JP5458746B2 - Video playback device, video recording / playback device, and video recording / playback method - Google Patents

Description

  The present invention relates to a video playback device and video recording / playback device for reproducing a video signal enhanced with respect to a recorded signal, or a video recording / playback device for recording / reproducing a video signal enhanced with respect to an input video signal. Yes, for example, when an input video signal is compressed and recorded on a recording medium, and the recorded data is reproduced, a high-frequency component is generated and added to obtain an output signal with high resolution. The emphasis process is performed, and the degree of the emphasis process is changed according to the compression rate when the image is compressed first.

  Generally, an image is reproduced and displayed after appropriate signal processing is performed on a video signal.

  For example, in the image processing apparatus described in Patent Document 1, with respect to a detail image converted to multi-resolution, an enhancement coefficient for a detail image in a desired frequency band is lower than the desired frequency band. A desired frequency band is emphasized by setting based on a signal of a detailed image.

JP-A-9-44651 (paragraph 0031)

  However, in an image processing apparatus that appropriately sets an enhancement coefficient for a detail image in a desired frequency band with respect to a detail image converted to multi-resolution, enhancement processing is inappropriate or insufficient depending on the input image (video signal). Thus, it has been impossible to obtain an output image (video signal) with an appropriate image quality.

  For example, when an image (video signal) subjected to enlargement processing is input as an input image (video signal), an image (video signal) before enlargement processing is placed on the high frequency component side of the frequency spectrum of the input image (video signal). ) Appears as a component (a folded component) in which a part of the frequency spectrum is folded. Therefore, if the high frequency component is simply emphasized, this aliasing component is emphasized, resulting in inappropriate processing. In addition, if the frequency band is limited and only the frequency band that does not include the aliasing component is emphasized, when considering the frequency spectrum, emphasis on the high frequency component side is avoided, resulting in insufficient enhancement processing. End up.

  Further, when an image (video signal) subjected to noise processing is input as an input image (video signal), the frequency spectrum on the high frequency component side is lost due to the noise processing. Therefore, even if an attempt is made to extract a high frequency component, it cannot be extracted, and the image (video signal) may not be sufficiently enhanced.

  In addition, in the case of video data that has been compressed after the video signal data to be handled has been compressed, the higher the compression ratio at the time of compression, the more high-frequency components of the signal are lost. When the same enhancement processing as that of the decompressed data is performed after image compression, the enhancement processing may not be sufficient.

The present invention has been made to solve the above-described problems, and the video playback device and the video recording / playback device of the present invention are:
Compression processing means for performing image compression processing on an input signal and outputting a control signal that changes in accordance with the compression ratio, access means for recording the compressed video data on a recording medium, and recording video data on the recording medium And a signal processing means for performing signal processing on the reproduced signal that has been reproduced through the access means and expanded.
The signal processing unit generates a first intermediate image generating unit that generates a first intermediate image obtained by extracting a component in the vicinity of a specific frequency band of the input image, and generates a second intermediate image obtained by processing the first intermediate image. Second intermediate image generation means, and first addition means for adding the input image and the second intermediate image,
The first intermediate image generating means generates a first high frequency component image obtained by extracting only the high frequency component of the input image, and changes the frequency component of the signal to be extracted according to the control signal from the compression processing means. 1 high-frequency component image generating means and low-frequency component image generating means for taking out only the low-frequency component of the first high-frequency component image and changing the frequency component of the signal to be extracted according to the control signal from the compression processing means Have
The second intermediate image generating means includes a non-linear processing means for generating a non-linear processed image obtained by amplifying each pixel value of the first intermediate image according to the pixel, and only a high frequency component of the non-linear processed image. A second high-frequency component image that generates a second high-frequency component image, and changes a frequency component of a signal to be extracted according to a control signal from the compression processing unit; a first intermediate image; Second addition means for adding the second high-frequency component image, and by changing the signal band setting to be extracted according to the value of the control signal ,
Nonlinear processing means is for generating a nonlinear processed image by amplifying each pixel value of adjacent zero-cross point of the first intermediate image with greater than one amplification factor.

  According to the present invention, in the first intermediate image generation unit that generates the first intermediate image, the high-frequency component image is extracted in the horizontal direction and the vertical direction, and the low-frequency component image is extracted in the horizontal direction and the vertical direction. In the second intermediate image generation means for extracting and generating the second intermediate image, after performing non-linear processing in the horizontal direction and the vertical direction, high-frequency component images are extracted and extracted in the horizontal direction and the vertical direction. Since the frequency range of each high frequency component and low frequency component is changed based on the compression rate, the signal to be output is a signal format with a larger number of horizontal pixels and lines than the recorded signal, Even when a part of an image (video signal) is enlarged, a high frequency component can be sufficiently applied to the image (video signal), and the compression rate can be reduced. When the high-frequency component of the image (video signal) to hear is lost it is possible to increase the degree of emphasis processing.

It is a block diagram of the video recording / reproducing apparatus by Embodiment 1 of this invention. 2 is a configuration diagram of a signal processing means 11. FIG. It is a block diagram of nonlinear processing means 112Ah. It is a block diagram of nonlinear processing means 112Av. It is another block diagram of the video recording / reproducing apparatus by Embodiment 1 of this invention. 3 is a configuration diagram of an enlargement processing unit 13. FIG. It is another block diagram of the video recording / reproducing apparatus by Embodiment 1 of this invention. FIG. 11 is an operation explanatory diagram of the enlargement processing unit 13. FIG. 11 is an operation explanatory diagram of the enlargement processing unit 13. FIG. 10 is an operation explanatory diagram of the intermediate image generation unit 111. 6 is an operation explanatory diagram of the intermediate image generating unit 112. FIG. It is explanatory drawing of the signal which sampled the step edge and step edge by sampling interval S1. It is explanatory drawing of the signal which sampled step edge and step edge by sampling interval S2. FIG. 7 is an explanatory diagram of operations of the intermediate image generation unit 111 and the intermediate image generation unit 112. FIG. 10 is an operation explanatory diagram of the intermediate image generation unit 111. 6 is an operation explanatory diagram of the intermediate image generating unit 112. FIG. It is a block diagram of weighted addition means 112D. It is a flowchart which shows the video recording / reproducing method by Embodiment 2 of this invention. It is a flowchart which shows the process in signal processing step ST4 of FIG. It is a flowchart which shows the process in high frequency component image generation step ST4A1 of FIG. It is a flowchart which shows the process in low frequency component image generation step ST4A2 of FIG. It is a flowchart which shows the process in the nonlinear process step ST4B1 of FIG. It is a flowchart which shows the process in high frequency component image generation step ST4B2 of FIG. It is a flowchart which shows the process in the horizontal direction nonlinear process step ST4B1h of FIG. It is a flowchart which shows the process in the vertical direction nonlinear process step ST4B1v of FIG.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a video recording / reproducing apparatus according to Embodiment 1 of the present invention.

