JP2002171535A - Image processor, image processing method and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor that can obtain a video signal at a 4:2:2 rate close to an original resolution in the case of restoring a video signal at a 4:4:4 rate generated by interpolating the video signal at the 4:2:2 rate into the video signal at the 4:4:2 rate again. SOLUTION: The video signal at a 4:2:2:4 rate received in a step S1 is converted into a video signal at a 4:4:4:4 rate. Processing such as colored spot light effect and trail effect including color change is applied to the video signal at the 4:4:4:4 rate in a step S2. After eliminating a high frequency component of color difference signals U, V from the video signal at the 4:4:4:4 rate in a step S3, each of the color difference signals U, V is alternately interleaved at an interval of one pixel to restore the video signal at the 4:4:4:4 rate to the video signal at the 4:2:2:4 rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing apparatus and method, and a recording medium. For example, the present invention relates to a 4: 2: 2 rate video signal obtained by interpolating a color difference signal among 4: 2: 2 video signals.
An image processing apparatus and method suitable for returning a 4: 4 rate video signal back to a 4: 2: 2 rate video signal,
And a recording medium.

[0002]

2. Description of the Related Art Digital Storag
The advent of e) has greatly contributed to the technological progress in the production of television programs. Of digital storage
The recording capacity of a DRAM (Dynamic Random Access Memory) has been gradually increased so that one scanning line, one field image, one frame image, and a series of plural images can be recorded. Was. Further, even if its manufacturing cost, circuit scale, power consumption, etc. are taken into consideration, it is economically practical.

As an application example of a digital storage such as a DRAM, it is used when an image is deformed or moved to an arbitrary shape at the time of producing a television program or the like.
A so-called DME (Digital Multi Effects) can be mentioned.

In a conventional DME or the like, a 10-bit width luminance signal Y and a 10-bit width color difference signal C (color difference signals U,
V are alternately arranged), and the 4: 2: 2 rate video signal is processed as it is, so that the following problem occurs.

That is, since the geometrical positions of the color difference signals U and V corresponding to the luminance signal Y are shifted, there is a problem that the memory in which the video signal is recorded cannot be used efficiently. In addition, since the spatial frequency of the luminance signal Y and the spatial frequency of the color difference signals U and V are different, there is a problem that it is not possible to perform a special effect process related to a color operation such as a colored spotlight effect or a color-change trail effect.

In order to solve these problems, the applicant of the present invention converts a 4: 2: 2 rate video signal into a 10-bit wide luminance signal Y, an 8-bit wide color difference signal U, and an 8-bit wide color difference signal. A technology for converting a V signal into a 4: 4: 4 rate video signal has already been proposed as Japanese Patent Application No. 2000-292314.

[0007]

[0005] By the way, if a device after the DME does not support 4: 4: 4 rate video signal, the video signal converted to 4: 4: 4 rate and processed is kept as it is. Therefore, it is necessary to return to the original 4: 2: 2 rate video signal.

The 4: 4: 4 rate video signal can be returned to the 4: 2: 2 rate video signal by thinning out the color difference signals U and V to 1/2, respectively. Since the information amount is reduced to an 8-bit width, there is a problem that the resolution is inferior to the original 10-bit color difference signals U and V.

The present invention has been made in view of such circumstances, and a 4: 4: 4 rate video signal generated by interpolating a 4: 2: 2 rate video signal is again converted to a 4: 2: 2 rate video signal. An object of the present invention is to obtain a 4: 2: 2 rate video signal close to the original resolution by performing a thinning process after removing a high-frequency component using a low-pass filter when returning to a video signal.

