Filtering control method for improving image quality of bi-linear interpolated image
AssigneeLG Electronics Inc.
InventorsMin-Cheol Hong, Yoon-Seong Soh
Life of this patent
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Abstract
The present invention relates to an interpolation method for enlarging a digital image or predicting a moving vector of a compressed image system as a sub-pixel unit when the image digitized through a CCD (Charge Coupled Device) camera ect. has a low resolution in a video phone or video conference or general digital video system, particularly the present invention can be adapted to a post processor of a compressed digital image in order to improve the image quality, and can be used for finding a moving vector of a moving picture compressed type, accordingly the present invention is capable of improving the image quality.
Claims24
A filtering control method for improving the image quality of a bi-linear interpolated image when recovering a high resolution image from a low resolution image, the method comprising performing operations using at least one processor, the operations comprising:
- restoring a requested high resolution image f by finding an added filter coefficient Q of a PSF(P) and a bi-linear interpolation filter B from an equation f=Pg=PBz=Qz, wherein f is the high resolution image as requested, P is the PSF (Point Spread Function), g is the high resolution image found by the bi-linear interpolation method, and z is the low resolution image;
- wherein the high resolution image f can be restored by performing an added function M(f) definition process for finding the PSF(H) from an equation g=Bz=Hf+n, wherein B, H are bi-linear interpolation filters, and n is a noise component generated by the assumed H;
- and
- wherein the added function M(f) is defined as M(f)=∥g−Hf∥2+α∥Cf∥2, wherein α is a regularization parameter, and C is a two-dimensional high frequency filter for finding mitigation of the original image.
A filtering control method for improving the image quality of a bi-linear interpolated image when recovering a high resolution image from a low resolution image, the method comprising performing operations using at least one processor, the operations comprising:
- restoring a requested high resolution image f by finding an added filter coefficient Q of a PSF(P) and a bi-linear interpolation filter B from an equation f=Pg=PBz=Qz, wherein f is the high resolution image as requested, P is the PSF (Point Spread Function), g is the high resolution image found by the bi-linear interpolation method, and z is the low resolution image;
- wherein the high resolution image f can be restored by performing an added function M(f) definition process for finding the PSF(H) from an equation g=Bz=Hf+n, wherein B, H are bi-linear interpolation filters, and n is a noise component generated by the assumed H;
- wherein the high resolution image f is restored by finding a PSF(P) of a f=Pg function after finding the PSF(H) from the added function M(f);
- and
- wherein the PSF(H) is found by using an equation
- H
-
- (
- k
- ,
- l
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- =
- G
-
- (
- k
- ,
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- F
-
- (
- k
- ,
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- .
- G(k,l) is the component in the k,l frequency region of the bi-linear interpolated image, and F(k,l) is the component in the k,l frequency region of the high resolution image.
A filtering control method for improving the image quality of a bi-linear interpolated image when recovering a high resolution image from a low resolution image, the method comprising performing operations using at least one processor, the operations comprising:
- restoring a requested high resolution image f by finding an added filter coefficient Q of a PSF(P) and a bi-linear interpolation filter B from an equation f=Pg=PBz=Qz, wherein f is the high resolution image as requested, P is the PSF (Point Spread Function), g is the high resolution image found by the bi-linear interpolation method, and z is the low resolution image;
- wherein the PSF(P) can be found by getting an IFT (Inverse Fourier Transform) by an equation
- P
-
- (
- k
- ,
- l
- )
- =
- H
- *
- (
- k
- ,
- l
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- H
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- (
- k
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-
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-
- (
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- +
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- (
- k
- ,
- l
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- C
-
- (
- k
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- l
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- H(k,l) is a component in the k,l frequency region of the PSF(H), and C is a two-dimensional high frequency filter.
A filtering control method for improving the image quality of a bi-linear interpolated image when recovering a high resolution image from a low resolution image, the method comprising performing operations using at least one processor the operations comprising:
- defining an added function M(f) for finding a PSF(H) from an equation g=Bz=Hf+n (wherein B, H are bi-linear filters, n is a noise component generated by an assumed H when the H is a PSF (Point Spread Function), f is a requested high resolution image, z is a low resolution image, and g is a high resolution image gotten by the bi-linear interpolation method);
- finding a PSF(P) of a f=Pg function after finding the PSF (H) from the defined added function M(f);
- and
- restoring the requested high resolution image f by finding an added filter coefficient Q of the PSF(P) and interpolation filter B from the equation f=Pg=PBZ=Qz;
- wherein the added function M(f) is defined as M(f)=∥g−Hf∥2+α∥Cf∥2, wherein α is a regularization parameter, and C is a two-dimensional high frequency filter for finding the mitigation of the original image.