  The video recording / reproducing apparatus of the present invention performs compression processing by the compression processing unit 12 when a signal is input from the input terminal 2a to the access unit 14, and the access unit 14 writes data to a recording medium such as an optical disc. Read out. A video signal that is read data from a recording medium is subjected to decompression processing on the image compression signal by the decompression processing means 15 and then subjected to signal processing by the signal processing means 11, and then the video signal is output from the output terminal 2b. . In addition to the video signal that has undergone signal processing, the compression processing unit 12 outputs a control signal CMP corresponding to the compression rate and sends it to the signal processing means 11.

  FIG. 2 is a diagram showing the configuration of the signal processing means 11 in FIG. The signal processing unit 11 generates an intermediate image D111 that generates an intermediate image D111 obtained by extracting a component in the vicinity of a specific frequency band from the input signal DIN, and an intermediate image generation unit that generates an intermediate image D112 obtained by performing processing described later on the image D111. 112. The addition means 113 adds the input signal DIN and the intermediate image D112. The addition means 113 adds the input signal DIN and the intermediate image D112 and outputs the result as an output signal DOUT.

  The intermediate image generation unit 111 generates a high frequency component image generation unit 111A that generates an image D111A obtained by extracting only a high frequency component from the input signal DIN, and generates a low frequency component image that generates an image D111B obtained by extracting only the low frequency component of the image D111A. It comprises means 111B. From the intermediate image generation unit 111, the image D111B is output as the intermediate image D111.

  The intermediate image generation unit 112 outputs a non-linear processing unit 112A that outputs an image D112A obtained by performing non-linear processing described later on the intermediate image D111, and a high-frequency component image generation unit that outputs an image D112B obtained by extracting only the high-frequency component of the image D112A. 112B, and adding means 112C that outputs an image D112C obtained by adding the intermediate image D111 and the image D112B. From the intermediate image generation means 112, the image D112C is output as the intermediate image D112.

  The high frequency component image generation unit 111A, the low frequency component image generation unit 111B, and the high frequency component image generation unit 112B receive the control signal CMP from the compression processing unit 12 and change the signal band to be extracted.

  The detailed operation of the video recording / reproducing apparatus according to Embodiment 1 of the present invention will be described below.

  The video signal input from the input terminal 2a is input to the access means 14. The access means 14 writes and reads data on a recording medium such as an optical disk, and the signal processing means 11 removes the aliasing component from this signal. The signal processing that adds the high frequency component and the high frequency component in the band above the Nyquist frequency of the input signal is added to the recorded video signal, and the high frequency component that enhances the resolution is output. The

  In the signal processing unit 11, an intermediate image generating unit 111 that generates an intermediate image D111 obtained by extracting components in the vicinity of a specific frequency band from the input signal DIN, and an intermediate image that generates an intermediate image D112 obtained by performing processing described later on the image D111. The signal generated by the generation means 112 is added to the input signal DIN.

  The detailed operation of the intermediate image generating unit 111 will be described.

  The intermediate image generation unit 111 generates an image D111A obtained by extracting only the high frequency component of the input image DIN in the high frequency component image generation unit 111A. High frequency components can be extracted by performing high-pass filter processing. Note that high-frequency components are extracted in each of the horizontal and vertical directions of the image. That is, the high-frequency component image generation unit 111A performs horizontal high-pass filter processing on the input image DIN to generate an image D111Ah in which the high-frequency component is extracted only in the horizontal direction. The image signal D111A includes an image D111Ah and an image D111Av. The image signal D111A includes an image D111Ah and an image D111Av. Note that the horizontal high-frequency component image generation unit 111Ah and the vertical high-frequency component image generation unit 111Av each change the signal band setting to be extracted according to the value of the control signal CMP from the compression processing unit 12.

  Next, the intermediate image generation unit 111 generates an image D111B obtained by extracting only the low frequency component of the image D111A in the low frequency component image generation unit 111B. The low frequency component can be extracted by performing a low pass filter process. The low frequency component is extracted in each of the horizontal direction and the vertical direction. That is, the low-frequency component image generation unit 111B performs horizontal low-frequency component image generation unit 111B that generates an image D111Bh obtained by performing horizontal low-pass filter processing on the image D111Ah, and performs low-pass filter processing in the vertical direction on the image D111Av. It consists of vertical direction low frequency component image generation means 111Bv that generates the image D111Bv that has been performed, and the image D111B consists of an image D111Bh and an image D111Bv. Then, the intermediate image generation unit 111 outputs the image D111B as the intermediate image D111. The intermediate image D111 includes an image D111h corresponding to the image D111Bh and an image D111v corresponding to the image D111Bv. The horizontal direction low frequency component image generation unit 111Bh and the vertical direction low frequency component image generation unit 111Bv are respectively compression processing units similar to the horizontal direction high frequency component image generation unit 111Ah and the vertical direction high frequency component image generation unit 111Av. The signal band setting to be extracted is changed according to the value of the control signal CMP from 12.

  Next, a detailed operation of the intermediate image generating unit 112 will be described.

  First, the intermediate image generation unit 112 generates an image D112A obtained by performing a later-described nonlinear process on the intermediate image D111 in the nonlinear processing unit 112A. Nonlinear processing is performed in each of the horizontal direction and the vertical direction. That is, the non-linear processing unit 112A performs a non-linear process described later on the image D111Bh to generate an image D112Ah, and a vertical non-linear process generates a image D112Av by performing a non-linear process described later on the image D111Bv. The image D112A includes an image D112Ah and an image D112Av.

  The operation of the nonlinear processing means 112A will be described in more detail. The nonlinear processing means 112A includes a horizontal nonlinear processing means 112Ah and a vertical nonlinear processing means 112Av having the same configuration. Here, the horizontal nonlinear processing means 112Ah performs horizontal processing, and the vertical nonlinear processing means 112Av performs vertical processing.

  FIG. 3 is a diagram showing the configuration of the horizontal nonlinear processing means 112Ah. The horizontal non-linear processing means 112Ah includes a zero cross determination means 112Ah1 and a signal amplification means 112Ah2. Note that the image D111h is input to the nonlinear processing means 112Ah as the input image DIN112Ah1.

  The zero-cross determining unit 112Ah1 checks the change in the pixel value in the input image DIN112Ah1 along the horizontal direction. A location where the pixel value changes from a positive value to a negative value or from a negative value to a positive value is regarded as a zero cross point, and the position of the pixel before and after the zero cross point is transmitted to the signal amplifying unit 112Ah2 by the signal D112Ah1. . For example, pixels located on the left and right of the zero cross point are recognized as pixels located before and after the zero cross point.

  Based on the signal D112Ah1, the signal amplifying unit 112Ah2 identifies the pixels before and after the zero cross point, and amplifies the pixel value only for the pixels before and after the zero cross point (increases the absolute value). Generate. That is, the amplification factor is set to a value larger than 1 for the pixel values of the pixels before and after the zero cross point, and the amplification factor is set to 1 for the pixel values of the other pixels.

