after decoding. Therefore, it is considered appropriate to estimate the noise amount based on the magnitude of the quantization parameter. The present invention can effectively utilize the above dual advantages, and is advantageous in this respect.

< embodiment 1: conclusion

As described above, the video processing apparatus 100 according to embodiment 1 calculates the noise amount of the video using the number of blocks whose quantization parameter value exceeds the threshold value. When quantization processing is performed during video encoding, it is considered that the quantization parameter can be acquired also on the decoding side, and therefore, it is not necessary to use special information or use a special calculation method for calculating the noise amount, and the noise amount can be reliably calculated.

In embodiment 1, the noise amount is calculated using the number of blocks whose quantization parameter value exceeds the threshold value, based on the following concept: that is, if a block in which a high frequency component is removed more in the encoding process is decoded, more noise is generated. Thus, since the noise amount can be calculated in accordance with the procedure of the encoding process, it can be said that the noise amount according to the image characteristics can be obtained.

In embodiment 1, the noise reduction amount is adjusted based on the calculated noise amount. This makes it possible to avoid the problem that increasing the noise reduction amount for a video with less noise increases the noise, and to perform appropriate noise reduction processing.

< embodiment 2 >

In embodiment 1, the noise amount is calculated based on whether or not the quantization parameter exceeds a threshold. In embodiment 2 of the present invention, the values of the quantization parameter are segmented into a plurality of levels based on the magnitude of the values of the quantization parameter, and accumulated after being multiplied by weighting coefficients given to the respective levels. This makes it possible to analyze the degree of noise in the video in more detail and to calculate the amount of noise after decoding more appropriately. Since the configuration of the video processing apparatus 100 is the same as that of embodiment 1, the following description will focus on differences from the above-described calculation method.

Fig. 2 is an operation flowchart of the video processing apparatus 100 according to embodiment 2. Next, the respective steps of fig. 2 will be explained.

(FIG. 2: step S200)

When the video signal is acquired by the video acquisition unit 110, the present operation flow starts. The decoding processing unit 120 decodes the video signal acquired by the video acquisition unit 110.

(FIG. 2: step S201)

As described in embodiment 1, the quantization parameter acquiring unit 130 acquires the quantization parameter of each video block obtained in the process of the decoding process.

(FIG. 2: Steps S202 to S204)

The noise amount calculation unit 150 divides the value of the quantization parameter of each video block acquired by the quantization parameter acquisition unit 130 into a plurality of levels according to the size thereof. Here, an example of division into 3 levels is shown, but not limited thereto. The noise amount calculation unit 150 determines which of the 3 levels the value of the quantization parameter belongs to.

(FIG. 2: Steps S205-S207)

The noise amount calculation unit 150 multiplies the quantization parameter by a predetermined weighting coefficient according to the level to which the value of the quantization parameter belongs. In embodiment 1, the value of the quantization parameter is used without any change, but in embodiment 2, the value multiplied by a weighting coefficient is used. By adjusting the weighting coefficient, the process of calculating the noise amount can be adjusted more finely.

(FIG. 2: Steps S205-S207: supplement 1)

The weighting coefficients in this step may not necessarily be common for all partitions. For example, the following adjustment and the like may be performed: for the blocks deemed to be of low importance, the weighting coefficients of the respective levels are reduced as a whole, and for the blocks deemed to be of high importance, LV 2-3 are set higher than the other blocks.

(FIG. 2: Steps S205-S207: supplement 2)

The value of the weighting coefficient may be stored in a storage device such as the storage unit 140 in advance, and may be read out as needed.

(FIG. 2: step S208)

The noise amount calculation unit 150 determines whether or not the above-described procedure is performed for all the blocks of the entire screen. If not, the process returns to step S202 and repeats the same, and if so, the process proceeds to step S209.

(FIG. 2: Steps S209 to S211)

As in embodiment 1, the noise amount calculation unit 150 counts the number of blocks for which the value of the quantization parameter exceeds the threshold, and calculates the noise amount of the video based on the result. The difference from embodiment 1 is that in this embodiment, the weighting coefficient is multiplied by the quantization parameter and then compared with the threshold value. The processing of the noise reduction processing unit 160 is the same as that of embodiment 1.

< embodiment 2: conclusion

As described above, according to embodiment 2, the noise amount calculation unit 150 ranks the quantization parameters and assigns weighting coefficients to the respective levels. The noise amount calculation unit 150 calculates the noise amount of the video by adding up the results of multiplying the quantization parameter by the weighting coefficient. This makes it possible to adjust the weighting coefficient in addition to the threshold value stored in the storage unit 140, and thus it is possible to more finely adjust the process of calculating the noise amount.

