JP2011044925A - Video reproducing apparatus, apparatus and method for recording and reproducing video - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent reduction in a degree of highlight processing when a magnification factor is enlarged in a video recording and reproducing apparatus for magnifying and recording or reproducing a video image. <P>SOLUTION: A video input signal from an input terminal 3a is data-compressed by a compression processing means 13 and input to an access means 14. Data are written into or read from recording media 2 by the access means 14. A reproducing video signal read from the recording media 2 and expansion-processed by an expansion processing means 15 is magnification-processed by a magnification processing part 12a and a return component with the magnification processing is removed by a signal processing means 11b, thereby outputting from an output terminal 3b a video signal on which signal processing has been performed for adding a high-frequency component lost by data compression or the like. In this case, the high-frequency component in the signal processing means 11b is controlled by a control signal corresponding to a magnification factor output from the magnification processing part 12b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a video playback device and video recording / playback device that outputs a video signal that has been subjected to enhancement processing on a video signal that has been played back from a recording medium, or a video signal that has been subjected to enhancement processing on a video input signal. In particular, when a video signal is enlarged and recorded or reproduced, a high frequency component lost by the enlargement process is generated and added to the enlarged video signal. Video enhancement processing is performed so as to obtain an output signal with high resolution.

  Generally, video is displayed after appropriately performing signal processing on the 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, the enhancement processing is inappropriate or insufficient depending on the input image. It was impossible to obtain an output image with high image quality.

  For example, when an image that has undergone enlargement processing is input as an input image (video input signal), a component in which a part of the frequency spectrum of the image before enlargement processing is folded on the high frequency component side of the frequency spectrum of the input image (Folding component) appears. 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.

  When an image subjected to noise processing is input as an input image, the frequency spectrum on the high frequency component side is lost due to noise processing. Therefore, even if an attempt is made to extract a high frequency component, it cannot be extracted, and image enhancement processing may not be performed sufficiently.

  The present invention has been made to solve the above-described problems. In the case of a signal format in which the output signal is larger in the number of horizontal pixels and lines than the recorded signal, or a part of the image is enlarged. An object is to enhance the resolution of an image even when high frequency components of the image are lost due to circumstances.

The video playback apparatus and video recording / playback apparatus according to the present invention play back image data recorded on a recording medium, output the playback image data, perform decompression processing on the playback image data, and playback video signal An expansion processing means for outputting the reproduction video signal, an enlargement processing means for performing an image enlargement process on the reproduced video signal and outputting an image enlargement video signal and an enlargement ratio signal indicating an image enlargement ratio, and a non-linear process on the image enlargement video signal And a signal processing means for generating a video output signal to which the high frequency component generated by applying is added,
The signal processing means extracts a signal in a frequency band set based on the enlargement ratio signal from the image enlargement signal and generates a first intermediate image, and the first intermediate image generation means, A signal in a frequency band set based on the magnification signal is extracted from a high frequency component generated by performing non-linear processing on the intermediate image, and added to the first intermediate image to generate a second intermediate image. And a second intermediate image generating means for adding the image input image and the second intermediate image to generate the video output signal.

  According to the present invention, the first intermediate image generating means extracts the high frequency component of the image enlarged video signal, and further extracts the low frequency component in the horizontal direction and the vertical direction to remove the aliasing component. An image is generated, and in the second intermediate image generation means, a high frequency component is generated by performing non-linear processing on the first intermediate image, and further, a high frequency component and a low frequency component set based on the enlargement ratio are generated. Since the frequency band component is extracted and added to the first intermediate image to generate the second intermediate image, and the second intermediate image is added to the image enlarged video signal. If the output signal is a signal format with a large number of horizontal pixels and lines, or if the high frequency component of the image is lost due to enlargement of a part of the image, the high frequency component of the image is sufficiently given Bets can be, it is possible to increase the resolution of the image.