  Then, the nonlinear processing image D112Ah2 is output as the image D112Ah from the horizontal nonlinear processing means 112Ah.

  FIG. 4 is a diagram showing the configuration of the vertical nonlinear processing means 112Av. The vertical nonlinear processing means 112Av includes a zero-cross determination means 112Av1 and a signal amplification means 112Av2. Note that the image D111v is input to the nonlinear processing means 112Av as the input image DIN112Av1.

  The zero-cross determining unit 112Av1 confirms the change of the pixel value in the input image DIN112Av1 along the vertical direction. A location where the pixel value changes from a positive value to a negative value or from a negative value to a positive value is regarded as a zero cross point, and the position of the pixel before and after the zero cross point is transmitted to the signal amplifying unit 112Av2 by the signal D112Av1. . For example, pixels positioned above and below the zero cross point are recognized as pixels positioned before and after the zero cross point.

  Based on the signal D112Av2, the signal amplifying unit 112Av2 identifies pixels before and after the zero-cross point, and amplifies the pixel value only for the pixels before and after the zero-cross point (increases the absolute value). Generate. That is, the amplification factor is set to a value larger than 1 for the pixel values of the pixels before and after the zero cross point, and the amplification factor is set to 1 for the pixel values of the other pixels.

  The above is the operation of the nonlinear processing means 112A.

  Next, the intermediate image generation unit 112 generates an image D112B obtained by extracting only the high frequency component of the image D112A in the high frequency component image generation unit 112B. High frequency components can be extracted by performing high-pass filter processing. Note that high-frequency components are extracted in each of the horizontal and vertical directions of the image. That is, the high-frequency component image generation unit 112B performs a horizontal high-frequency component image generation unit 112Bh that generates an image D112Bh obtained by performing a horizontal high-pass filter process on the image D112Ah, and a vertical high-pass filter process on the image D112Av. It consists of vertical high frequency component image generation means 112Bv that generates the performed image D112Bv, and image D112B consists of image D112Bh and image D112Bv. The horizontal direction high frequency component image generation means 112Bh and the vertical direction high frequency component image generation means 112Bv are respectively similar to the horizontal direction high frequency component image generation means 111Ah and the vertical direction high frequency component image generation means 111Av. The signal band setting to be extracted is changed according to the value of the control signal CMP from 19a.

  Next, the adding unit 112C adds the intermediate image D111 and the image D112B to generate an image D112C. Note that the intermediate image D111 includes the image D111h and the image D111v, and the image D112B includes the image D112Bh and the image D112Bv. Means to add all of. The intermediate image generation unit 112 outputs the image D112C as the intermediate image D112.

  The operation of the adding means 113 will be described. The adding means 113 generates an output image DOUT obtained by adding the input image DIN and the intermediate image D112. The output image DOUT is output as an output image (video signal).

  Hereinafter, an operation example of the enlargement processing means and the signal processing means in the video recording / reproducing apparatus of the present invention will be described. In the following description, the symbol Fn represents the Nyquist frequency of the input image DIN unless otherwise specified.

  The operation of the signal processing unit 11 has been described above. The case where the enlargement processing unit 13 is provided in the previous stage of the signal processing unit 11 as shown in FIG. Thus, it is considered that this also serves as an explanation of an emphasis processing method that compensates for a high-frequency component lost when the decompression circuit 15 in the configuration of the present application decompresses and reproduces. The enlargement processing unit 13 generates, for example, an image obtained by enlarging the input image (video signal) twice in both the horizontal and vertical directions. The Nyquist frequency of the enlarged image signal is input. It becomes half of the Nyquist frequency Fn of the image D15.

  When the image size of the reproduction signal reproduced from the recording medium 3 is smaller than the image size output from the terminal 2b, the enlargement processing means 13 displays an image (video signal) obtained by enlarging the reproduction signal reproduced from the recording medium 3. Output. Here, a bicubic method or the like can be used as means for enlarging the image.

  The signal processing means 11 in the present invention outputs an image (video signal) D11 obtained by performing the above-described processing on the input image (video signal) D13.

  Hereinafter, assuming that the number of pixels of the original image DORG is half the number of pixels of the output signal in both the horizontal direction and the vertical direction, the operation and action of the enlargement processing unit 13 will be described first.

  FIG. 6 is a diagram showing the configuration and operation of the enlargement processing means 13. The enlargement processing means 13 includes a horizontal direction zero insertion means 131, a horizontal direction low frequency component passing means 132, a vertical direction zero insertion means 133, and a vertical direction low frequency. The component passing means 134 is included. The horizontal zero insertion means 131 generates an image D131 in which pixels having a pixel value of 0 in the horizontal direction of the input signal DORG are appropriately inserted. The horizontal low frequency component passing means 132 generates an image D132 obtained by extracting only the low frequency component of the image D131 by low-pass filter processing. The vertical direction zero insertion means 133 generates an image D133 in which pixels having a pixel value of 0 in the vertical direction of the image D132 are appropriately inserted. The vertical direction low frequency component passing means 134 generates an image D134 in which only the low frequency components of the image D133 are extracted. The image D134 is output from the enlargement processing means as an image obtained by doubling the original image DORG in both the horizontal and vertical directions.

  FIG. 8 is a diagram for explaining the operation of the enlargement processing means 13 in detail. FIG. 8A shows the original image DORG, FIG. 8B shows the image D131, FIG. 8C shows the image D132, and FIG. 8 (D) represents the image D133, and FIG. 8 (E) represents the image D134. 8A to 8E, a square represents a pixel, and a symbol or a numerical value written therein represents a pixel value of each pixel.

  The horizontal zero insertion means 131 inserts one pixel having a pixel value of 0 for each pixel in the horizontal direction into the original image DORG shown in FIG. 8A, and creates an image D131 shown in FIG. 8B. Generate. The horizontal low frequency component passing means 132 performs a low-pass filter process on the image D131 shown in FIG. 8B to generate an image D132 shown in FIG. The vertical zero insertion means 133 inserts one pixel having a pixel value of 0 for each pixel in the vertical direction into the image D132 shown in FIG. 8C, and the image D133 shown in FIG. Generate. The low frequency component passing means 134 in the vertical direction performs low pass filter processing on the image D133 shown in FIG. 8D to generate an image D134 shown in FIG. With the above processing, an image D134 is generated by enlarging the original image DORG twice in both the horizontal and vertical directions.

  FIG. 9 shows the effect of processing by the enlargement processing means 13 on the frequency space. FIG. 9A shows the frequency spectrum of the original picture DORG, FIG. 9B shows the frequency spectrum of the image D131, and FIG. ) Represents the frequency response of the horizontal frequency component passing means 132, and FIG. 9D represents the frequency spectrum of the image D132. In FIG. 9, the horizontal axis represents the frequency axis representing the spatial frequency in the horizontal direction, and the vertical axis represents the frequency spectrum or the intensity of the frequency response. The number of pixels of the original image DORG is half that of the input image (video signal) DIN. In other words, the sampling interval of the original image DORG is twice that of the input image (video signal) DIN. Therefore, the Nyquist frequency of the original image DORG is half of the Nyquist frequency of the input image (video signal) DIN, that is, Fn / 2.