For example, in addition to the method of adjusting the weighting coefficients according to the importance of each block as described above, a method of adjusting the weighting coefficients according to the type of video, or the like may be used. The adjustment of the threshold value or the weighting factor may be dynamically performed every time the video is input, or a plurality of previously assumed combination patterns may be prepared and stored in the storage unit 140 so that any one of them is used at the time of the video input.

< embodiment 3 >

In embodiments 1 to 2, the number of blocks whose quantization parameter exceeds a threshold is counted, and the value is adopted as the noise amount of the video. As another modification, the number of blocks whose quantization parameter exceeds the threshold value is counted, and the noise amount may be defined as a value obtained by dividing the counted value by the total number of blocks, that is, a ratio of blocks having a large quantization parameter to the whole.

In addition, when the quantization parameter is multiplied by the weighting coefficient as in embodiment 2, a value obtained by dividing the finally obtained count result by the total number of blocks, that is, a ratio of blocks having a large weighted quantization parameter to the whole may be defined as the noise amount of the video.

< embodiment 4 >

Fig. 3 is a functional block diagram of the video processing apparatus 100 according to embodiment 4 of the present invention. The video processing apparatus 100 according to embodiment 4 includes the high-frequency filter 161 and the edge filter 162 as the internal functions of the noise reduction processing unit 160 in the configurations described in embodiments 1 to 3. The other structures are the same as those of embodiments 1 to 3.

The high-frequency filter 161 is a filter for removing a high-frequency component of the video signal decoded by the decoding processing unit 130. The high-frequency filter 161 performs a process of removing a high-frequency component on the entire screen of the video signal decoded by the decoding processing unit 130. Further, it is constituted so that the amount of the removed high-frequency component (filter gain) can be changed.

The edge filter 162 is a filter for removing noise (edge noise) generated in the contour portion of the video signal decoded by the decoding processing unit 130. For example, mosquito noise or the like generated on an edge portion of an image is removed. The edge filter 162 performs a process of removing edge noise on the entire screen of the video signal decoded by the decoding processing unit 130. Further, it is constituted so that the amount of the removed high-frequency component (filter gain) can be changed.

In embodiment 4, the noise amount calculation unit 150 adjusts the noise reduction amount of the high frequency filter 161 and the noise reduction amount of the edge filter 162 based on the calculated noise amount. Specifically, the larger the amount of noise in the video, the larger the amount of noise reduction of each filter, the lower the noise after decoding.

In embodiment 4, since noise is reduced by the noise filter, the filter gain may be adjusted to adjust the amount of reduction in noise. In the case where the noise is reduced by other methods, the amount of reduction of the noise is adjusted corresponding to the method.

< embodiment 4: conclusion

As described above, according to embodiment 4, the noise amount calculation unit 150 adjusts the filter gain of each noise filter based on the calculated noise amount. This makes it possible to adjust the noise correction processing amount based on the calculated noise amount.

< embodiment 5 >

Fig. 4 is a functional block diagram of the video processing apparatus 100 according to embodiment 5 of the present invention. The video processing apparatus 100 according to embodiment 5 includes a coring processing unit 171 and a sharpening processing unit 172, in addition to the configurations described in embodiments 1 to 4. The other structures are the same as those of embodiments 1 to 4.

In fig. 4, an example is shown in which a coring noise reduction processing unit 171 and a sharpening processing unit 172 are provided in addition to the configuration described in embodiment 4, but a coring noise reduction processing unit 171 and a sharpening processing unit 172 may be provided in the configuration of another embodiment.

The coring processing unit 171 performs processing for removing minute high-frequency components from the entire screen of the video subjected to the noise reduction processing by the noise reduction processing unit 160. This is to remove the high frequency component in advance so that the sharpening processing section 172 described below does not enhance the high frequency noise. In particular, the high-frequency filter 161 may not sufficiently remove the blocking noise generated at the boundary portion of the video block. By removing the block noise in advance by the coring processing unit 171, even if the block noise is enhanced by the sharpening processing unit 172, the influence thereof can be suppressed.

The sharpening processing unit 172 performs contour enhancement processing on the entire screen of the video on which the noise reduction processing unit 160 has performed the noise reduction processing. Since the contour enhancement processing has a function of amplifying the high-frequency component, the contour enhancement processing is performed after the minute high-frequency component is removed in advance by the coring processing unit 171.

