JP2011035854A - Conversion device and reproduction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce color blurring when a video signal in a first format is converted to a second format. <P>SOLUTION: A conversion device includes an acquisition means of acquiring a video signal in a first format, an extraction means of sequentially extracting a plurality of color signals as one unit in the video signal in the first format, the color signals having the same color difference and being adjacent, a generation means of generating a color signal for interpolation using the plurality of color signals, and an output means of converting the video signal in the first format to the second format based upon the generated color signal for interpolation and outputting the resulting signal. The generation means includes an edge detection means of detecting whether an edge is present between adjacent color signals among the plurality of extracted color signals, a correction means of correcting some of the plurality of color signals based upon the position of the edge, and an interpolation signal generation means of generating the color signal for interpolation using the corrected color signals. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a conversion device that converts a video signal of a first format into a second format having a larger amount of information than the first format. More specifically, the present invention relates to a conversion device that generates an interpolation color signal based on a first format color signal and generates a second format using the interpolation color signal.

  Currently, YCbCr signals are used for video signals included in broadcast waves and optical discs (Blu-ray Discs). The video signal uses a format in which the color difference signal of 4: 2: 0 format is reduced, not the 4: 2: 2 format or the 4: 4: 4 format. These are used in consideration of the information amount of the video signal.

  Here, in a reproducing apparatus that reproduces a video signal such as the 4: 2: 0 format, it is necessary to interpolate the reduced color difference signal in order to reproduce the video signal. Therefore, in the playback device, when a 4: 2: 0 format video signal is played back in the 4: 4: 4 format, the 4: 2: 0 format is first changed to the 4: 2: 2 format, and then the 4: 2 format is used. : Converts from 2 to 4: 4: 4 format. At the time of the conversion, an interpolation processing method is determined using the property that there is a correlation between luminance information and color difference information, and the color difference information is interpolated by the determined interpolation method (Patent Document 1).

JP-A-4-358490

  By the way, in the playback apparatus, as described above, when the video signal of the first format such as 4: 2: 2 format is converted to the second format such as 4: 4: 4 format, as shown in FIG. Problems arise. This will be specifically described.

  FIG. 10 illustrates the 8 tap interpolation process at the pixel position Cb [n] with Cb of the color difference information as an example. In FIG. 10, the horizontal axis indicates the pixel position, and the vertical axis indicates the color signal level. In FIG. 10, the color signal levels of Cb [n-7] to Cb [n + 1] are low, and the color signal levels of Cb [n + 3] to Cb [n + 7] are high.

  Here, the reproducing apparatus calculates the average value of the color signal levels using the color signal levels of the color difference signals of the above 8 taps (Cb [n-7] to Cb [n + 7]), and uses the calculated color signal level. It is assumed that the color difference signal for interpolation (Cb [n]) is used. In this case, the color signal level of the interpolation color difference signal (Cb [n]) is influenced by Cb [n + 3] to Cb [n + 7]. That is, the generated interpolating color difference signal (Cb [n]) causes color blur between Cb [n−1] and Cb [n + 1].

  Note that a rapid change in the color signal level between Cb [n + 1] and Cb [n + 3] as shown in FIG. 10 is caused by the OSD (on-screen display) in the original image data (4: 2: 2 format). This is likely to occur when other images such as (display) (4: 2: 2 format) are overlaid.

  SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a conversion device that can reduce the occurrence of color blur when converting a video signal of a first format to a second format.

  The conversion device of the present invention converts a video signal in the first format into a second format having a larger amount of information than the first format. The conversion apparatus sequentially extracts a plurality of color signals that have the same color difference and are adjacent to each other in the acquisition unit that acquires the video signal of the first format and the video signal of the first format as one unit. Extraction means, generation means for generating an interpolation color signal using the plurality of extracted color signals, and the acquired first format based on the interpolation color signal generated by the generation means Output means for converting and outputting the video signal to a second format. The generating unit is configured to detect, in the plurality of extracted color signals, an edge detecting unit that detects whether an edge exists between adjacent color signals, and the plurality of color signals based on the detected edge positions. Correction means for correcting a part of the color signals, and interpolation signal generation means for generating the interpolation color signal using the corrected color signal.

  In this way, it is possible to detect a portion where an edge exists between adjacent color signals and correct a part of the color signal in accordance with the edge. Therefore, it is possible to generate a color signal for interpolation without using color difference information that causes color blurring.

  According to the present invention, it is possible to reduce the occurrence of color blur when converting a video signal of the first format to the second format.

Configuration diagram of player according to the present embodiment Functional block diagram of an HDMI LSI according to the present embodiment Functional block diagram in the conversion block for HDMI transmission according to the present embodiment The figure for demonstrating the input signal and output signal in the conversion block for HDMI transmission which concerns on this Embodiment The flowchart which shows the operation example of the interpolation process which concerns on this Embodiment The figure for demonstrating 2TAP processing which concerns on this Embodiment The figure for demonstrating the 1st 8TAP process which concerns on this Embodiment. The figure for demonstrating the 2nd 8TAP process which concerns on this Embodiment. The figure for demonstrating the 3rd 8TAP process which concerns on this Embodiment. Illustration for explaining the problem

(Embodiment 1)
The player 100 according to the present embodiment will be described <1. Overview of the present embodiment>
The player 100 acquires a 4: 2: 0 format video signal from the optical disk placed on the drive device 110. The player 100 converts the received 4: 2: 0 format video signal into the 4: 2: 2 format or 4: 4: 4 format and outputs the converted signal to the TV 200.