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 a block diagram of the expansion process means 12a, 12b. It is another block diagram of the video recording / reproducing apparatus by Embodiment 1 of this invention. It is operation | movement explanatory drawing of the expansion process means 12b. It is operation | movement explanatory drawing of the expansion process means 12b. FIG. 7 is an operation explanatory diagram of first intermediate image generation means 111. FIG. 10 is an operation explanatory diagram of the second intermediate image processing means 112. 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. 6 is an operation explanatory diagram of first intermediate image generation means 111 and second intermediate image processing means 112. FIG. 7 is an operation explanatory diagram of first intermediate image generation means 111. FIG. 10 is an operation explanatory diagram of the second intermediate image generating means 112. 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 ST5 of FIG. It is a flowchart which shows the process in high frequency component image generation step ST5A1 of FIG. It is a flowchart which shows the process in low frequency component image generation step ST5A2 of FIG. It is a flowchart which shows the process in nonlinear process step ST5B1 of FIG. It is a flowchart which shows the process in high frequency component image generation step ST5B2 of FIG. It is a flowchart which shows the process in horizontal direction nonlinear process step ST5B1h of FIG. It is a flowchart which shows the process in the vertical direction nonlinear process step ST5B1v 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.

  In the video recording / reproducing apparatus 1, the video input signal is compressed in the compression processing unit 13 by a high-efficiency irreversible compression method such as MPEG-2, and then recorded by the access means 14 to be recorded on a recording medium such as an optical disk. 2 is written. The compressed data read from the recording medium 2 by the access unit 14 is restored to a video reproduction signal by a video signal reproduction process such as data expansion by the expansion processing unit 15, and then the image is enlarged by the expansion processing unit 12 b. Are input to the signal processing means 11b. In the signal processing means 11b, signal processing is performed to generate and add high frequency components to enhance the resolution of the image. It is assumed that the enlargement processing means 12b outputs a control signal CTL corresponding to the enlargement ratio in addition to the enlarged video signal subjected to signal processing and sends it to the signal processing means 11b.

  FIG. 2 is a diagram showing the configuration of the signal processing means 11b in FIG. The signal processing unit 11b generates a first intermediate image generation unit 111 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 generates an intermediate image D112 obtained by performing processing described later on the image D111. 2, an intermediate image generation unit 112 and an addition unit 113 that adds the input signal DIN and the intermediate image D112. The addition unit 113 adds the input signal DIN and the intermediate image D112 and outputs the result as an output signal DOUT.

  The first intermediate image generation unit 111 generates a high-frequency component image generation unit 111A that generates an image D111A in which only a high-frequency component is extracted from the input signal DIN, and a low-frequency that generates an image D111B in which only a low-frequency component of the image D111A is extracted. It consists of component image generation means 111B. From the first intermediate image generating unit 111, the image D111B is output as the intermediate image D111.

  The second intermediate image generating 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 that outputs an image D112B obtained by extracting only the high-frequency component of the image D112A. The image generating unit 112B includes an adding unit 112C that outputs an image D112C obtained by adding the intermediate image D111 and the image D112B. The second intermediate image generating unit 112 outputs the image D112C 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 CTL from the enlargement processing unit 12b and set a 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 3a is compressed in the compression processing unit 13 by a high-efficiency irreversible compression method such as MPEG-2, and then input to the access means 14. The access means 14 A video reproduction signal is output by writing and reading data to and from the recording medium 2. This video reproduction signal is output as an enlarged video signal having a aliasing component by the enlargement processing by the enlargement processing means 12b. In the signal processing unit 11b, by performing signal processing such as adding a high frequency component from which the aliasing component of the enlarged video signal is removed and a high frequency component in a band equal to or higher than the Nyquist frequency of the enlarged video signal to the enlarged video signal, A video signal that enhances the sense of resolution of the image is output by compensating for the high-frequency component that has been lost due to data compression accompanying recording.

  The signal processing means 11b will be described in detail below. The signal processing unit 11b generates a first intermediate image generation unit 111 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 generates an intermediate image D112 obtained by performing processing described later on the image D111. Second intermediate image generation means 112, and addition means 113 for adding the input signal DIN, the intermediate image D111, and the intermediate image D112.

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

  The first intermediate image generation unit 111 generates an image D111A in which only the high frequency component of the input image DIN is extracted 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. The horizontal direction high frequency component image generation unit 111Ah and the vertical direction high frequency component image generation unit 111Av change the signal band setting to be extracted depending on the value of the control signal CTL from the enlargement processing unit 12b.