< embodiment 5: conclusion

As described above, according to embodiment 5, the processing for reducing high-frequency noise is performed based on the calculation result of the noise amount calculation unit 150, and then the contour enhancement processing is further performed by the sharpening processing unit 172, whereby a clear video can be obtained while removing noise.

Further, according to embodiment 5, by removing minute high-frequency noise such as block noise by the coring processing unit 171, it is possible to effectively exhibit the effect of contour enhancement while suppressing the adverse effect of the sharpening processing unit 172.

< embodiment 6 >

In embodiments 4 to 5, the processing objects of the high-frequency filter 161, the edge filter 162, the coring processing unit 171, and the sharpening processing unit 172 are the entire screen of the video, but the processing objects of these respective units may be limited to only partial blocks on the screen. For example, the above-described processing of each section is performed only on a block in which the value of the quantization parameter (or the weighted value of the quantization parameter) exceeds the threshold value.

Thus, it is possible to perform noise reduction processing on a block having a large amount of noise, and to perform sharpening again on an image whose sharpness has been reduced by the noise reduction processing. Further, it is also advantageous compared to embodiments 4 to 5 in that the processing load can be suppressed by limiting the blocks to be processed.

Further, if the noise reduction processing or the sharpening processing is performed only on a specific block, there is a possibility that a balance cannot be obtained with a block close to the block. Therefore, for example, the same noise reduction processing or sharpening processing can be performed on the peripheral region including the block having a large noise amount. This makes it possible to balance with other blocks while suppressing the processing load.

< embodiment 7 >

Fig. 5 is a diagram schematically showing a relationship between the amount of video correction performed by the video processing apparatus 100 according to the present invention and the amount of noise in the video.

Since the noise amount of the video is calculated based on the block in which the value of the quantization parameter exceeds the threshold in the present invention, it is not determined to be noise as long as the value of the quantization parameter does not exceed the threshold. That is, the video correction amount does not increase until the noise amount reaches the threshold value, and is substantially constant.

Since the noise reduction amount of the noise reduction processing unit 160 is increased when the noise amount increases after the noise amount exceeds the threshold, the relationship between the noise amount and the correction amount is proportional.

By adjusting the threshold value and the scaling factor of the noise amount and the correction amount in fig. 5, the processing characteristics of the video processing apparatus 100 can be adjusted. The same effects can be achieved by adjusting the weighting coefficients described in embodiment 2.

Further, the characteristics in the vertical axis direction in fig. 5 can be adjusted by adjusting the noise reduction amount of the noise reduction processing unit 160 and the processing amounts of the coring processing unit 171 and the sharpening processing unit 172.

< embodiment 8 >

In embodiments 1 to 7, the following examples are considered as the sources of acquisition of the video signal by the video acquisition unit 110.

(example 1 of video signal source) a video signal is obtained from an analog video broadcast wave.

(example 2 of video signal source) a video signal is obtained from a digital video broadcast wave.

(example 3 of video signal source) video signals recorded on a recording medium such as a Blu-ray (registered trademark) disc, a DVD (Digital Versatile disc), or an HDD are obtained.

(example 4 of video signal source) a video signal is obtained from a broadcast wave such as an IP broadcast wave or a CATV broadcast wave.

(example 5 of video signal source) a video signal is acquired from an external device such as an external video recording device or an external video acquiring device.

< embodiment 9 >

A program for realizing the processing of each functional unit of the video processing apparatus 100 described in embodiments 1 to 8 may be recorded in a computer-readable storage medium, and the processing of each functional unit may be realized by causing a computer system to read and execute the program recorded in the storage medium. The term "computer System" as used herein refers to a System including hardware such as an OS (Operating System) and peripheral devices.

The program may be a program for realizing a part of the functions, or may be a program for realizing the functions in combination with a program already recorded in a computer system.

The "storage medium" storing the program refers to a computer-readable removable medium such as a flexible disk, a magneto-optical disk, a ROM (read only Memory), a CD-ROM, or a storage device such as a hard disk incorporated in a computer system. Further, the program may be stored dynamically in a short time, such as a communication line for transmitting the program through a network such as the internet or a communication line such as a telephone line; and a device for storing the program for a certain period of time, such as a volatile memory in the computer system serving as the server or the client in this case.