  The player 100 performs the following interpolation processing when converting a 4: 2: 2 format video signal into a 4: 4: 4 format. First, the player 100 acquires a plurality (eight) of color difference signals having the same color difference and adjacent to each other from the 4: 2: 2 format video signal. That is, the player 100 acquires eight color difference signals adjacent in Cb or Cr from the video signal in the 4: 2: 2 format. Then, the player 100 detects whether or not there is an edge (a portion where the color level difference is equal to or greater than the threshold) between adjacent color difference signals among the eight color difference signals. When the player 100 determines that an edge exists, the player 100 corrects some of the eight color difference signals based on the position of the edge. Then, the player 100 generates an interpolation color difference signal by using the eight color difference signals including the corrected color difference signal. The player 100 repeats such processing for the entire video signal in the 4: 2: 2 format.

  In this way, it is possible to detect a portion where an edge exists between adjacent color difference signals and correct a part of the color difference signal in accordance with the edge. Therefore, it is possible to generate a color difference signal for interpolation without using color difference information that causes color blurring.

<2. Configuration>
<2.1 Description of Overall Configuration and Configuration of Player 100 (FIG. 1)>
FIG. 1 is an illustration of the overall configuration. Each configuration will be described below.

  The player 100 reads video and audio signals from the optical disc inserted in the drive device 110. Then, the player 100 outputs the read video and audio signals to the TV 200 via the HDMI terminal 140. The TV 200 displays the video and audio signals input from the player 100 as a display screen and outputs them as audio.

  The player 100 includes a drive device 110, an LSI 120, an HDMI LSI 130, and an HDMI terminal 140. This will be specifically described below.

  The drive device 110 reads a signal from the optical disk and outputs a signal to the LSI 120. As the optical disc, a BD (Blu-ray Disc), a DVD (Digital Versatile Disc), or the like can be considered. In this embodiment, it is assumed that a signal obtained by multiplexing a video signal (video signal), an audio signal (audio signal), and a data signal is stored on the optical disc. In addition, it is assumed that the video signal and the audio signal are compression-coded. It is assumed that the video signal is in 4: 2: 0 format (YCbCr format).

  When receiving a signal from the drive device 110, the LSI 120 performs a decoding process, converts the signal into a 4: 2: 2 format, and outputs the signal to the HDMI LSI 130. Specifically, the LSI 120 separates the multiplexed signal into a video signal, an audio signal, and a data signal. Then, the LSI 120 decodes each of the separated video signal and audio signal. Thus, a decoded 4: 2: 0 format video signal is generated. Further, the video signal is converted from the 4: 2: 0 format to the 4: 2: 2 format before being transmitted to the HDMI LSI 130. That is, the LSI 120 converts the decoded 4: 2: 0 format video signal into the 4: 2: 2 format. The LSI 120 outputs a 4: 2: 2 format video signal and audio signal to the HDMI LSI 130. The LSI 120 outputs a data signal to the HDMI LSI 130. The LSI 120 can be realized by a semiconductor chip (LSI).

  Here, the LSI 120 can superimpose an OSD (on-screen display) on the acquired video signal. This process will be briefly described. When the LSI 120 receives an instruction to superimpose an OSD on a video signal by a user operation or the like, the LSI 120 reads OSD information recorded in advance in the LSI 120. Then, the LSI 120 superimposes the read OSD information on the video signal acquired from the drive device 110. Here, the LSI 120 holds OSD information in 4: 4: 4 format. Therefore, the LSI 120 enlarges the OSD information at a ratio of luminance information: color difference information = 2: 1. For example, the LSI 120 enlarges only the luminance information twice. As a result, the LSI 120 obtains OSD information in 4: 2: 2 format. The LSI 120 superimposes this 4: 2: 2 format OSD information on the acquired video signal. In this way, the LSI 120 can superimpose OSD information on the acquired video signal. Note that the LSI 120 can also superimpose the secondary video on the primary video when the video signal is in the BD format.

  The HDMI LSI 130 receives a signal from the LSI 120 and performs signal processing for performing HDMI output. The HDMI LSI 130 then outputs the signal that has undergone signal processing to the HDMI terminal 140. Specifically, the HDMI LSI 130 converts a 4: 2: 2 format video signal into a 4: 4: 4 format (no processing is required when outputting 4: 2: 2 as it is), and converts the converted signal to Output to the HDMI terminal 140. The HDMI LSI 130 can be realized by a semiconductor chip (LSI). Details of the HDMI LSI 130 will be described later.

  The HDMI terminal 140 receives a signal from the HDMI LSI 130 and outputs data to the TV 200. The HDMI terminal 140 enables information exchange with the TV 200. That is, the HDMI terminal 140 is configured to be electrically connectable with the TV 200.

  The power source 150 converts an AC current obtained from a household power source into a DC current, and supplies power to each unit (LSI 120, HDMI LSI 130, etc.) of the player 100.

<2.2 Functional Block Description of HDMI LSI 130 (FIG. 2)>
Next, functional blocks of the HDMI LSI 130 will be described. FIG. 2 is a diagram for explaining functional blocks of the HDMI LSI 130.

  The HDMI LSI 130 has a CUS 131 and an HDMI transmission conversion block 132 as functional blocks. The HDMI LSI 130 receives a video signal (4: 2: 2 format digital video signal), an audio signal (digital audio signal), and a data signal (packet information) from the LSI 120.