[0010]

According to the present invention, there is provided an image processing apparatus comprising: input means for inputting a first video signal having different spatial frequencies of a luminance signal and a color difference signal;
Separating means for separating a color difference signal from a video signal, and interpolating a color difference signal corresponding to a predetermined position using a plurality of continuous color difference signals separated by the separating means, and a spatial frequency of a luminance signal and a spatial frequency of the color difference signal are equal. Generating means for generating a second video signal, digital image processing means for performing digital image processing on the second video signal generated by the generating means, and a second video signal processed by the digital image processing means as a luminance signal. A conversion unit configured to convert a color difference signal into a third video signal having a different spatial frequency; a conversion unit configured to remove a high frequency component of the color difference signal included in the second video signal; And a thinning means for thinning out the color difference signal from which the color difference signal has been removed.

The first and third video signals may be 4: 2: 2 video signals composed of a luminance signal Y, a color difference signal U, and a color difference signal V, and the second video signal Are the luminance signal Y, the color difference signal U, and the color difference signal V
4: 4: 4 video signal.

According to the image processing method of the present invention, an input step of inputting a first video signal having different spatial frequencies of a luminance signal and a color difference signal, and a color difference signal from the first video signal input in the input step processing. A second video signal in which the spatial frequency of the luminance signal is equal to the spatial frequency of the color difference signal by interpolating the color difference signal corresponding to a predetermined position using the separation step of separating and the plurality of continuous color difference signals separated in the processing of the separation step A digital image processing step of performing digital image processing on the second video signal generated in the processing of the generating step, and converting the second video signal processed by the digital image processing step into a luminance signal. Converting the signal and the color difference signal into a third video signal having different spatial frequencies. The conversion step includes the step of converting the color difference signal included in the second video signal. Characterized in that it comprises a removal step of removing the frequency components, and a thinning-out step for thinning the color difference signal frequency components are removed in the process of removal step.

[0013] The program of the recording medium according to the present invention comprises an input step of inputting a first video signal having different spatial frequencies of a luminance signal and a color difference signal, and a color difference signal from the first video signal input in the processing of the input step. A second image in which the spatial frequency of the luminance signal is equal to the spatial frequency of the color difference signal by interpolating the color difference signal corresponding to a predetermined position using a plurality of continuous color difference signals separated in the processing of the separation step. A generating step of generating a signal, a digital image processing step of performing digital image processing on the second video signal generated by the processing of the generating step, and a second video signal processed by the digital image processing step. Converting the luminance signal and the color-difference signal into a third video signal having different spatial frequencies. Characterized in that it comprises a removal step for removing high-frequency components of the signal, and a thinning-out step for thinning the color difference signal frequency components are removed in the process of removal step.

According to the image processing apparatus and method of the present invention, and a program for a recording medium, a first video signal having different spatial frequencies of a luminance signal and a chrominance signal is input, and a chrominance signal is converted from the input first video signal. Are separated, the color difference signals corresponding to the predetermined positions are interpolated using the separated continuous color difference signals, and a second video signal having the same spatial frequency of the luminance signal and the color difference signal is generated. Further, the generated second video signal is subjected to digital image processing, and the digital image processed second video signal is converted into a third video signal having different spatial frequencies of a luminance signal and a color difference signal. . In the conversion process, the high-frequency component of the color difference signal included in the second video signal is removed, and the color difference signal from which the high-frequency component has been removed is thinned out.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An image synthesizing apparatus to which the present invention is applied will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration example of an image composition device. This image synthesizing apparatus is used, for example, when producing a television broadcast program, and synthesizes a video of video input A and a video of video input B which have been subjected to digital image processing such as deformation and movement. Output.

The image synthesizing apparatus detects a user operation and outputs a corresponding operation signal to a control circuit 2 by controlling a lever arm 1, a drive 5, a magnetic disk 6 (including a floppy disk), and an optical disk 7 (CD). -ROM (Compact Disc-
Read Only Memory), DVD (including Digital Versatile Disc), magneto-optical disk 8 (including MD (Mini Disc)),
Alternatively, the control circuit 2 that reads the control program stored in the semiconductor memory 9 and controls the entire image synthesizing apparatus based on the read control program, the operation signal from the lever arm 1, and the like, and the video input A It comprises a DME 3 for performing digital image processing and outputting to the synthesizing circuit 4, and a synthesizing circuit 4 for superimposing the video of video input A on which the digital image processing has been performed on the video of video input B and outputting it to the subsequent stage.