  Next, the first 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. The first intermediate image generating 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 enlarged processing units, like 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 CTL from 12b.

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

  First, the second intermediate image generating unit 112 generates an image D112A obtained by performing nonlinear processing described later on the intermediate image D111 in the nonlinear processing unit 112A. Nonlinear processing is performed for each of the horizontal direction and the vertical direction. That is, the non-linear processing means 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 picture 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 specifies 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. In the non-linear processing means, the high frequency component is generated by adaptively changing the amplification factor for each pixel or appropriately changing the content of the processing according to the pixel. Details will be described later.

  Next, the second intermediate image generation unit 112 generates an image D112B in which only the high frequency component of the image D112A is extracted 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 unit 112Bh and the vertical direction high frequency component image generation unit 112Bv are respectively enlarged processing units, like 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 CTL from 12b.

  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 second intermediate image generating unit 112 outputs the image D112C as the intermediate image D112. The intermediate image D112 is a high-frequency component from which the aliasing component is removed, and adding this makes it possible to enhance the resolution of the image without enhancing the aliasing component, details of which will be described later.

  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. Then, the output image DOUT is output as an output image.

  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 enlargement processing unit 12b outputs an enlarged image of the reproduction signal reproduced from the recording medium 2 when the image size of the reproduction signal reproduced from the recording medium 2 is smaller than the image size output from the terminal 2b. Here, a bicubic method or the like can be used as means for enlarging the image.

  The signal processing means 11b in the present invention outputs an image D11b obtained by performing the above-described processing on the input image D12b.

  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 12b will be described first.

  FIG. 5 is a diagram showing the configuration and operation of the enlargement processing means 12b. The enlargement processing means 12b includes a horizontal zero insertion means 121, a horizontal low frequency component passing means 122, a vertical zero insertion means 123, and a vertical low frequency. The component passing means 124 is included. The horizontal zero insertion means 121 generates an image D121 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 122 generates an image D122 obtained by extracting only the low frequency component of the image D121 by low-pass filter processing. The vertical direction zero insertion unit 123 generates an image D123 in which pixels having a pixel value 0 in the vertical direction of the image D122 are appropriately inserted. The vertical low frequency component passing means 124 generates an image D124 obtained by extracting only the low frequency component of the image D123. The image D124 is output from the enlargement processing means as an image obtained by doubling the original image DORG in both the horizontal and vertical directions.

  7A and 7B are diagrams for explaining the operation of the enlargement processing unit 12b in detail. FIG. 7A shows the original image DORG, FIG. 7B shows the image D121, FIG. 7C shows the image D122, and FIG. 7 (D) represents the image D123, and FIG. 7 (E) represents the image D124. 7A to 7E, 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 121 inserts one pixel having a pixel value of 0 for each pixel in the horizontal direction into the original image DORG shown in FIG. 7A, and creates an image D121 shown in FIG. 7B. Generate. The horizontal low-frequency component passage unit 122 performs low-pass filter processing on the image D121 shown in FIG. 7B to generate an image D122 shown in FIG. The vertical zero insertion means 123 inserts one pixel having a pixel value of 0 for each pixel in the vertical direction into the image D122 shown in FIG. 7C, and the image D123 shown in FIG. Generate. The vertical low frequency component passing means 124 performs a low pass filter process on the image D123 shown in FIG. 7D to generate an image D124 shown in FIG. Through the above processing, an image D124 is generated in which the original image DORG is doubled in both the horizontal and vertical directions.

  FIG. 8 shows the effect of processing by the enlargement processing means 12b on the frequency space. FIG. 8A shows the frequency spectrum of the original picture DORG, FIG. 8B shows the frequency spectrum of the image D121, and FIG. ) Represents the frequency response of the horizontal direction frequency component passing means 122, and FIG. 8D represents the frequency spectrum of the image D122. In FIG. 8, the horizontal axis is 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. Note that the number of pixels of the original image DORG is half that of the input image DIN. In other words, the sampling interval of the original image DORG is twice the sampling interval of the input image DIN. Therefore, the Nyquist frequency of the original image DORG is half of the Nyquist frequency of the input image DIN, that is, Fn / 2.