  The CUS 131 performs a chroma upsampling process on the 4: 2: 2 format digital video signal input to the HDMI LSI 130 and converts it to a 4: 4: 4 format digital video signal. The CUS 131 outputs a 4: 4: 4 format digital video signal to the HDMI transmission conversion block 132.

  The HDMI transmission conversion block 132 receives the digital video signal from the CUS 131, the digital audio signal input to the HDMI LSI 130, and the packet information input to the HDMI LSI 130, converts them into an HDMI transmission format, and outputs them. In the present embodiment, the HDMI transmission format is a signal obtained by placing audio signal or data signal packet data in a blank period of a video signal and TMDS converting the signal. TMDS conversion is a method used for baseband transmission of video signals, and converts a video signal from 24 bits to 30 bits and serializes it.

<2.3 Functional Block Description of CUS131 (FIG. 3)>
Next, functional blocks of the CUS 131 will be described. FIG. 3 is a diagram for explaining functional blocks of the CUS 131. The CUS 131 includes a delay block (luminance data) 301, a delay block (color difference data) 302, an interpolation data generation unit 303, a parallel conversion unit (original data) 304, a parallel conversion unit (color difference data) 305, and a synthesis unit 306. Have as.

  The CUS 131 receives a 4: 2: 2 format digital video signal. In the present embodiment, a video signal as shown in FIG. 4 is input from the HDMI LSI 130 to the CUS 131. That is, luminance data and color difference data (Cb or Cr) are input to CUS 131 as one unit. The reason why luminance data and color difference data (Cb or Cr) are used as one unit is to reduce the amount of information transmitted.

  As shown in FIG. 4, the CUS 131 receives one unit of input data (luminance data and color difference data (Cb or Cr)) and outputs one unit of output data (luminance data and color difference data (Cb). ), Color difference data (Cr)) is output.

  Hereinafter, processing of each unit of the CUS 131 when input data of one unit is input will be described. For example, it is assumed that Y [n + 8] and Cr [n + 7] are input to the CUS 131 as input data.

  The delay block (luminance data) 301 acquires luminance (Y) data among the input data. The delay block (luminance data) 301 is a delay block that holds the acquired luminance signal. That is, the delay block (luminance data) 301 holds the inputted luminance data until an instruction to read the luminance data is issued.

  For example, the delay block (luminance data) 301 includes Y [n−1], Y [n], Y [n + 1], Y [n + 2], Y [n + 3], Y [n + 4], Y [ Assume that information such as n + 5], Y [n + 6], and Y [n + 7] is held. In this case, when the delay block (luminance data) 301 acquires new luminance data Y [n + 8], it holds Y [n + 8].

  The delay block (color difference data) 302 acquires color difference (Cb or Cr) data among the input data. The delay block (color difference data) 302 is a delay block that holds the acquired color signal. That is, the delay block (color difference data) 302 holds the input color difference data until an instruction to read the color difference data is issued. In this embodiment, 16 color difference data are held in the delay block (color difference data) 302. When the delay block (color difference data) 302 acquires new color difference data, the delay block (color difference data) 302 outputs the previously acquired color difference data to the parallel conversion unit (original data) 304.

  For example, the delay block (color difference data) 302 includes Cr [n-9], Cb [n-7], Cr [n-7], Cb [n-5], Cr [n-5] as color difference data. , Cb [n-3], Cr [n-3], Cb [n-1], Cr [n-1], Cb [n + 1], Cr [n + 1], Cb [n + 3], Cr [n + 3], Cb Assume that information such as [n + 5], Cr [n + 5], and Cb [n + 7] is held. In this case, when the delay block (color difference data) 302 acquires new color difference data Cr [n + 7], the delay block (color difference data) 302 discards Cr [n-9] and holds Cr [n + 7]. The delay block (color difference data) 302 reads Cr [n−1] and outputs it to the parallel conversion unit (original data) 304.

  The interpolation data generation unit 303 alternately generates Cb and Cr interpolation color difference data based on the color difference data held in the delay block (color difference data) 302. The interpolation data generation unit 303 first acquires Cb or Cr color difference data from the color difference data held in the delay block (color difference data) 302.

  In this case, the interpolation data generation unit 303 acquires eight color difference data related to Cb. The data acquired in this way is adjacent information with the same color difference. The interpolation data generation unit 303 uses this information to generate interpolation color difference data. In this example, the interpolation data generation unit 303 includes Cb [n-7], Cb [n-5], Cb [n-3], Cb [n−1], Cb [n + 1], Cb [n + 3], Based on the information of Cb [n + 5] and Cb [n + 7], the color difference data for interpolation of Cb [n] is generated. The interpolation data generation unit 303 inputs the generated interpolation color difference data to the parallel conversion unit (color difference data) 305. Note that the color difference data for interpolation is <3. This will be described in detail in the section “Interpolation processing>.

  When the generation of the Cb [n] is completed, the interpolation data generation unit 303 acquires eight color difference data related to Cr as the next input data is input. The interpolation data generation unit 303 generates Cr interpolation color difference data based on the acquired color difference data. In this way, the interpolation data generation unit 303 generates interpolation color difference data from the sequentially extracted color difference data. The interpolation data generation unit 303 inputs the generated interpolation color difference data to the parallel conversion unit (color difference data) 305.