  In FIG. 9, only one frequency axis is used to simplify the notation. However, usually, image data consists of pixel values given on a pixel array arranged in a two-dimensional plane, and its frequency spectrum is also given on a plane stretched by a horizontal frequency axis and a vertical frequency axis. It is. Therefore, in order to accurately represent the frequency spectrum of the original picture DORG or the like, it is necessary to describe both the horizontal frequency axis and the vertical frequency axis. However, the shape of the frequency spectrum usually spreads isotropically around the origin on the frequency axis, and as long as the frequency spectrum in the space spanned by one frequency axis is shown, the frequency axis It is easy for those skilled in the art to expand and consider the space spanned by two. Therefore, unless otherwise specified in the following description, the description on the frequency space is performed using a space stretched by one frequency axis.

  First, the frequency spectrum of the original picture DORG will be described. Normally, a natural image is input as the original image DORG, but its spectral intensity is concentrated around the origin of the frequency space. Therefore, the frequency spectrum of the original picture DORG is a spectrum SPO represented as shown in FIG.

  Next, the spectral intensity of the image D131 will be described. The image D131 is generated by inserting one pixel per pixel and a pixel value of 0 in the horizontal direction with respect to the original image DORG. When such processing is performed, aliasing around the Nyquist frequency of the original picture DORG occurs in the frequency spectrum. That is, since a spectrum SPM in which the spectrum SPO is folded around the frequency ± Fn / 2 is generated, the frequency spectrum of the image D131 is expressed as shown in FIG.

  Next, the frequency response of the horizontal low frequency component passing means 132 will be described. Since the horizontal low-frequency component passing means is realized by a low-pass filter, the frequency response becomes lower as the frequency becomes higher as shown in FIG.

  Finally, the frequency spectrum of the image D132 will be described. An image D132 is obtained by performing low-pass filter processing having the frequency response shown in FIG. 9C on the image D131 having the frequency spectrum shown in FIG. 9B. Accordingly, as shown in the image D132, the frequency spectrum of the image D132 includes a spectrum SP2 in which the intensity of the spectrum SPM has dropped to some extent and a spectrum SP1 in which the intensity of the spectrum SPO has dropped to some extent. In general, the frequency response of the low-pass filter decreases as the frequency increases. Therefore, when the intensity of the spectrum SP1 is compared with the spectrum SPO, the spectrum intensity on the high frequency component side, that is, the frequency near ± Fn / 2 is reduced by the horizontal low frequency component passing means 132.

  Of the processing performed by the image enlarging means 13, the description of the operation on the frequency space of the processing performed by the vertical zero insertion means 133 and the vertical low frequency component passing means 134 is omitted. It can be easily understood that there is an action similar to the content described with reference to FIG. 9 with respect to the axial direction representing the vertical spatial frequency. That is, the frequency spectrum of the image D134 is obtained by spreading the frequency spectrum illustrated in FIG. 9D in two dimensions.

  In the following description, the spectrum SP2 is referred to as a folded component. This aliasing component appears on the image as noise or a false signal having a relatively high frequency component. Such noise or false signals include overshoot, jaggy or ringing.

  The operation and effect of the video recording / reproducing apparatus according to the present invention will be described below.

  10A to 10E generate an intermediate image D111 from the input image (video signal) DIN when the image D134 obtained by enlarging the original image DORG is input as the input image (video signal) DIN. FIG. 10A schematically shows the frequency spectrum of the input image (video signal) DIN, and FIG. 10B shows the frequency response of the high-frequency component image generating means 1. 10C shows the frequency response of the low-frequency component image generation means 2, FIG. 10D shows the frequency response of the intermediate image generation means 111, and FIG. 10E shows the frequency spectrum of the intermediate image D111. In FIG. 10, only one frequency axis is used for the same reason as in FIG.

  Further, in FIG. 10, the intensity of the frequency spectrum or frequency response is shown only in the range where the spatial frequency is 0 or more. However, the frequency spectrum or frequency response in the following description is symmetrical about the origin on the frequency axis. Shape. Therefore, the figure used for description is sufficient to show only the range where the spatial frequency is 0 or more.

  First, the frequency spectrum of the input image (video signal) DIN will be described. As shown in FIG. 10A, the frequency spectrum of the input image (video signal) DIN has the same shape as that described in FIG. 8D, and the spectrum SPO of the original picture DORG has a certain decrease in intensity. It consists of SP1 and spectrum SP2 which is a folded component.

  Next, the frequency response of the high frequency component image generation unit 111A will be described. Since the high-frequency component image generation unit 111A is configured by a high-pass filter, the frequency response becomes lower as the frequency becomes lower as shown in FIG.

  Next, the frequency response of the low frequency component image generation unit 111B will be described. Since the low-frequency component image generation unit 111B is configured by a low-pass filter, the frequency response thereof becomes lower as the frequency becomes higher as shown in FIG.

  Next, the frequency response of the intermediate image generating unit 1 will be described. Of the frequency components of the input image (video signal) DIN, the frequency components in the region RL1 on the low frequency component side shown in FIG. 10D are the high frequency component image generating unit 111A in the intermediate image generating unit 111. It is weakened by. On the other hand, the frequency components in the region RH1 on the high frequency component side shown in FIG. 10D are weakened by the low frequency component image generating unit 111B in the intermediate image generating unit 111. Therefore, as shown in FIG. 10D, the frequency response of the intermediate image generating unit 111 has a peak in the intermediate region RM1 in which the band is limited by the region RL1 on the low frequency component side and the region RH1 on the high frequency component side. It will have.

  Next, the frequency spectrum of the intermediate image D111 will be described. The input image (video signal) DIN having the frequency spectrum shown in FIG. 10A passes through the intermediate image generating means 111 having the frequency response shown in FIG. 10D, whereby an intermediate image D111 is obtained. The frequency response of the intermediate image generation means 111 has a peak in the intermediate region RM1 band-limited by the region RL1 on the low frequency component side and the region RH1 on the high frequency component side, so the frequency spectrum of the intermediate image D111 is In the frequency spectrum of the input image (video signal) DIN, the intensity of the portion included in the low frequency component side region RL1 and the high frequency component side region RH1 is weakened. Accordingly, the intermediate image D111 is obtained by removing the spectrum SP1 that is the aliasing component from the high frequency component of the input image (video signal) DIN. That is, the intermediate image generating unit 111 has an effect of generating the intermediate image D111 by removing the spectrum SP1 that is the aliasing component from the high frequency component of the input image (video signal) DIN.