  In FIG. 8, 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 D121 will be described. The image D121 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 D121 is expressed as shown in FIG.

  Next, the frequency response of the horizontal low frequency component passing means 122 will be described. Since the horizontal low frequency component passing means is realized by a low-pass filter, its frequency response becomes lower as the frequency becomes higher as shown in FIG.

  Finally, the frequency spectrum of the image D122 will be described. An image D122 is obtained by performing low-pass filter processing having the frequency response shown in FIG. 8C on the image D121 having the frequency spectrum shown in FIG. 8B. Therefore, as shown in the image D122, the frequency spectrum of the image D122 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. Accordingly, 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 122.

  Of the processing performed by the image enlarging means 12b, the processing by the vertical zero insertion means 123 and the vertical low frequency component passing means 124 will not be described in terms of the operation on the frequency space. It can be easily understood that there is an action similar to that described with reference to FIG. 8 with respect to the axial direction representing the spatial frequency in the vertical direction. That is, the frequency spectrum of the image D124 is obtained by spreading the frequency spectrum shown in FIG. 8D two-dimensionally.

  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.

  FIGS. 9A to 9E schematically illustrate actions and effects when the intermediate image D111 is generated from the input image DIN when the image D124 obtained by enlarging the original image DORG is input as the input image DIN. 9A is a frequency spectrum of the input image DIN, FIG. 9B is a frequency response of the high-frequency component image generation means 1, and FIG. 9C is a low-frequency component image generation. FIG. 9D shows the frequency response of the means 2, FIG. 9D shows the frequency response of the first intermediate image generation means 111, and FIG. 9E shows the frequency spectrum of the intermediate image D111. In FIG. 9, only one frequency axis is used for the same reason as in FIG.

  Further, FIG. 9 shows the intensity of the frequency spectrum or frequency response 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 DIN will be described. As shown in FIG. 9A, the frequency spectrum of the input image DIN has the same shape as that described in FIG. 8D, and the spectrum SP1 and the aliasing component in which the intensity of the spectrum SPO of the original picture DORG has dropped to some extent. It consists of the spectrum SP2.

  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. 9B.

  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. 9C.

  Next, the frequency response of the intermediate image generating unit 1 will be described. Among the frequency components of the input image DIN, the frequency components in the region RL1 on the low frequency component side shown in FIG. 9D are processed by the high frequency component image generation unit 111A in the first intermediate image generation unit 111. Weakened. On the other hand, the frequency components in the region RH1 on the high frequency component side shown in FIG. 9D are weakened by the low frequency component image generating unit 111B in the first intermediate image generating unit 111. Accordingly, as shown in FIG. 9D, the frequency response of the first intermediate image generation unit 111 is an intermediate region RM1 whose band is limited by the low frequency component side region RL1 and the high frequency component side region RH1. With a peak.

  Next, the frequency spectrum of the intermediate image D111 will be described. The input image DIN having the frequency spectrum shown in FIG. 9A passes through the first intermediate image generating unit 111 having the frequency response shown in FIG. 9D, whereby the intermediate image D111 is obtained. The frequency response of the first intermediate image generation unit 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. In the frequency spectrum, the intensity of the portion included in the low frequency component side region RL1 and the high frequency component side region RH1 in the frequency spectrum of the input image DIN 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 DIN. That is, the first intermediate image generation 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 DIN.

  FIGS. 10A to 10C are views showing the operation and effect of the second intermediate image generation unit 112. FIG. 10A shows the frequency spectrum of the nonlinear processed image D112A, and FIG. FIG. 10C shows the frequency response of the high-frequency component image 112B, and FIG. 10C shows the frequency spectrum of the image D112B. In FIG. 10, for the same reason as in FIG. 9, the intensity of the frequency spectrum or 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. 10A 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.