  The parallel conversion unit (original data) 304 outputs the input color difference data (Cb) and color difference data (Cr) in one unit. Here, Cb and Cr are alternately input to the parallel conversion unit (original data) 304. Accordingly, when the parallel conversion unit (original data) 304 acquires Cb color difference data, the parallel conversion unit (original data) 304 holds the Cb color difference data. On the other hand, when acquiring the Cr color difference data, the parallel conversion unit (original data) 304 outputs the retained Cb color difference data and the acquired Cr color difference data together. For example, it is assumed that Cr [n−1] is input to the parallel conversion unit (original data) 304. In this case, the parallel conversion unit (original data) 304 should hold Cb [n−1] input immediately before.

  Therefore, the parallel conversion unit (original data) 304 combines Cb [n−1] and Cr [n−1] and outputs the combined result to the combining unit 306. In short, the parallel conversion unit (original data) 304 outputs the sequentially acquired Cb and Cr color difference data to the synthesis unit 306 every 2 m clock.

  The parallel conversion unit (color difference data) 305 outputs the input interpolation color difference data (Cb) and the interpolation color difference data (Cr) in one unit. Here, Cb and Cr are alternately input to the parallel conversion unit (color difference data) 305.

  Therefore, the parallel conversion unit (color difference data) 305 holds the Cb interpolation color difference data when the Cb interpolation color difference data is acquired. On the other hand, when the parallel conversion unit (color difference data) 305 acquires Cr color difference data for interpolation, the parallel conversion unit (color difference data) 305 outputs the stored Cb interpolation color difference data and the acquired Cr color difference data for interpolation together. For example, when the parallel conversion unit (color difference data) 305 acquires Cb [n], it holds Cb [n]. In short, the parallel conversion unit (color difference data) 305 outputs the Cb and Cr interpolation color difference data sequentially acquired to the synthesis unit 306 every 2m + 1 clock.

  The combining unit 306 outputs the luminance data acquired from the delay block (luminance data) 301 and the color difference data input from the parallel conversion unit (original data) 304 or the parallel conversion unit (color difference data) 305 and outputs To do. For example, when Cb [n−1] and Cr [n−1] are acquired, the synthesis unit 306 acquires Y [n−1] from the delay block (luminance data) 301 and outputs it.

  In this way, the CUS 131 can convert a 4: 2: 2 format video signal into a 4: 4: 4 format.

<2.4 Explanation of Input Data and Output Data of CUS131>
The input data and output data in the CUS 131 described above will be described. FIG. 4 is a diagram illustrating the relationship between input data and output data. Note that the input data and the output data have an internal processing delay of the CUS 131, so the timing of t does not coincide with the timing of s. That is, t indicates the input timing of the input data, and s only indicates the output timing of the output data. Cb1 and Cr1 are data corresponding to the position of Y1, and Cb3 and Cr3 are data corresponding to the position of Y3.

  CUS131 receives Y1 and Cb1 at the timing t. The CUS 131 receives Y2 and Cr1 at the next timing t + 1. In this way, input data is sequentially input.

  On the other hand, CUS131 outputs Y1, Cb1, and Cr1 at the timing of s. The CUS 131 outputs Y2, Cb2, and Cr2 at the next s + 1 timing. Cb2 and Cr2 are interpolated data. In this way, output data is sequentially output.

  In short, Cb1, Cr1, Cb3, and Cr3 are input original data, and Cb2, Cr2, Cb4, and Cr4 are interpolation data by chroma upsampling processing.

<3. Explanation of interpolation processing (FIG. 5)>
The interpolation processing of the present embodiment will be described with an example of the operation of the interpolation data generation unit 303. FIG. 5 is a flowchart for explaining the operation of the interpolation processing of the interpolation data generation unit 303.

First, the interpolation data generation unit 303 acquires eight Cb or Cr color difference data from the delay block (color difference data) 302 (S1).
The interpolation data generation unit 303 will be described by taking as an example a case where eight pieces of color difference data relating to Cb have been acquired as described in the above embodiment. Therefore, the interpolation data generation unit 303 performs Cb [n-7], Cb [n-5], Cb [n-3], Cb [n−1], Cb [n + 1], Cb [n + 3], Cb [n + 5. ], Cb [n + 7] color difference data is acquired. The interpolation data generation unit 303 generates Cb [n] color difference data for interpolation based on this data.

  Next, the interpolation data generation unit 303 detects a difference between adjacent color difference data (S2). For example, the interpolation data generation unit 303 detects a difference in color level between Cb [n-7] and Cb [n-5]. Similarly, the interpolation data generation unit 303 detects the difference in color level between Cb [n-5] and Cb [n-3]. In this way, the interpolation data generation unit 303 detects a difference between adjacent color difference data. In the present embodiment, the difference value is rounded to an absolute value. In other words, it rounds off after the decimal point.

  Next, the interpolation data generation unit 303 refers to the detected difference and determines whether or not the condition 1 or the condition 2 is satisfied (S3).

  [Condition 1] At the position where the color difference data for interpolation is inserted, the difference value between the adjacent color difference data is equal to or less than the first threshold value, and the color level of any one of the adjacent color difference data is “0” (black). It is.

  [Condition 2] At the position where the color difference data for interpolation is inserted, the difference value between adjacent color difference data is equal to or less than the first threshold value, and between the color difference data one distance away from the position where the color difference data for interpolation is inserted. The difference value is less than or equal to the first threshold value.