  FIGS. 11A to 11C are diagrams showing the operation and effect of the intermediate image generation unit 112. FIG. 11A shows the frequency spectrum of the nonlinear processed image D112A, and FIG. 11B shows the high frequency component. FIG. 11C shows the frequency response of the image 112B, and FIG. 11C shows the frequency spectrum of the image D112B. In FIG. 11, for the same reason as in FIG. 10, the frequency spectrum or the intensity of the frequency response is shown only in the range where the spatial frequency is 0 or more.

  As will be described later, in the nonlinear processed image D112A, a high frequency component corresponding to the region RH2 on the high frequency component side is generated. FIG. 11A is a diagram schematically showing the state. The image D112B is generated when the nonlinear processed image D112A passes through the high frequency component image generation means 112B. The high frequency component image generation means 112B is composed of a high pass filter, and the frequency response becomes higher as the frequency becomes higher as shown in FIG. Therefore, the frequency spectrum of the image D112B is obtained by removing the component corresponding to the region RL2 on the low frequency component side from the frequency spectrum of the nonlinear processed image D112A as shown in FIG. In other words, the nonlinear processing unit 112A has an effect of generating a high frequency component corresponding to the region RH2 on the high frequency component side, and the high frequency component image generating unit 112B has only the high frequency component generated by the nonlinear processing unit 112A. There is an effect to take out.

  The above operations and effects will be described in more detail.

  12 and 13 are diagrams showing signals obtained when sampling the step edge. 12A shows the step edge and the sampling interval S1, FIG. 12B shows a signal obtained when the step edge is sampled at the sampling interval S1, and FIG. 12C shows FIG. It represents the high frequency component of the signal represented in (B). On the other hand, FIG. 13A shows a sampling interval S2 which is wider than the step edge and the sampling interval S1, and FIG. 13B shows a signal obtained when the step edge is sampled at the sampling interval S2. FIG. 13C shows high frequency components of the signal shown in FIG. In the following description, it is assumed that the length of the sampling interval S2 is twice the length of the sampling interval S1.

  As shown in FIGS. 12C and 13C, the center of the step edge appears as a zero cross point Z in the signal representing the high frequency component. In addition, the slope of the signal representing the high frequency component near the zero cross point Z becomes steeper as the sampling interval is short, and the position of the point giving the local maximum and minimum values near the zero cross point Z is also The shorter the sampling interval, the closer to the zero cross point Z.

  That is, even if the sampling interval changes, the position of the zero crossing point of the signal representing the high frequency component does not change near the edge, but the slope of the high frequency component near the edge decreases as the sampling interval decreases (or the resolution increases). The position of the point that gives the local maximum and minimum values approaches the zero-cross point.

  FIG. 14 is a diagram showing the operation and effect when the signal obtained by sampling the step edge at the sampling interval S1 is doubled and then input to the video recording apparatus according to the present invention. The operation and effect of the intermediate image generation means 112 are shown. As described above, since the processing inside the intermediate image generation unit 111 and the intermediate image generation unit 112 is performed in each of the horizontal direction and the vertical direction, the processing is performed one-dimensionally. Therefore, in FIG. 14, the contents of processing are expressed using a one-dimensional signal.

  FIG. 14A shows a signal obtained by sampling the step edge at the sampling interval S2 as in FIG. 13B. FIG. 14B is a signal obtained by enlarging the signal shown in FIG. 14A twice. That is, when the original image DORG includes an edge as shown in FIG. 14A, a signal as shown in FIG. 14B is input as the input image (video signal) DIN. Note that when the signal is doubled, the sampling interval is half that before the expansion, and therefore the sampling interval of the signal shown in FIG. 14B is the same as the sampling interval S1 in FIG. In FIG. 14A, the position represented by the coordinate P3 is the boundary portion on the low luminance side of the edge signal, and the position represented by the coordinate P4 is the boundary on the high luminance side of the edge signal.

  FIG. 14C shows a signal representing the high frequency component of the signal shown in FIG. 14B, that is, a signal corresponding to the image D111A output from the high frequency component image generating unit 111A. Note that the image D111A is obtained by extracting a high frequency component of the input image (video signal) DIN, and therefore includes an aliasing component.

  FIG. 14D shows a signal representing the low frequency component of the signal shown in FIG. 14C, that is, a signal corresponding to the image D111B output from the low frequency component image generation means 111B. Since the image D111B is output as the intermediate image D111 as described above, FIG. 14D corresponds to the intermediate image D111. As shown in FIG. 14D, the local minimum value in the vicinity of the zero cross point Z in the intermediate image D111 appears at the coordinate P3, and the local maximum value appears at the coordinate P4. The situation is shown in FIG. The step edge coincides with the high frequency component extracted from the signal sampled at the sampling interval S2. In addition, the aliasing component included in the image D111A is removed by a low-pass filter process performed by the low-frequency component image generation unit 111B.

  FIG. 14E shows an output signal when the signal shown in FIG. 14D is input to the nonlinear processing means 112A, that is, an image output from the nonlinear processing means 112A when the intermediate image D111 is input. D112A is shown. In the nonlinear processing means 112A, the signal values of the coordinates P1 and P2 before and after the zero cross point Z are amplified. Therefore, as shown in FIG. 14E, in the image D112A, the magnitude of the signal value at the coordinates P1 and P2 is larger than the other values, and the position where the local minimum value appears near the zero cross point Z is the coordinate. The position where the local maximum value appears at the coordinate P1 closer to the zero cross point Z from P3 changes from the coordinate P4 to the coordinate P1 closer to the zero cross point Z. This means that the high frequency component is generated by the nonlinear processing of amplifying the pixel values around the zero cross point Z in the nonlinear processing means 112A. In this way, it is possible to generate a high-frequency component by adaptively changing the amplification factor for each pixel or appropriately changing the content of processing according to the pixel. That is, the nonlinear processing means 112A has an effect of generating a high frequency component not included in the intermediate image D111, that is, a high frequency component corresponding to the region RH2 on the high frequency component side shown in FIG.

  FIG. 14F shows a signal representing the high frequency component of the signal shown in FIG. 14E, that is, a signal corresponding to the image D112B output from the high frequency component image generating means 112B. As shown in FIG. 14F, the local minimum value in the vicinity of the zero cross point Z in the image D112B appears at the coordinate P1, the maximum value appears at the coordinate P2, and this is shown by the step edge shown in FIG. This coincides with the high frequency component extracted from the signal sampled at the sampling interval S1. This means that the high frequency component generated by the nonlinear processing means 112A is taken out by the high frequency component image generating means 112B and output as an image D112B. Further, it can be said that the extracted image D112B is a signal including a frequency component corresponding to the sampling interval S1. In other words, the high frequency component image generation unit 112B has an effect of extracting only the high frequency component generated by the nonlinear processing unit 112A.