A filtering control method for improving the image quality of a bi-linear interpolated image when recovering a high resolution image from a low resolution image, the method comprising performing operations using at least one processor the operations comprising:
- defining an added function M(f) for finding a PSF(H) from an equation g=Bz=Hf+n (wherein B, H are bi-linear filters, n is a noise component generated by an assumed H when the H is a PSF (Point Spread Function), f is a requested high resolution image, z is a low resolution image, and g is a high resolution image gotten by the bi-linear interpolation method);
- finding a PSF(P) of a f=Pg function after finding the PSF (H) from the defined added function M(f);
- and
- restoring the requested high resolution image f by finding an added filter coefficient Q of the PSF(P) and interpolation filter B from the equation f=Pg=PBZ=Qz;
- wherein the PSF(H) is found by an equation
- H(k,l)=(G(k,l)/F(−k,l),
- wherein G(k,l) is the component in the k,l frequency region of the bi-linear interpolated image, and F(k,l) is the component in the k,l frequency region of the high resolution image.
A filtering control method for improving the image quality of a bi-linear interpolated image when recovering a high resolution image from a low resolution image, the method comprising performing operations using at least one processor, the operations comprising:
- defining an added function M(f) for finding a PSF(H) from an equation g=Bz=Hf+n (wherein B, H are bi-linear filters, n is a noise component generated by an assumed H when the H is a PSF (Point Spread Function), f is a requested high resolution image, z is a low resolution image, and g is a high resolution image gotten by the bi-linear interpolation method);
- finding a PSF(P) of a f=Pg function after finding the PSF(H) from the defined added function M(f);
- and
- restoring the requested high resolution image f by finding an added filter coefficient Q of the PSF(P) and interpolation filter B from the equation f=Pg=PBZ=Qz;
- wherein the PSF(P) is found by using an IFT (Inverse Fourier Transform) by an equation
- P
-
- (
- k
- ,
- l
- )
- =
- H
- *
- (
- k
- ,
- l
- )
- H
- *
- (
- k
- ,
- l
- )
-
- H
-
- (
- k
- ,
- l
- )
- +
- C
- *
- (
- k
- ,
- l
- )
-
- C
-
- (
- k
- ,
- l
- )
- H(k,l) is a component in the k,l frequency region of the PSF(H), and C is a two-dimensional high frequency filter.
A method for generating an interpolated pixel data, the method comprising generating a set of the interpolated pixel data from a set of original pixel data from an original image, wherein interpolated pixel data for a particular pixel is generated by performing operations using at least one processor, the operations comprising:
- selecting original pixel data for more than three pixels of the original image;
- obtaining at least a first filter coefficient and a second filter coefficient, the first filter coefficient and the second filter coefficient being configured to interpolate the original pixel data;
- applying the first filter coefficient to the selected original pixel data to produce first interpolated pixel data, the first filter coefficient including weighting factors having at least three different numerical values, wherein applying the first filter coefficient to the selected original pixel data comprises:
- multiplying each of the weighting factors and the selected original pixel data to produce weighted pixel data, and
- summing the weighted pixel data to produce the first interpolated pixel data;
- multiplying the second filter coefficient and the first interpolated pixel data to produce second interpolated pixel data;
- and
- identifying the interpolated pixel data as the second interpolated pixel data.
A method for a moving picture compression with a video system by generating an interpolated pixel data, the method comprising:
- generating a set of interpolated pixel data from a set of original pixel data from an original image;
- and
- finding a sub-pixel motion vector using the set of interpolated pixel data,
- wherein interpolated pixel data for a particular pixel is generated by performing operations using the video system, the operations comprising:
- selecting, by the video system, original pixel data including more than three pixels of the original image;
- obtaining, by the video system, at least a first filter coefficient and a second filter coefficient, the first filter coefficient and the second filter coefficient being configured to interpolate the original pixel data;
- applying, by the video system, the first filter coefficient to the selected original pixel data to produce first interpolated pixel data, the first filter coefficient including weighting factors having at least three different numerical values, the at least three different numerical values including integer values, wherein said applying the first filter coefficient to the selected original pixel data comprises:
- multiplying each of the weighting factors and the selected original pixel data to produce weighted pixel data, and
- summing the weighted pixel data to produce the first interpolated pixel data;
- applying, by the video system, the second filter coefficient to the first interpolated pixel data to produce second interpolated pixel data, wherein said applying the second filter coefficient comprises multiplying the second filter coefficient and the first interpolated pixel data and summing results of multiplying the second filter coefficient and the first interpolated pixel data to produce the second interpolated pixel data;
- and
- identifying, by the video system, the interpolated pixel data for the particular pixel as the second interpolated pixel data.
Dependencies are inferred from the claim text.