  Here, “0” is used as the first threshold value of the above condition 1 and condition 2. That is, in the present embodiment, when the color signal levels of adjacent color difference data match, a part of the above condition is satisfied. Further, in the present embodiment, between the color difference data one distance away from the position where the interpolation color difference data is inserted, Cb [n-3], Cb [n-1] (d [2]), and Cb [n + 1] and Cb [n + 3] (d [4]) are shown.

  In short, in step S3, it is determined whether or not the difference between the color difference data near the position where the interpolation color difference data is inserted is small. That is, the interpolation data generation unit 303 detects a flat part.

  For example, in the case of A in FIG. 6, the difference value between Cb [n−1] and Cb [n + 1] (d [3]) is “0”, and the color signal level is “0”. Therefore, the above condition 1 is satisfied, and the process proceeds to step S4. In the case of B in FIG. 6, the difference value between Cb [n−1] and Cb [n + 1] (d [3]) is “0”, and Cb [n + 1] and Cb [n + 3] (d [4] ) Is “0”. Therefore, the above condition 2 is satisfied, and the process proceeds to step S4.

  If the condition is satisfied in step S3, the interpolation data generation unit 303 proceeds to 2TAP processing (S4). The 2TAP process will be described. In the 2TAP processing, the color difference data for interpolation is generated based only on the adjacent color difference data. For example, as illustrated in FIG. 6, the interpolation data generation unit 303 calculates Cb [n] based on the color signal level of Cb [n−1] and the color signal level of Cb [n + 1]. Specifically, the interpolation data generation unit 303 calculates two average values of Cb [n−1] and Cb [n + 1] to obtain the color signal level of Cb [n].

  On the other hand, when step S3 is not satisfied, the interpolation data generation unit 303 determines whether an edge exists at a position one distance away from the position where the interpolation color difference data is inserted (S5). In the interpolation data generation unit 303, first, Cb [n-3] and Cb [n-1] (d [2]), which are positions one away from the position where the interpolation color difference data is inserted, correspond to edges. It is determined whether or not to do so. Then, the interpolation data generation unit 303 determines whether or not Cb [n + 1] and Cb [n + 3] (d [4]), which are one position away from the position where the interpolation color difference data is inserted, correspond to edges. Determine. That is, in the above example, Cb [n-3] and Cb [n-1], and Cb [n + 1] and Cb [n + 3] are separated from the position where the interpolation color difference data is inserted. It is shown that. A specific operation will be described below. The following explanation is an operation example when it is determined whether or not Cb [n + 1] and Cb [n + 3] (d [4]) correspond to edges.

  [Operation of S5-1] First, the interpolation data generation unit 303 sets the second threshold value based on the difference value at a position (for example, d [4]) one position away from the position where the color difference data for interpolation is inserted. calculate. The interpolation data generation unit 303 calculates the second threshold value by dividing the difference value of d [4] by a predetermined value (for example, 5).

  [Operation of S5-2] Next, the interpolation data generation unit 303 calculates the difference value between the color difference data near the boundary (d [4]) in the two areas divided by the boundary (d [4]). It is determined whether or not it is smaller than two threshold values. Here, in the present embodiment, the color difference data near the boundary includes the space between the color difference data at three positions away from the boundary (an example of a position away from the boundary by a predetermined range). That is, when the boundary is d [4], d [1], d [2], d [3], d [5], and d [6] are between the color difference data near the boundary. Therefore, the interpolation data generation unit 303 determines whether the difference value between d [1], d [2], d [3], d [5], and d [6] is smaller than the second threshold value. . The interpolation data generation unit 303 determines that the boundary is an edge when the difference values between the color difference data near the boundary are all smaller than the second threshold value. On the other hand, when a part of the difference value between the color difference data near the boundary is equal to or larger than the second threshold, the interpolation data generation unit 303 determines that the edge is not an edge.

  [Operation of S5-3] That is, if the interpolation data generation unit 303 determines that an edge exists at a position one distance away from the interpolation position, the process proceeds to step S6. On the other hand, if it is determined that no edge exists at a position one distance away from the interpolation position, the interpolation data generation unit 303 proceeds to step S7.

  If the condition is satisfied in step S5, the interpolation data generation unit 303 proceeds to the first 8TAP process (S6). The first 8TAP process will be described.

  First, the interpolation data generation unit 303 uses the detected edge (for example, Cb [n + 1]) with reference to the position (for example, between Cb [n−1] and Cb [n + 1]) where the color difference data for interpolation is inserted. And Cb [n + 3]) are corrected. Specifically, as illustrated in B of FIG. 7, the interpolation data generation unit 303 uses the position (for example, between Cb [n−1] and Cb [n + 1]) where the color difference data for interpolation is inserted as a reference. Then, the color difference data (for example, Cb [n + 1]) existing near the detected edge (for example, between Cb [n + 1] and Cb [n + 3]) is used for correction. That is, the interpolation data generation unit 303 replaces the color difference data of Cb [n + 3], Cb [n + 5], and Cb [n + 7] with the same color signal level as Cb [n + 1]. In this way, the interpolation data generation unit 303 corrects the color difference data existing at a position farther than the detected edge (for example, between Cb [n + 1] and Cb [n + 3]) (B in FIG. 7). In the present embodiment, the corrected color difference data is Cb [n + 3] ′, Cb [n + 5] ′, and Cb [n + 7] ′.