  The adding unit 112C adds the intermediate image D111 and the image D112B to generate an image D112C. As described above, the intermediate image D111 is obtained by removing the aliasing component from the high frequency component of the input image (video signal) DIN, and as shown in FIG. 10E, the high frequency component in the vicinity of the Nyquist frequency of the original image DORG. It corresponds to. As described with reference to FIG. 9D, since the spectral intensity in the vicinity of the Nyquist frequency of the original picture DORG is weakened by the enlargement processing means 13, the intermediate picture D111 is added to compensate for the spectral intensity weakened by the enlargement process. be able to. Further, since the aliasing component is removed from the intermediate image D111, a false signal such as overshoot, jaggy, or ringing is not emphasized. On the other hand, the image D112B is a high frequency component corresponding to the sampling interval S1. Therefore, by adding the image D112C, it is possible to provide a high-frequency component in a band equal to or higher than the Nyquist frequency of the original image DORG, so that the resolution of the image can be increased. Therefore, by adding the image D112C obtained by adding the intermediate image D111 and the image D112B to the input image (video signal) DIN, it becomes possible to add a high frequency component without enhancing the aliasing component, and to improve the resolution of the image. It becomes possible to raise.

  In the adding means 113, the image D112C is added as an intermediate image D112 to the input image (video signal) DIN. Therefore, it is possible to add a high frequency component while suppressing an increase in overshoot, jaggy, ringing, or the like due to the aliasing component, thereby enhancing the resolution of the image.

  Further, in the video recording apparatus according to the present invention, the intermediate image generation unit 111 and the intermediate image generation unit 112 perform the processing related to the horizontal direction of the image and the processing related to the vertical direction in parallel, so only the horizontal direction of the image or the vertical direction. The above effects can be obtained not only in the direction but also in any direction.

  In the video recording apparatus according to the present invention, the input image (video signal) DIN is in the vicinity of the Nyquist frequency ± Fn / 2 of the original picture DORG (or a specific frequency band) in the frequency band extending from the origin to Fn in the frequency space. Based on the components possessed, the image D112B corresponding to the high frequency components near the Nyquist frequency ± Fn is generated. Therefore, even if the frequency component near the Nyquist frequency ± Fn is lost in the input image (video signal) DIN for some reason, the frequency component near the Nyquist frequency ± Fn can be given by the image D112B.

  Next, the compression rate in the compression processing unit 12 and the signal bands extracted by the high frequency component image generation unit 111A, the low frequency component image generation unit 111B, and the high frequency component image generation unit 112B will be described with reference to FIGS. To do.

  When image compression is performed on the input image (video signal) DIN image to increase the compression ratio, the frequency spectrum is on the low frequency component side as shown by the dotted line portion with respect to the solid line portion in FIG. . In order to cope with the above, the frequency response of the high frequency component image generation unit 111A is set to a low frequency component as shown by a dotted line portion with respect to the solid line portion in FIG. Is a low frequency component as shown by a dotted line portion with respect to a solid line portion in FIG. At this time, the frequency response of the intermediate image generating unit 111 is the high frequency component image generating unit 111A in the intermediate image generating unit 111 for the frequency component in the region RL1 on the low frequency component side shown in FIG. The frequency components in the high frequency component side region RH1 are weakened by the low frequency component image generation unit 111B in the intermediate image generation unit 111, and therefore, as shown by the dotted line portions in FIGS. 15B and 15C. In the case of a frequency response, the frequency response of the intermediate image generating unit 111 has a peak on the lower frequency component side in the region RM1 in FIG. In this case, the frequency spectrum of the intermediate image D111 is on the low frequency component side as shown in FIG.

  If the frequency response of the high frequency component image generating means 112B in the intermediate image generating means 112 is a low frequency component as shown by the dotted line portion with respect to the solid line portion in FIG. 16B, the frequency spectrum of the image D112B is as shown in FIG. The region RH2 on the high frequency component side in (C) is on the low frequency component side. As a result, when the compression ratio is increased, the frequency spectrum of the input image (video signal) DIN is closer to the lower frequency component, and the image generating unit is changed to extract a lower frequency component. It can respond.

  Therefore, when the compression ratio is increased, the frequency component extracted in each of the image generation means can be changed to a low frequency, such as receiving the control signal CMP according to the compression ratio, the high frequency component image generation means 111A, the low frequency By changing the frequency components extracted by the component image generation unit 111B and the high frequency component image generation unit 112B, it is possible to automatically adjust the enhancement processing according to the size of the compression rate.

  In the above description, the control signal CMP according to the compression rate is output in the compression processing unit that performs image compression. However, as shown in FIG. When the decompression processing means 15b performs the decompression processing in the case of reproduction by the above, the compression rate is comprehensively calculated by a compression technique such as variable length coding, DCT, quantization, etc., and the decompression processing means 15b controls according to the compression rate. The configuration may be such that the signal CMP is output. Although not described in detail in the above description, when the control signal CMP is output from the compression processing means 12, the time required for processing in the compression processing means 12, the access means 14, and the expansion processing means 15 is compressed for the video signal. It is necessary to delay the control signal CMP in the processing means 12. For example, the expansion processing unit 15b of FIG. 7 is used instead of the expansion processing unit 15 in the video recording / reproducing apparatus, and the control signal CMP is output from the expansion processing unit 15b to the signal processing unit 11 instead of the compression processing unit 12. According to the configuration, the control signal CMP output from the expansion processing unit 15b is already delayed together with the video signal, and therefore it is not necessary to delay in the expansion processing unit 15b.

  In the above description, in order to change the degree of enhancement processing according to the compression rate, the high frequency component image generation unit 111A, the low frequency component image generation unit 111, and the like are extracted based on the value of the control signal CMP from the compression processing unit 12. However, instead of the adding means 112C in the signal processing means 11b, a weighted adding means 112D as shown in FIG. 17 is provided, and according to the value of the control signal CMP from the compression processing section 12, A configuration may be adopted in which the degree of enhancement processing is weakened by making the multiplication value multiplied by the nonlinear processing means output signal D112B smaller than the multiplication value multiplied by the intermediate image D111.

Embodiment 2. FIG.
FIG. 18 is a diagram showing a flow of a video recording / playback method according to the second embodiment of the present invention. The video recording / playback method according to the second embodiment of the present invention includes a compression processing step ST1, a media access step ST2, and an expansion processing step. It consists of ST3 and signal processing step ST4.

  As shown in FIG. 19, the signal processing step ST4 includes an intermediate image generation step ST4A, an intermediate image generation step ST4B, and an addition step ST4C. The intermediate image generation step ST4A is a high frequency component image generation step ST4A1, a low frequency component image generation step. From ST4A2, the intermediate image generation step ST4B is realized by a non-linear processing step ST4B1, a high frequency component image generation step ST4B2, and an addition step ST4B3.

  As shown in FIG. 20, the high frequency component image generation step ST4A1 includes a horizontal high frequency component passing step ST4A1h and a vertical high frequency component passing step ST4A1v.

  As shown in FIG. 21, the low frequency component image generation step ST4A2 includes a horizontal direction low frequency component passing step ST4A2h and a vertical direction low frequency component passing step ST4A2v.

  As shown in FIG. 22, the nonlinear processing step ST4B1 includes a horizontal nonlinear processing step ST4B1h and a vertical nonlinear processing step ST4B1v.