The video input A input to the DME 3 is 4:
2: 2: 4 rate HD format (eg, 108
0i × 1920) video signal (30-bit width), that is, a 10-bit width luminance signal Y, a 10-bit width color difference signal C (color difference signals U and V are alternately inverted), and a 10-bit width. Is assumed to be a video signal composed of the key signal K. The video input A is HD (High Defi
nition) format video signal and SD (Standard D)
efinition) format video signal (for example, 480i
× 720) and video signals of other formats.

Next, the operation of the image synthesizing apparatus will be described. The video of the video input A is subjected to digital image processing corresponding to a user operation on the lever arm 1 by the DME 3, supplied to the synthesizing circuit 4, and superimposed on the video of the video input B by the synthesizing circuit 4 and output.

FIG. 2 shows a configuration example of the DME 3. DME
Reference numeral 3 denotes an input 4: 2: 2: 4 rate video signal,
An up-sampling processing unit 11 for converting into a 4: 4: 4 rate video signal, a colored spotlight effect and a trail effect with color change for the 4: 4: 4: 4 rate video signal supplied from the up-sampling processing unit 11 Effect processing unit 12 that performs processing such as
4: 2: 4: 4 rate video signal supplied from 2 is passed through a built-in 1: 2: 1 low-pass filter, and 4: 2:
It is composed of a down-sampling processor 13 for converting into a 2: 4 rate video signal.

The operation of the DME 3 will be described with reference to the flowchart of FIG. In step S1, the up-sampling processing section 11 inputs the input 4: 2: 2:
The 4-rate video signal is converted into a 4: 4: 4: 4 rate video signal. This will be specifically described.

FIG. 4A shows a video signal input to the upsampling processor 11 in the order of horizontal scanning. That is, at a certain timing, the 10-bit width luminance signal Y0, the 10-bit width color difference signal U0, and the key signal K0 corresponding to the pixel P0 are simultaneously input to the up-sampling processing unit 11. In the next clock, 1 corresponding to the pixel P1 located to the right of the pixel P0
0-bit width luminance signal Y1, 10-bit width color difference signal V
1, and the key signal K1 are input simultaneously. In the next clock, the pixel P located on the right of the pixel P1
2, a 10-bit width luminance signal Y2, a 10-bit width color difference signal U2, and a key signal K2 are simultaneously input.

The up-sampling processing section 11 includes:
The color difference signal C not present in the 2: 2: 4 rate video signal is
By interpolating using a plurality of color difference signals existing before and after that, a 4: 4: 4: 4 rate image in which the spatial frequencies of the luminance signal Y and the color difference signals U and V are equal as shown in FIG. The signal is converted into a signal and output to the special effect processing unit 12.

For example, the non-existent color difference signal U3 corresponding to the pixel P3 is replaced with the existing color difference signals U0, U2, U4, U
6 to interpolate. For example, the absent color difference signal V4 corresponding to the pixel P4 is replaced with the existing color difference signals V1, V
Interpolation is performed using 3, V5, and V7. Color difference signal U3 = aU0 + bU2 + cU4 + dU6 Color difference signal V4 = aV1 + bV3 + cV5 + dV7 where a to d are predetermined interpolation coefficients.

Further, the upsampling processor 11
Is obtained by rounding off the information amount of the color difference signals U and V in the 4: 4: 4: 4 rate video signal obtained by interpolation.
Reduce from 0 bit width to 8 bit width. Note that, of the video signals, the luminance signal Y and the key signal K are
The bit width is output to the special effect processing unit 12 while maintaining the bit width.

In step S2, the special effect processing unit 1
2: 4: 4 from the upsampling processing unit 11:
The 4: 4 rate video signal is subjected to processes such as a colored spotlight effect and a color-changed trail effect, and is output to the downsampling processing unit 13.