  11 and 12 are diagrams showing signals obtained when sampling step edges. 11A shows the step edge and the sampling interval S1, FIG. 11B shows a signal obtained when the step edge is sampled at the sampling interval S1, and FIG. 11C shows FIG. It represents the high frequency component of the signal represented in (B). On the other hand, FIG. 12A shows a sampling interval S2 wider than the step edge and the sampling interval S1, and FIG. 12B shows a signal obtained when the step edge is sampled at the sampling interval S2. 12 (C) represents a high frequency component of the signal shown in FIG. 12 (B). 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. 11C and 12C, 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. 13 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. In particular, the first intermediate image generation is performed. The actions and effects of the means 111 and the second intermediate image generating means 112 are shown. As described above, the processing in the first intermediate image generation unit 111 and the second intermediate image generation unit 112 is performed in each of the horizontal direction and the vertical direction, so that the processing is performed one-dimensionally. Therefore, in FIG. 13, the contents of processing are expressed using a one-dimensional signal.

  FIG. 13A shows a signal obtained by sampling the step edge at the sampling interval S2 as in FIG. FIG. 13B is a signal obtained by enlarging the signal shown in FIG. 13A twice. That is, when the original image DORG includes an edge as shown in FIG. 13A, a signal as shown in FIG. 13B is input as the input image DIN. Note that when the signal is doubled, the sampling interval is half that before the expansion, so the sampling interval of the signal shown in FIG. 13B is the same as the sampling interval S1 in FIG. In FIG. 13A, 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. 13C shows a signal representing the high frequency component of the signal shown in FIG. 13B, 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 the high-frequency component of the input image DIN, and therefore includes an aliasing component.

  FIG. 13D shows a signal representing the low frequency component of the signal shown in FIG. 13C, that is, a signal corresponding to the image D111B output from the low frequency component image generating means 111B. Since the image D111B is output as the intermediate image D111 as described above, FIG. 13D corresponds to the intermediate image D111. As shown in FIG. 13D, 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. 13E shows an output signal when the signal shown in FIG. 13D 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. Accordingly, as shown in FIG. 13E, 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. is there.

  FIG. 13F shows a signal representing the high frequency component of the signal shown in FIG. 13E, that is, a signal corresponding to the image D112B output from the high frequency component image generating means 112B. As shown in FIG. 13 (F), the local minimum value near the zero cross point Z in the image D112B appears at the coordinate P1, and the maximum value appears at the coordinate P2, which is the state of the step edge shown in FIG. 11 (C). 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 DIN, and corresponds to the high frequency component near the Nyquist frequency of the original image DORG as shown in FIG. Yes. As described with reference to FIG. 8D, since the spectral intensity near the Nyquist frequency of the original picture DORG is weakened by the enlargement processing means 12b, 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 DIN, it is possible to add a high-frequency component without enhancing the aliasing component, and the resolution of the image can be enhanced. It becomes.

  In the adding means 113, the image D112C is added to the input image DIN as the intermediate image D112. 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 first intermediate image generation unit 111 and the second intermediate image generation unit 112 perform the processing relating to the horizontal direction of the image and the processing relating to the vertical direction in parallel. The above-described effects can be obtained not only in the horizontal direction or in the vertical direction but also in any direction.

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

  Next, the enlargement ratio in the enlargement processing unit 12b 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 the enlargement ratio of the input image DIN is increased, the frequency spectrum is on the low frequency component side as shown by the broken 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 the dotted line portion with respect to the solid line portion in FIG. At this time, the frequency response of the first intermediate image generation unit 111 is the high frequency in the first intermediate image generation unit 111 for the frequency component in the region RL1 on the low frequency component side shown in FIG. Since the frequency component in the region RH1 on the high frequency component side is weakened by the low frequency component image generation unit 111B in the first intermediate image generation unit 111, the frequency component is weakened by the component image generation unit 111A. When the frequency response is as indicated by the dotted line in (C), the frequency response of the first intermediate image generation 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.

  When the image D111 that is an input signal in the second intermediate image generating means 112 is on the low frequency component side as described above, the frequency spectrum of the nonlinear processed image D112A is as shown in FIG. If the frequency response of the high frequency component image generation means 112B is a low frequency component as shown by the dotted line portion with respect to the solid line portion in FIG. 15B, the frequency spectrum of the image D112B is the high frequency in FIG. The component side region RH2 is on the low frequency component side. As a result, when the enlargement ratio is increased, the frequency spectrum of the input image DIN tends to be close to a low frequency component. This can be dealt with by changing the image generating means to extract a low frequency component.