  As shown in FIG. 23, the high frequency component image generation step ST4B2 includes a horizontal high frequency component passing step ST4B2h and a vertical high frequency component passing step ST4B2v.

  As shown in FIG. 24, the horizontal direction nonlinear processing step ST4B1h includes a zero-cross determination step ST4B11h and a signal amplification step ST4B12h. The vertical direction nonlinear processing step ST4B1v includes a zero-cross determination step ST4B11v and a signal amplification step ST4B12v as shown in FIG. Including.

  First, the operation of the intermediate image generation step ST4A will be described according to the flow of FIGS. 19, 20 and 21.

  In the high frequency component image generation step ST4A1, the following processing is performed on the input image (video signal) DIN input in the image input step (not shown). First, in the horizontal high-frequency component image generation step ST4A1h, an image D111Ah obtained by extracting the high-frequency component in the horizontal direction from the input image (video signal) DIN is generated by the high-pass filter processing in the horizontal direction. In the vertical high-frequency component image step ST4A1v, an image D111Av obtained by extracting the high-frequency component in the vertical direction from the input image (video signal) DIN is generated by the high-pass filter processing in the vertical direction. That is, the high frequency component image generation step ST4A1 performs the same processing as the high frequency component image generation unit 111A, and generates an image D111A composed of the image D111Ah and the image D111Av from the input image (video signal) DIN. This operation is equivalent to the high frequency component image generation unit 111A.

  In the low frequency component image generation step ST4A2, the following processing is performed on the image D111A. First, in the horizontal low-frequency component image generation step ST4A2h, an image D111Bh obtained by extracting the horizontal low-frequency component from the image D111Ah is generated by horizontal low-pass filter processing. In the vertical direction low frequency component image generation step ST4A2v, an image D111Bv obtained by extracting the low frequency component in the vertical direction from the image D111Av is generated by the low pass filter processing in the vertical direction. That is, the low frequency component image generation step ST4A2 performs the same processing as the low frequency component image generation unit 111B, and generates an image D111B composed of the image D111Bh and the image D111Bv from the image D111A. This operation is equivalent to the low-frequency component image generation unit 111B.

  The above is the operation of the intermediate image generation step ST4A. In the intermediate image generation step ST4A, the image D111Bh is set as the image D111h, the image D111Bv is set as the image D111v, and the intermediate image D111 including the image D111h and the image D111v is output. The above operation is equivalent to that of the intermediate image generating unit 111.

  Next, the operation of the intermediate image processing step ST4B will be described according to the flow of FIGS.

  First, in the nonlinear processing step ST4B1, the following processing is performed on the intermediate image D111.

  First, in the horizontal non-linear processing step ST4B1h, an image D112Ah is generated from the image D111h by processing according to the flow shown in FIG. The processing in the flow shown in FIG. 24 is as follows. First, in the zero cross determination step ST4B11h, a change in the pixel value in the image D111h is confirmed along the horizontal direction. A location where the pixel value changes from a positive value to a negative value or from a negative value to a positive value is regarded as a zero cross point, and the pixels located on the left and right of the zero cross point are notified to the signal amplification step ST4B12h. In the signal amplification step ST4B12h, for the image D111h, the pixel value of the pixel notified to be positioned on the left and right of the zero cross point is amplified, and the image is output as the image D112Ah. That is, the nonlinear processing step ST4B1h performs the same processing as the horizontal nonlinear processing means 112Ah on the image D111h to generate the image D112Ah.

  Next, in the vertical non-linear processing step ST4B1v, an image D112Av is generated from the image D111v by processing according to the flow shown in FIG. The processing in the flow shown in FIG. 25 is as follows. First, in the zero cross determination step ST4B11v, a change in pixel value in the image D111v is confirmed along the vertical direction. Then, a portion where the pixel value changes from a positive value to a negative value or from a negative value to a positive value is regarded as a zero cross point, and the pixels located above and below the zero cross point are notified to the signal amplification step ST4B12v. In the signal amplification step ST4B12v, the pixel value of the pixel notified to be positioned above and below the zero cross point is amplified for the image D111v, and the image is output as the image D112Av. That is, the nonlinear processing step ST4B12Av performs the same processing as the vertical nonlinear processing means 112Av on the image D111v to generate an image D112Av.

  The above is the operation of the non-linear processing step ST4B1, and the non-linear processing step ST4B1 generates an image D112A composed of the image D112Ah and the image D112Av. The operation is equivalent to the nonlinear processing means 112A.

  Next, in the high frequency component image generation step ST4B2, the following processing is performed on the image D112A.

  First, in the horizontal high-frequency component image generation step ST4B2h, an image D112Bh obtained by performing a horizontal high-pass filter process on the image D112Ah is generated. That is, the horizontal high frequency component image generation step ST4B2h performs the same processing as the horizontal high frequency component image generation means 112Bh.

  Next, in the vertical direction high-frequency component image generation step ST4B2v, an image D112Bv obtained by performing vertical high-pass filter processing on the image D112Av is generated. That is, the vertical high frequency component image generation step ST4B2v performs the same processing as the vertical high frequency component image generation means 112Bv.

  The above is the operation of the high frequency component image generation step ST4B2, and the high frequency component image generation step ST4B2 generates an image D112B composed of the image D112Bh and the image D112Bv. The operation is the same as that of the high frequency component image generation means 112B.

  In addition step ST4B3, the image D112B and the intermediate image D111 are added to generate an image D112C.

  The above is the operation of the intermediate image processing step ST4B. The intermediate image processing step ST4B outputs the image D112C as the intermediate image D112. This operation is equivalent to the intermediate image processing means 112.

  In addition step ST4C, the input image (video signal) DIN and the intermediate image D112 are added to generate an output image DOUT. The output image DOUT is output as the final output image (video signal) of the image processing method according to the present invention. That is, the operation of the adding step ST4C is equivalent to the operation of the adding means 113.

  The above is the operation of the video recording / reproducing method of the present invention.

  As is apparent from the description, the operation of the video recording / reproducing method according to the present invention is equivalent to the video recording / reproducing apparatus according to the first embodiment of the present invention. Therefore, the video recording / playback method according to the present invention has the same effects as the video recording / playback apparatus according to the first embodiment of the present invention.

1 video recording and playback device, 2a input terminal, 2b output terminal, 3 recording media,
11a, 11b Signal processing means, 12 access means, 13 enlargement processing means, 15 expansion processing means.