  Then, the interpolation data generating unit 303 generates interpolation color difference data using the corrected color difference data. For example, the interpolation data generation unit 303 corrects the corrected Cb [n + 3] ′, Cb [n + 5] ′, Cb [n + 7] ′, Cb [n−7], Cb [n−5], and Cb [n−. 3], Cb [n−1], and Cb [n + 1] are used to calculate an average value, and the calculated information is used as the color signal level of Cb [n].

  Returning to the description of FIG. 5, when the step S5 is not satisfied, the interpolation data generation unit 303 determines whether an edge exists at a position two away from the interpolation position (S7). In the interpolation data generation unit 303, first, Cb [n-5] and Cb [n-3] (d [1]), which are two positions away from the position where the interpolation color difference data is inserted, correspond to edges. It is determined whether or not to do so. Then, the interpolation data generation unit 303 determines whether or not Cb [n + 3] and Cb [n + 5] (d [5]), which are two positions away from the position where the interpolation color difference data is inserted, correspond to edges. Determine. That is, in the above example, Cb [n−5] and Cb [n−3] and Cb [n + 3] and Cb [n + 5] are separated from the position where the interpolation color difference data is inserted by two positions. It is shown that. A specific operation will be described below. The following description is an operation example when it is determined whether or not Cb [n + 3] and Cb [n + 5] (d [5]) correspond to edges.

  [Operation of S7-1] First, the interpolation data generation unit 303 sets the second threshold value based on the difference value at a position (for example, d [5]) that is two distances from the position where the color difference data for interpolation is inserted. calculate. The interpolation data generation unit 303 calculates the second threshold value by dividing the difference value of d [5] by a predetermined value (for example, 5).

  [Operation of S7-2] Next, the interpolation data generation unit 303 calculates the difference value between the color difference data near the boundary (d [5]) in the two areas divided by the boundary (d [5]). It is determined whether or not it is smaller than two threshold values. Here, in the present embodiment, the color difference data near the boundary includes the space between the color difference data at three positions away from the boundary. That is, when the boundary is d [5], d [2], d [3], d [4], and d [6] are between the color difference data near the boundary. Therefore, the interpolation data generation unit 303 determines whether the difference value between d [2], d [3], d [4], and d [6] is smaller than the second threshold value. The interpolation data generation unit 303 determines that the boundary is an edge when the difference values between the color difference data near the boundary are all smaller than the second threshold value. On the other hand, when a part of the difference value between the color difference data near the boundary is equal to or larger than the second threshold, the interpolation data generation unit 303 determines that the edge is not an edge.

  [Operation of S7-3] That is, if it is determined that an edge exists at a position two away from the interpolation position, the interpolation data generation unit 303 proceeds to step S8. On the other hand, if it is determined that no edge exists at a position two away from the interpolation position, the interpolation data generation unit 303 proceeds to step S9.

  If the condition is satisfied in step S7, the interpolation data generation unit 303 proceeds to the second 8TAP process (S8). The second 8TAP process will be described.

  First, the interpolation data generation unit 303 detects a detected edge (for example, Cb [n + 3]) with reference to a position (for example, between Cb [n−1] and Cb [n + 1]) at which interpolation color difference data is inserted. And Cb [n + 5]) are corrected. Specifically, as illustrated in B of FIG. 8, the interpolation data generation unit 303 uses the position (for example, between Cb [n−1] and Cb [n + 1]) where the color difference data for interpolation is inserted as a reference. Then, the color difference data (for example, Cb [n + 3]) existing near the detected edge (for example, between Cb [n + 3] and Cb [n + 5]) is used for correction. That is, the interpolation data generation unit 303 replaces the color difference data of Cb [n + 5] and Cb [n + 7] with the same color signal level as Cb [n + 3]. In this manner, the interpolation data generation unit 303 corrects the color difference data existing at a position farther than the detected edge (for example, between Cb [n + 3] and Cb [n + 5]) (B in FIG. 8). In the present embodiment, the corrected color difference data is Cb [n + 5] ′, Cb [n + 7] ′.

  Then, the interpolation data generating unit 303 generates interpolation color difference data using the corrected color difference data. For example, the interpolation data generation unit 303 corrects Cb [n + 5] ′, Cb [n + 7] ′, Cb [n−7], Cb [n−5], Cb [n−3], and Cb [n]. −1], Cb [n + 1], and Cb [n + 3], the average value is calculated, and the calculated information is set as the color signal level of Cb [n].

  Returning to the description of FIG. 5, when the condition is not satisfied in step S7, the process proceeds to the third 8TAP process (S9). The third 8TAP process will be described. The interpolation data generation unit 303 generates interpolation color difference data using the acquired eight color difference data. Specifically, the interpolation data generation unit 303 calculates an average value of the color difference data of the eight color difference data, and sets the calculated average value as the color signal level of Cb [n].

  In this way, the interpolation data generation unit 303 performs the interpolation process. In this example of operation, the Cb interpolation process has been described, but Cr can also be realized by the same method.

<4. Summary>
In the present embodiment, the player 100 converts the video signal in the 4: 2: 0 format into the 4: 2: 2 format. The player 100 is a device that converts a 4: 2: 2 format video signal into a 4: 4: 4 format. The player 100 includes the following control blocks in order to convert a 4: 2: 2 format video signal into a 4: 4: 4 format.