In step S3, the down-sampling processing unit 13 uses the built-in 1: 2: 1 low-pass filter to input 4: 4:
After removing the high frequency components of the color difference signals U and V from the 4: 4 rate video signal, the color difference signals U and V are alternately thinned out every other pixel as shown in FIG. The spatial frequency is returned to の of the spatial frequency of the luminance signal Y, and the information amount is restored to a 10-bit width and output to the subsequent stage. The luminance signal Y and the key signal K of the video signal are output to the subsequent stage while maintaining the 10-bit width as it is.

Next, the effect of the downsampling processor 13 on 4: 4: 4: 4 rate video signals will be described with reference to FIGS. In the 4: 4: 4: 4 rate video signal input to the downsampling processing unit 13, the upsampling processing unit 11 reduces the information amount of the color difference signals U and V from 10-bit width to 8-bit width. . Therefore, the gradation change is more discontinuous than the gradation change in the original 10-bit width state. FIG. 5A illustrates an example of a gradation change of the color difference signals U and V in the 4: 4: 4: 4 rate video signal input to the downsampling processing unit 13.

As shown in FIG. 5 (A), the color difference signals U and V for changing the gradation are simply converted by the down-sampling processing unit 13 without removing high-frequency components by a 1: 2: 1 low-pass filter. When only the decimation process is performed to return the spatial frequency of the color difference signals U and V to 、,
The gradation change of the color difference signals U and V in the obtained 4: 2: 2: 4 rate video signal has a high possibility that the discontinuous waveform is held as shown in FIG. 5B. Conceivable.

However, as shown in this embodiment, the color difference signals U and V for changing the gradation as shown in FIG.
In the down-sampling processing unit 13 is 1: 2:
After removing high frequency components by one low pass filter,
That is, the color difference signals U,
When the spatial frequency is returned to し て by performing a process to change the gradation as shown in FIG. 6A using V and then performing a thinning process, the obtained 4: 2: The gradation of the color difference signals U and V in the 2: 4 rate video signal is shown in FIG.
As shown in FIG. 5, the gradation changes more continuously than the gradation change shown in FIG.

The downsampling processing unit 1 as described above
According to the effect 3, it is possible to improve the image quality by the interpolation effect with respect to the deterioration of the color component caused by the bit reduction or the like.

It should be noted that the present invention can be applied to any equipment that processes video signals.

Incidentally, the above-described series of processing can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software can execute various functions by installing a computer built into dedicated hardware or installing various programs. It is installed from a recording medium into a possible general-purpose personal computer or the like.

As shown in FIG. 1, the recording medium is a magnetic disk 6 (including a floppy disk) on which a program is recorded and an optical disk 7 which are distributed separately from a computer to provide the user with the program. (CD-R
OM (Compact Disc-Read Only Memory), DVD (Digital Vers
atile Disc), magneto-optical disc 8 (MD (Mini D
isc)), or is provided to the user in a state of being incorporated in a computer in advance as well as being constituted by a package medium including the semiconductor memory 9 or the like.
It is composed of a ROM or hard disk in which programs are recorded.

In this specification, the steps for describing the program recorded on the recording medium are not limited to the processing performed in chronological order according to the described order, but are not necessarily performed in chronological order. Alternatively, it also includes individually executed processing.

[0035]

As described above, according to the image processing leaving method and the recording medium program of the present invention, the second video signal subjected to the digital image processing is converted to the third video signal having different spatial frequencies of the luminance signal and the color difference signal. In the conversion process, the high-frequency component of the color difference signal included in the second video signal is removed, and the color difference signal from which the high-frequency component has been removed is thinned out, so that 4: 2: 2 When the 4: 4: 4 rate video signal generated by interpolating the rate video signal is returned to the 4: 2: 2 rate video signal again, the 4: 2: 2 rate video signal close to the original resolution is converted. It is possible to obtain.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an image composition device to which the present invention has been applied.