  Therefore, the high frequency component image generating unit 111A receives the control signal CTL corresponding to the enlargement ratio, for example, the frequency component extracted by each of the image generation means can be changed to a low frequency when the enlargement ratio is increased. 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 enlargement ratio.

  In the above description, the video enhancement process is performed on the signal input to the access unit, the signal is recorded, and the video enhancement process is performed on the output signal from the access unit as a reproduction signal. As described above, the video input processing may be performed on the signal input to the access means, and the enhancement processing level may be changed depending on the enlargement ratio in the configuration in which the recording signal is enhanced.

  In the above description, in order to change the degree of enhancement processing according to the enlargement ratio, 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 CTL from the enlargement processing unit 12b. However, instead of the adding means 112C in the signal processing means 11b, a weighted adding means 112D as shown in FIG. 16 is provided, and according to the value of the control signal CTL from the enlargement processing means 12b, 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. 17 is a diagram showing a flow of a video recording / reproducing method according to the second embodiment of the present invention. The image processing method according to the second embodiment of the present invention is performed by a compression processing step ST1, a media access step ST2, and an expansion processing step ST3. , An enlargement processing step ST4 and a signal processing step ST5.

  As shown in FIG. 18, the signal processing step ST5 includes an intermediate image generation step ST5A, an intermediate image generation step ST5B, and an addition step ST5C. The intermediate image generation step ST5A is a high frequency component image generation step ST5A1, a low frequency component image generation step. From ST5A2, the intermediate image generation step ST5B is realized by a non-linear processing step ST5B1, a high frequency component image generation step ST5B2, and an addition step ST5B3.

  As shown in FIG. 19, the high frequency component image generation step ST5A1 includes a horizontal high frequency component passing step ST5A1h and a vertical high frequency component passing step ST5A1v.

  As shown in FIG. 20, the low frequency component image generation step ST5A2 includes a horizontal direction low frequency component passing step ST5A2h and a vertical direction low frequency component passing step ST5A2v.

  As shown in FIG. 21, the nonlinear processing step ST5B1 includes a horizontal nonlinear processing step ST5B1h and a vertical nonlinear processing step ST5B1v.

  As shown in FIG. 22, the high frequency component image generation step ST5B2 includes a horizontal high frequency component passing step ST5B2h and a vertical high frequency component passing step ST5B2v.

  As shown in FIG. 23, the horizontal nonlinear processing step ST5B1h includes a zero-cross determination step ST5B11h and a signal amplification step ST5B12h. The vertical nonlinear processing step ST5B1v includes a zero-cross determination step ST5B11v and a signal amplification step ST5B12v as shown in FIG. Including.

  First, the operation of the intermediate image generation step ST5A will be described according to the flow of FIGS.

  In the high frequency component image generation step ST5A1, the following processing is performed on the input image DIN input in an image input step (not shown). First, in the horizontal high-frequency component image generation step ST5A1h, an image D111Ah obtained by extracting the high-frequency component in the horizontal direction from the input image DIN is generated by the high-pass filter processing in the horizontal direction. In the vertical high-frequency component image step ST5A1v, an image D111Av obtained by extracting the high-frequency component in the vertical direction from the input image DIN is generated by the high-pass filter processing in the vertical direction. That is, the high frequency component image generation step ST5A1 performs the same process 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 DIN. This operation is equivalent to the high frequency component image generation unit 111A.

  In the low frequency component image generation step ST5A2, the following processing is performed on the image D111A. First, in the horizontal low-frequency component image generation step ST5A2h, 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 ST5A2v, 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 ST5A2 performs the same process 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 ST5A. In the intermediate image generation step ST5A, the image D111Bh is the image D111h, the image D111Bv is 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 first intermediate image generating unit 111.

  Next, the operation of the intermediate image processing step ST5B will be described according to the flow of FIGS.

  First, in the nonlinear processing step ST5B2, the following processing is performed on the intermediate image D111.