Description of the reference symbols

100: video processing apparatus, 110: video acquisition unit, 120: decoding processing unit, 130: quantization parameter acquisition unit, 140: storage unit, 150: noise amount calculation unit, 160: noise reduction processing unit, 161: high-frequency filter, 162: edge filter, 171: coring noise reduction processing unit, 172: and a sharpening processing unit.

Claims (13)

1. A video processing apparatus that processes video, comprising:

a video acquisition unit that receives a video signal obtained by converting a video into a signal;

a quantization parameter acquisition unit that acquires a quantization parameter for each block in the video;

a storage unit that stores a threshold value for calculating a noise amount of the video;

a noise amount calculation unit that calculates a noise amount of the video using the quantization parameter and the threshold; and

a noise reduction processing unit that performs noise reduction processing on the video on the basis of the noise amount calculated by the noise amount calculation unit,

the noise amount calculation section calculates a noise amount of the video based on the number of the blocks whose values of the quantization parameters exceed the threshold,

the noise reduction processing unit increases or decreases the amount of noise reduction of the video in accordance with the magnitude of the noise amount.

2. The video processing apparatus of claim 1,

the noise amount calculation section, when calculating the noise amount,

segmenting values of a quantization parameter for each block within the video into a plurality of levels,

different weighting coefficients are respectively assigned to the levels,

multiplying the weighting coefficient assigned to the level to which the quantization parameter belongs by the value of the quantization parameter of the block, counting the number of blocks whose value exceeds the threshold value, and calculating the noise amount of the video using the counting result.

3. The video processing apparatus of claim 1,

the noise amount calculation section, when calculating the noise amount,

calculating the amount of noise using a ratio of the number of blocks for which the quantization parameter exceeds the threshold to the number of all blocks within the video.

4. The video processing apparatus of claim 1,

the noise amount calculation section, when calculating the noise amount,

segmenting the quantization parameter for each block within the video into a plurality of levels,

different weighting coefficients are respectively assigned to the levels,

multiplying the weighting coefficient assigned to the level to which the quantization parameter belongs by the value of the quantization parameter of the block, counting the number of blocks whose value exceeds the threshold value, and calculating the noise amount by using the value obtained by dividing the count result by the number of all blocks in the video.

5. The video processing apparatus according to any one of claims 1 to 4,

the noise reduction processing section includes a high frequency filter that removes a high frequency component of the video,

the high-frequency filter increases or decreases the amount of removal of the high-frequency component in accordance with the magnitude of the noise amount.

6. The video processing apparatus according to any one of claims 1 to 5,

the noise reduction processing section includes an edge filter that removes noise on a contour portion of the video,

the edge filter increases or decreases the amount of noise removal on the contour portion according to the magnitude of the noise amount.

7. The video processing apparatus according to any one of claims 1 to 6,

the noise reduction processing unit includes a coring noise reduction unit that performs coring noise reduction processing on the entire screen of the video.

8. The video processing apparatus according to any one of claims 1 to 6,

the noise reduction processing section includes a coring noise reduction section that performs coring noise reduction processing on a block of the blocks within the video for which the quantization parameter exceeds the threshold.

9. The video processing apparatus according to any one of claims 5 to 8,

the noise reduction processing unit includes a sharpening processing unit that performs contour enhancement processing on the entire screen of the video.

10. The video processing apparatus according to any one of claims 5 to 8,

the noise reduction processing section includes a sharpening processing section that applies contour enhancement processing to a block in which the quantization parameter exceeds the threshold among blocks within the video.

11. A video processing method is a method for processing videos and comprises the following steps:

a step of receiving a video signal obtained by converting a video into a signal;

a quantization parameter obtaining step of obtaining a quantization parameter of each block in the video;

a step of acquiring a threshold value for determining whether or not noise higher than a reference value exists in a block in the video from a storage device storing the threshold value;

a noise amount calculation step of calculating a noise amount of the video using the quantization parameter and the threshold; and

a noise reduction processing step of performing noise reduction processing on the video in accordance with the noise amount calculated by the noise amount calculation step,

in the noise amount calculation step, a noise amount of the video is calculated based on the number of the blocks whose values of the quantization parameters exceed the threshold,

in the noise reduction processing step, the amount of reduction of the noise of the video is increased or decreased according to the magnitude of the noise amount.

12. A video processing program characterized by comprising,

causing a computer to perform the video processing method of claim 11.

13. A computer-readable storage medium comprising, in combination,

a video processing program according to claim 12 is stored.