FIG. 2 is a block diagram illustrating a configuration example of a DME 3.

FIG. 3 is a flowchart illustrating an operation of the DME 3.

FIG. 4 is a diagram for explaining the operation of the DME 3.

FIG. 5 is a diagram for explaining the effect of the operation of the downsampling processing unit 13;

FIG. 6 is a diagram for explaining the effect of the operation of the downsampling processing unit 13;

[Explanation of symbols]

1 lever arm, 2 control circuit, 3 DME, 4
Synthesis circuit, 5 drive, 6 magnetic disk,
7 optical disk, 8 magneto-optical disk, 9 semiconductor memory, 11 upsampling processing unit, 12 special effects processing unit, 13 downsampling processing unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C023 AA02 AA04 AA37 DA04 5C057 AA01 AA11 BA13 BB01 CE03 DA06 DA13 DC09 EA02 EA07 EJ02 EL01 GC01

Claims (4)

[Claims] 1. An image processing apparatus for performing digital image processing on a video signal including at least a luminance signal and a color difference signal, wherein the first luminance signal and the color difference signal have different spatial frequencies.
Input means for inputting the video signal of the following, separating means for separating the color difference signal from the first video signal input by the input means, and a predetermined signal using the plurality of continuous color difference signals separated by the separating means. Generating means for interpolating a chrominance signal corresponding to the position of, and generating a second video signal having the same spatial frequency of the luminance signal and the chrominance signal, and generating the second video signal by the generating means. Digital image processing means for performing digital image processing; and conversion means for converting the second video signal processed by the digital image processing means into a third video signal having different spatial frequencies of the luminance signal and the color difference signal. Wherein the conversion unit includes: a removal unit that removes a high-frequency component of the color difference signal included in the second video signal; and before the removal unit removes the high-frequency component. An image processing apparatus, comprising: a thinning unit that thins out a color difference signal. 2. The first and third video signals are 4: 2: 2 video signals including a luminance signal Y, a color difference signal U, and a color difference signal V, and the second video signal is The image processing apparatus according to claim 1, wherein the image processing apparatus is a 4: 4: 4 video signal including a luminance signal Y, a color difference signal U, and a color difference signal V. 3. An image processing method of an image processing apparatus for performing digital image processing on a video signal including at least a luminance signal and a color difference signal, wherein the first luminance signal and the color difference signal have different spatial frequencies.
An input step of inputting a video signal of the following; a separation step of separating the color difference signal from the first video signal input in the processing of the input step; Generating a second video signal having the same spatial frequency of the luminance signal and the color difference signal by interpolating a color difference signal corresponding to a predetermined position using the color difference signal; A digital image processing step of performing the digital image processing on the second video signal; and converting the second video signal processed by the digital image processing step to the spatial frequency of the luminance signal and the color difference signal. And a converting step of converting the color difference signal included in the second video signal into a different third video signal. Image processing method characterized by comprising a removing step of removing high frequency components, and a thinning-out step for thinning the color difference signal frequency components are removed in the process of the removal step. 4. An image processing program for performing digital image processing on a video signal including at least a luminance signal and a color difference signal, wherein the luminance signal and the color difference signal have different spatial frequencies.
An input step of inputting a video signal of the following; a separation step of separating the color difference signal from the first video signal input in the processing of the input step; Generating a second video signal having the same spatial frequency of the luminance signal and the color difference signal by interpolating a color difference signal corresponding to a predetermined position using the color difference signal; A digital image processing step of performing the digital image processing on the second video signal; and converting the second video signal processed by the digital image processing step to the spatial frequency of the luminance signal and the color difference signal. And a converting step of converting the color difference signal included in the second video signal into a different third video signal. A removal step of removing high frequency components, a recording medium readable program computer, which comprises a decimation step of decimating the chrominance signal a high frequency component is removed by the process of said removing step is recorded.