  First, in the horizontal non-linear processing step ST5B1h, 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. 23 is as follows. First, in the zero cross determination step ST5B11h, 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 ST5B12h. In the signal amplification step ST5B12h, 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 ST5B1h 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 ST5B1v, 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. 24 is as follows. First, in the zero cross determination step ST5B11v, a change in pixel value in the image D111v is confirmed along the vertical direction. 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 positioned above and below the zero cross point are notified to the signal amplification step ST5B12v. In the signal amplification step ST5B12v, 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 ST5B1v performs the same processing as the vertical nonlinear processing means 112Av on the image D111v to generate the image D112Av.

  The above is the operation of the nonlinear processing step ST5B1, and the nonlinear processing step ST5B1 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 ST5B2, the following processing is performed on the image D112A.

  First, in the horizontal high-frequency component image generation step ST5B2h, an image D112Bh obtained by performing a horizontal high-pass filter process on the image D112Ah is generated. That is, the horizontal direction high frequency component image generation step ST5B2h performs the same processing as the horizontal direction high frequency component image generation means 112Bh.

  Next, in the vertical direction high frequency component image generation step ST5B2v, 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 ST5B2v 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 ST5B2, and the high frequency component image generation step ST5B2 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 ST5B3, the image D112B and the intermediate image D111 are added to generate an image D112C. At this time, the addition of the images D112B and D111 may be weighted addition. This operation is equivalent to the adding means 112C.

  The above is the operation of the intermediate image processing step ST5B. The intermediate image processing step ST5B outputs the image D112C as the intermediate image D112. This operation is equivalent to the second intermediate image generating unit 112.

  In the addition step ST5C, the input image 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 of the image processing method in the present invention. That is, the operation of the adding step ST5C 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.

  In the above description, the video recording / reproducing apparatus has been described. However, the same enhancement processing may be performed in a video reproducing apparatus that does not record video with the same configuration.

  In the text, what is processed as a single picture is an image, and what flows in time series is a video or video signal.

1 video recording and playback device, 2 recording media, 3a input terminal, 3b output terminal,
11a, 11b Signal processing means, 12a, 12b Enlargement processing means, 13 Compression processing means, 14 Access means, 15 Decompression processing means.

Claims (13)