  The player 100 uses a delay block (color difference data) 302 for acquiring a 4: 2: 2 format video signal and eight color differences in the 4: 2: 2 format video signal that have the same color difference and are adjacent to each other. An interpolation data generation unit 303 that sequentially extracts signals as one unit, an interpolation data generation unit 303 that generates interpolation color difference signals using the extracted eight color difference signals, and an interpolation data generation unit 303 A synthesizing unit 306 that converts a 4: 2: 2 format video signal into a 4: 4: 4 format based on the interpolated color difference signal and outputs the converted video signal. Then, the interpolation data generation unit 303 determines whether or not there is an edge between adjacent color difference signals in the extracted eight color difference signals, and based on the detected edge position. A correction unit that corrects a part of the individual color difference signals; and an interpolation signal generation unit that generates an interpolation color difference signal using the corrected color difference signal.

  In this way, it is possible to detect a portion where an edge exists between adjacent color difference signals and correct a part of the color difference signal in accordance with the edge. Therefore, it is possible to generate a color difference signal for interpolation without using color difference information that causes color blurring.

  In addition, the interpolation data generation unit 303 determines whether or not the color level difference between adjacent color difference signals is equal to or less than the first threshold in the extracted eight color difference signals where the correction color difference signal is interpolated. And a signal generation unit that generates an interpolating color difference signal using a part of the extracted eight color difference signals when the determination unit determines that the value is equal to or less than the first threshold value; Have

  In this way, when the difference value between adjacent color difference data is small at the position where the interpolation color difference data is inserted, the color difference data for interpolation is generated using only the color difference data near the insertion position. become able to. Therefore, it is possible to generate a color difference signal for interpolation without using color difference information that causes color blurring.

  In step S3, the interpolation data generation unit 303 determines whether the difference value of the adjacent color difference data is equal to or less than the first threshold at the position where the interpolated color difference data is inserted, and any of the adjacent color difference data One of the color levels is “0” (black). "Is satisfied or not. That is, it is determined whether not only the difference value of the adjacent color difference data is equal to or less than the first threshold value, but also satisfies whether the color level of any one of the color difference data is “0” (black). .

  In this way, if the adjacent color difference data is black at the position where the interpolation color difference data is inserted, the color difference data for interpolation can be generated using a part of the plurality of color difference data. Therefore, the number of color difference data used for generating the color difference data for interpolation can be reduced at a position that is sensitive to a change in color difference level, such as black, that is, at a position where the change in color difference level is likely to appear as a color blur. For this reason, it is possible to reduce the occurrence of color blur in an image due to the influence of color difference data having a color signal level.

  Similarly, in step S3, the interpolation data generation unit 303 determines that the difference value between adjacent color difference data is equal to or less than the first threshold value and the interpolation color difference data is equal to or less than the first threshold value at the position where the color difference data for interpolation is inserted. It is determined whether or not the difference value between the color difference data one distance away from the insertion position is equal to or less than the first threshold value ”. That is, it is determined whether or not the difference value between the adjacent color difference data is not more than the first threshold value, and whether or not the difference value at a position one distance away satisfies the first threshold value or less.

  In this way, it is possible to further reduce the occurrence of color blur at a position where the color signal level is highly likely to be flat.

In the present embodiment, as in steps S5 and S7, it is determined whether or not an edge exists at a position one or two away from the position where the interpolation color difference data is inserted. However, the present invention is not limited to this, and it may be determined whether or not an edge exists at three positions apart.
(Other embodiments)
The first embodiment has been exemplified as the present embodiment. However, the present invention is not limited to this. Therefore, other embodiments of the present invention will be described collectively below. In addition, this invention is not limited to these, It is applicable also to embodiment modified suitably.

  In the first embodiment, the operation when converting the first format into the 4: 2: 2 format and the second format into the 4: 4: 4 format has been described as an example. However, the present invention is not limited to this, and the first format may be 4: 2: 0 format and the second format may be 4: 2: 2 format. In other words, the second format may be anything as long as the second format has more information than the first format.

  In the first embodiment, the interpolation data generation unit 303 extracts eight color difference signals from the delay block (color difference data) 302. Since this is an example, the number of color difference signals to be extracted may be any number as long as it is plural.

  In the first embodiment, the edge is detected by the method of step S5 or S7. However, the present invention is not limited to this, and it may be realized by the following method. The following example is an example of step S5.

  In another embodiment, when step S3 is not satisfied, the interpolation data generation unit 303 determines whether or not the condition 3 and the condition 4 are satisfied (S5).

  [Condition 3] The difference value between the color difference data one distance away from the position where the interpolation color difference data is inserted is greater than or equal to the second threshold value.

  [Condition 4] In the two areas divided by the position where the difference value is equal to or greater than the second threshold value in Condition 3, the difference between the color difference data near the boundary is equal to or less than the third threshold value.

  Here, the second threshold value may be any value as long as it is the same value as the third threshold value or larger than the third threshold value (for example, 4 times). Also, between the color difference data one distance away from the position where the interpolation color difference data is inserted, in this embodiment, Cb [n−3] and Cb [n−1], and Cb [n + 1] and Cb. [N + 3] is shown. Further, the color difference data near the boundary includes the color difference data at a position three away from the boundary. That is, when the boundary is d [4], d [1], d [2], d [3], d [5], and d [6] are between the color difference data near the boundary. On the other hand, when the boundary is d [2], d [0], d [1], d [3], d [4], and d [5] are between the color difference data near the boundary.

  In short, in step S5, it is determined whether or not there is a large difference between the color difference data one distance away from the position where the interpolation color difference data is inserted. That is, the interpolation data generation unit 303 detects a position that can be an edge. In addition, when the difference between the color difference data is large, the interpolation data generation unit 303 determines whether or not the difference between the color difference data near the boundary is small in the two areas divided by the portion where the difference is large. . That is, the interpolation data generation unit 303 detects whether or not the vicinity that can be an edge is flat in the two areas divided at the position that can be the detected edge.