Claims (7)

Compression processing means for performing an image compression process on the input signal and outputting a control signal that changes in accordance with the compression rate;
Access means for recording compressed video data on a recording medium and reading the video data from the recording medium ;
Signal processing means for reproducing recorded video data from a recording medium via the access means, and performing signal processing on a reproduction signal subjected to decompression processing;
The signal processing means includes a first intermediate image generating means for generating a first intermediate image obtained by extracting a component in the vicinity of a specific frequency band of the input image, and a second intermediate image obtained by processing the first intermediate image. a second intermediate image generating means for generating, and a first addition means for adding the second intermediate image and the input image,
The first intermediate image generation unit generates a first high frequency component image obtained by extracting only the high frequency component of the input image, and extracts a frequency component of a signal to be extracted according to a control signal from the compression processing unit. Only the first high frequency component image generation means to be changed and the low frequency component of the first high frequency component image are extracted, and the frequency component of the signal to be extracted is changed according to the control signal from the compression processing means. and a frequency component image generating means,
The second intermediate image generation means generates a nonlinear processed image obtained by amplifying each pixel value of the first intermediate image with an amplification factor changed according to the pixel; A second high-frequency component image generation unit that generates a second high-frequency component image obtained by extracting only the frequency component, and changes a frequency component of a signal to be extracted according to a control signal from the compression processing unit; A second adding means for adding the intermediate image of 1 and the second high-frequency component image, and changing a signal band setting to be extracted according to a value of the control signal;
The non-linear processing means generates a non-linear processed image obtained by amplifying each pixel value adjacent to a zero cross point of the first intermediate image with an amplification factor greater than 1. The first high frequency component image generation means includes:
First horizontal high-frequency component image generation means for generating a first horizontal high-frequency component image obtained by extracting a high-frequency component using pixels existing in the horizontal direction of each pixel of the input image;
First vertical high-frequency component image generating means for generating a first vertical high-frequency component image obtained by extracting a high-frequency component using pixels existing in the vertical direction of each pixel of the input image; ,
The low frequency component image generation means includes
Horizontal low-frequency component image generation means for generating a first horizontal intermediate image obtained by extracting only the low-frequency component of the first horizontal high-frequency component image;
2. The video according to claim 1, further comprising: a vertical low frequency component image generating means for generating a first vertical intermediate image obtained by extracting only a low frequency component of the first vertical high frequency component image. Recording / playback device. The nonlinear processing means includes:
Horizontal non-linear processing means for generating a horizontal non-linear processed image obtained by amplifying each pixel value adjacent to the zero-cross point of the first horizontal intermediate image at an amplification factor greater than 1,
Vertical non-linear processing means for generating a vertical non-linear processing image obtained by amplifying each pixel value adjacent to the zero cross point of the first vertical intermediate image with an amplification factor greater than 1.
The second high frequency component image generating means includes:
Second horizontal high frequency component image generation means for generating a second horizontal high frequency component image obtained by extracting only the high frequency component of the horizontal nonlinear processed image;
According to claim 2, characterized in that it comprises a second vertical high-frequency component image generating means for generating a second vertical high-frequency component image obtained by extracting only the high-frequency component of the vertical nonlinear processed image Video recording / playback device. The horizontal non-linear processing means includes:
Horizontal zero-cross point determining means for determining a point where the pixel value of the first horizontal intermediate image changes from positive to negative or from negative to positive as a zero-cross point;
Horizontal signal amplification means for determining an amplification factor for each pixel of the first horizontal intermediate image according to a determination result of the horizontal zero-cross point determination means;
The vertical nonlinear processing means includes:
Vertical zero cross point determination means for determining, as a zero cross point, a location where the pixel value of the first vertical intermediate image changes from positive to negative or from negative to positive;
4. The video recording according to claim 3, further comprising vertical signal amplification means for determining an amplification factor for each pixel of the first vertical intermediate image in accordance with a determination result of the vertical zero-cross point determination means. Playback device. Access means for playing back video data compressed and recorded on a recording medium;
Decompression processing means for outputting a control signal that changes in accordance with the compression rate of the video data when performing the decompression processing of the video data;
Signal processing means for performing signal processing on the reproduction signal;
The signal processing means includes a first intermediate image generating means for generating a first intermediate image obtained by extracting a component in the vicinity of a specific frequency band of the input image, and a second intermediate image obtained by processing the first intermediate image. a second intermediate image generating means for generating, and a first addition means for adding the second intermediate image and the input image,
Before SL first intermediate image generating means generates the first high-frequency component image by extracting only the high-frequency component of the input image, the frequency components of the signal to be extracted in accordance with a control signal from said decompression means Only the first high frequency component image generating means for changing the image and the low frequency component of the first high frequency component image are extracted, and the frequency component of the signal to be extracted is changed according to the control signal from the expansion processing means and a low-frequency component image generating means,
The second intermediate image generation means extracts nonlinear processing means for generating a nonlinear processed image by changing the content of processing according to the pixels of the first intermediate image, and extracts only the high frequency component of the nonlinear processed image. A second high-frequency component image generating means for generating a second high-frequency component image and changing a frequency component of a signal to be extracted according to a control signal from the decompression processing means; the first intermediate image; video reproducing apparatus characterized by chromatic and second adding means for adding the second high-frequency component image. In a video recording / reproducing method in which an image input signal is subjected to image compression processing in a compression processing step and signal processing is performed in the signal processing step.
The signal processing step comprises:
An intermediate image generating step of extracting a component in the vicinity of a specific frequency band of the image input signal to generate a first intermediate image;
An intermediate image generating step of generating a second intermediate image obtained by adding a high frequency component generated by applying a non-linear process to the first intermediate image;
Consists adding means generating an movies image output signal by adding the second intermediate image and the image input image,
The intermediate image generation step includes a non-linear processing step of changing a content of processing according to a pixel of the first intermediate image,
The degree of enhancement processing by adjusting the intermediate image generated in the intermediate image generating step for generating the first intermediate image and the intermediate image generating step for generating the second intermediate image according to the compression rate in the compression processing step A video recording / playback method characterized by playing back a video signal in which a change is made.   Access means for playing back video data compressed and recorded on a recording medium;
Decompression processing means for outputting a control signal that changes in accordance with the compression rate of the video data when the video data is decompressed;
Signal processing means for performing signal processing on the reproduction signal; and
Have
  The signal processing means includes a first intermediate image generating means for generating a first intermediate image obtained by extracting a component in the vicinity of a specific frequency band of the input image, and a second intermediate image obtained by processing the first intermediate image. Second intermediate image generation means for generating the input image, and first addition means for adding the input image and the second intermediate image,
  The first intermediate image generation unit generates a first high frequency component image obtained by extracting only the high frequency component of the input image, and extracts a frequency component of a signal to be extracted according to a control signal from the expansion processing unit. First high frequency component image generating means to be changed, and a low frequency for taking out a low frequency component of the first high frequency component image and changing a frequency component of a signal to be extracted according to a control signal from the expansion processing means Component image generation means,
  The second intermediate image generation unit extracts a non-linear processing unit that generates a non-linear processing image by changing processing contents according to the pixels of the first intermediate image, and extracts a high frequency component of the non-linear processing image A second high-frequency component image generating means for generating a second high-frequency component image and changing a frequency component of a signal to be extracted according to a control signal from the decompression processing means; the first intermediate image; And a second adding means for adding the second high-frequency component image.

Images