Access means for reproducing the image data recorded on the recording medium and outputting the reproduced image data;
Decompression processing means for decompressing the reproduced image data and outputting a reproduced video signal;
An enlargement processing means for performing an image enlargement process on the reproduced video signal and outputting an image enlargement video signal and an enlargement rate signal indicating an image enlargement rate;
Signal processing means for generating a video output signal to which a high-frequency component generated by performing nonlinear processing on the image enlarged video signal is added,
The signal processing means includes
First intermediate image generation means for generating a first intermediate image by extracting a signal in a frequency band set based on the enlargement ratio signal from the image enlargement signal;
A signal in a frequency band set based on the magnification signal is extracted from a high-frequency component generated by performing non-linear processing on the first intermediate image, and is added to the first intermediate image to add a second Second intermediate image generation means for generating an intermediate image;
An image reproducing apparatus comprising: an adding means for adding the image input image and the second intermediate image to generate the image output signal. The first intermediate image generating means includes
First high-frequency component image generation that generates a first high-frequency component image obtained by extracting only the high-frequency component of the input image and changes a frequency component of a signal to be extracted according to a control signal from the enlargement processing unit And low frequency component image generation means for taking out only 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 enlargement processing means. The video reproducing apparatus according to claim 1. The second intermediate image generating means includes
Nonlinear processing means for performing nonlinear processing on the first intermediate image to generate a first high-frequency component image;
Second high-frequency component image generation means for generating a second high-frequency component image by extracting a signal in a frequency band set based on the magnification signal from the first high-frequency component image;
2. The video reproduction apparatus according to claim 1, further comprising adding means for adding the first intermediate image and the second high-frequency component image to generate the second intermediate image. 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;
3. The video according to claim 2, further comprising: a vertical low-frequency component image generation unit configured to generate a first vertical intermediate image obtained by extracting only a low-frequency component of the first vertical high-frequency component image. 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 processed image obtained by amplifying each pixel value adjacent to a 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;
4. A second vertical high-frequency component image generation unit that generates a second vertical high-frequency component image obtained by extracting only the high-frequency component of the vertical nonlinear processed image. Video playback device. The horizontal non-linear processing means includes:
According to the determination result of the horizontal zero-cross point determining means for determining a zero-cross point as a zero-cross point where the pixel value of the first horizontal intermediate image changes from positive to negative or from negative to positive. Horizontal signal amplifying means for determining an amplification factor for each pixel of the first horizontal intermediate image;
The vertical nonlinear processing means includes:
Vertical zero-cross point determination means for determining a point where the pixel value of the first vertical intermediate image changes from positive to negative or from negative to positive as a zero-cross point;
6. The video reproduction according to claim 5, 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. apparatus. An enlargement processing means for performing an image enlargement process on the video input signal and outputting an image enlargement video signal and an enlargement rate signal indicating an image enlargement rate;
A signal processing means for generating a recording video signal to which a high-frequency component is generated by performing non-linear processing on the image enlargement video signal;
Compression means for compressing the recorded video signal and generating recorded image data;
Access means for recording the recorded image data on a recording medium,
The signal processing means includes
First intermediate image generation means for generating a first intermediate image by extracting a signal in a frequency band set based on the enlargement ratio signal from the image enlargement video signal;
A signal in a frequency band set based on the magnification signal is extracted from a high-frequency component generated by performing non-linear processing on the first intermediate image, and is added to the first intermediate image to add a second Second intermediate image generation means for generating an intermediate image;
A video recording / reproducing apparatus comprising: an adding means for adding the image input image and the second intermediate image to generate the recorded video signal. The first intermediate image generating means includes
First high-frequency component image generation that generates a first high-frequency component image obtained by extracting only the high-frequency component of the input image and changes a frequency component of a signal to be extracted according to a control signal from the enlargement processing unit And low frequency component image generation means for taking out only 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 enlargement processing means. The video recording / reproducing apparatus according to claim 7. The second intermediate image generating means includes
Nonlinear processing means for performing nonlinear processing on the first intermediate image to generate a first high-frequency component image;
Second high-frequency component image generation means for generating a second high-frequency component image by extracting a signal in a frequency band set based on the magnification signal from the first high-frequency component image;
8. The video recording / reproducing apparatus according to claim 7, further comprising adding means for adding the first intermediate image and the second high-frequency component image to generate the second intermediate image. 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 generation 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;
9. The video according to claim 8, further comprising vertical low frequency component image generation 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 processed image obtained by amplifying each pixel value adjacent to a 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;
The second vertical high-frequency component image generation means for generating a second vertical high-frequency component image obtained by extracting only the high-frequency component of the vertical non-linear processing image. Video recording / playback device. The horizontal non-linear processing means includes:
According to the determination result of the horizontal direction zero cross point determination unit that determines 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, and the determination result of the horizontal direction zero cross point determination unit Horizontal signal amplification means for determining an amplification factor for each pixel of the first horizontal intermediate image,
The vertical nonlinear processing means includes:
Vertical zero-cross point determination means for determining a point where the pixel value of the first vertical intermediate image changes from positive to negative or from negative to positive as a zero-cross point;
12. The video recording according to claim 11, further comprising a vertical signal amplifying unit that determines an amplification factor for each pixel of the first vertical intermediate image in accordance with a determination result of the vertical zero-cross point determining unit. Playback device. An enlargement processing step of performing image enlargement processing on the video signal and outputting an image enlargement video signal and an enlargement rate signal indicating an image enlargement rate;
In a video recording / reproducing method comprising: a signal processing step of generating a video output signal to which a high-frequency component generated by performing nonlinear processing on the image enlarged video signal is added;
The signal processing step comprises:
A first intermediate image generation step of generating a first intermediate image by extracting a signal in a frequency band set based on the magnification ratio signal from the image magnification signal;
A signal in a frequency band set based on the magnification signal is extracted from a high-frequency component generated by performing non-linear processing on the first intermediate image, and is added to the first intermediate image to add a second A second intermediate image generating step for generating an intermediate image;
A video recording / reproducing method comprising: an adding step of generating the video signal by adding the image input image and the second intermediate image.

Images