  For example, in the case of A in FIG. 7, the difference between Cb [n + 1] and Cb [n + 3] is d [4] (assumed to be greater than or equal to the second threshold). In the case of A in FIG. 7, the differences in the portions other than the above d [4] are d [1], d [2], d [3], d [5], and d [6] It is assumed that it is below the threshold. Therefore, the above conditions 3 and 4 are satisfied, and the process proceeds to step S6. Here, in A of FIG. 7, it can be determined that the color difference data of Cb [n + 1] and Cb [n + 3] is an edge. This makes it possible to detect an edge.

  In the first embodiment, the color difference signal is taken as an example of the color signal, but is not limited thereto.

  The present invention can be applied to a player, a recorder, a television receiver, or the like having a conversion device that converts a video signal of the first format into the second format.

100 player 110 drive device 120 LSI
130 HDMI LSI
140 HDMI terminal 150 Power supply 200 TV
131 CUS (Chroma Up Sampling)
132 Conversion block for HDMI transmission 301 Delay block (luminance data)
302 Delay block (color difference data)
303 Interpolation data generation unit 304 Parallel conversion unit (original data)
305 Parallel conversion unit (interpolation data)
306 Synthesis unit

Claims (10)

A conversion device for converting a video signal of a first format into a second format having a larger amount of information than the first format,
Obtaining means for obtaining a video signal of the first format;
Extraction means for sequentially extracting a plurality of adjacent color signals having the same color difference in the first format video signal as one unit;
Generating means for generating an interpolating color signal using the extracted plurality of color signals;
Output means for converting the acquired video signal of the first format into a second format based on the interpolation color signal generated by the generating means, and outputting the second format video signal;
With
The generating means includes
Edge detection means for detecting whether or not an edge exists between adjacent color signals in the plurality of extracted color signals;
Correction means for correcting a part of the plurality of color signals based on the position of the detected edge;
Interpolation signal generation means for generating the interpolation color signal using the corrected color signal;
Having
Conversion device. The edge detection means includes
In the extracted plurality of color signals, a difference in color level between adjacent color signals is detected, and whether or not an edge exists between adjacent color signals is detected according to the detected detection result.
The conversion device according to claim 1. When the generating means generates an interpolating color signal that is interpolated between the first color signals,
The detecting means detects whether or not an edge exists between the first color signals and between the second color signals separated by one, or between the third color signals separated by two;
The conversion device according to claim 1. In the case where the generating unit generates an interpolating color signal interpolated between the first color signals, and the detecting unit detects an edge between the fourth color signals,
The correction means includes
Correcting color signals that are further apart than between the fourth color signals with reference to the first color signals;
The conversion device according to claim 1. The correction unit corrects the partial color signal using a color level of a color signal that is not corrected.
The conversion device according to claim 1. The first format is a 4: 2: 2 format, the second format is a 4: 4: 4 format, and the color signal is a Cb or Cr signal.
The conversion device according to claim 1. The edge detection means includes
When all color level difference values between color signals included in a predetermined range from between adjacent color signals are smaller than the second threshold value based on the color level difference value between adjacent color signals, the adjacent color signals are adjacent to each other. Judge between the color signals as an edge,
The conversion device according to claim 1. A conversion device for converting a video signal of a first format into a second format having a larger amount of information than the first format,
Obtaining means for obtaining a video signal of the first format;
Extraction means for sequentially extracting a plurality of adjacent color signals having the same color difference in the first format video signal as one unit;
Generating means for generating an interpolating color signal using the extracted plurality of color signals;
Output means for converting the acquired video signal of the first format into a second format based on the interpolation color signal generated by the generating means, and outputting the second format video signal;
With
The generating means includes
A discriminating means for discriminating whether or not a difference in color level between adjacent color signals at a position where the correction color signal is interpolated in the plurality of extracted color signals is equal to or less than a threshold;
A signal generating unit configured to generate the interpolation color signal using a part of the extracted color signals when the determining unit determines that the value is equal to or less than a threshold;
Having
Conversion device. The determination means includes a sixth color signal whose color level difference between adjacent fifth color signals is equal to or less than a threshold value at a position where the correction color signal is interpolated, and is one distance from the fifth color signal. Determine whether the difference in color level is below the threshold,
When the signal generation unit determines that the difference in color level between the fifth color signal and the sixth color signal is equal to or less than a threshold value, a part of the extracted color signals is used. Generating the interpolation color signal,
The conversion device according to claim 8. A conversion device for converting a video signal of a first format into a second format having a larger amount of information than the first format,
Obtaining means for obtaining a video signal of the first format;
Extraction means for sequentially extracting a plurality of adjacent color signals having the same color difference in the first format video signal as one unit;
Generating means for generating an interpolating color signal using the extracted plurality of color signals;
Output means for converting the acquired video signal of the first format into a second format based on the interpolation color signal generated by the generating means, and outputting the second format video signal;
With
The generating means includes
In the extracted plurality of color signals, the color levels of the adjacent color signals at the position where the correction color signal is interpolated are both levels indicating black.
A signal generating unit that generates the interpolation color signal using a part of the extracted color signals when the flat part detecting unit determines that the threshold value is equal to or less than a threshold;
Having
Conversion device.

Images