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.
Claims23
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, 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 bilinear 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, 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
- )
- =
- G
-
- (
- k
- ,
- l
- )
- F
-
- (
- k
- ,
- l
- )
- ,
- 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, 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
- )
- H
- *
- (
- k
- ,
- l
- )
-
- H
-
- (
- k
- ,
- l
- )
- +
- C
- *
- (
- k
- ,
- l
- )
-
- C
-
- (
- k
- ,
- l
- )
- .
A filtering control method for improving the image quality of a bilinear interpolated image when recovering a high resolution image from a low resolution image, 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 bilinear interpolated image when recovering a high resolution image from a low resolution image, 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 PST (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, 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
- )
- .
A method for generating pixel data, the method performed by at least one processor and the method comprising:
- generating a set of 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 comprising:
- selecting original pixel data,
- obtaining at least first and second filter coefficients, the first and second filter coefficients configured to interpolate the original pixel data, and the first filter coefficient comprising weighting factors having at least three at least three individual values;
- applying the first filter coefficient to the selected original pixel data to produce first interpolated original pixel data, 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;
- summing the weighted pixel data to produce the first interpolated pixel data;
- and
- applying the second filter coefficient to the first interpolated original pixel data to produce second interpolated pixel data;
- and
- generating the pixel data by performing a bit operation on the second interpolated pixel data.
A digital video system comprising:
- a low-resolution imaging system configured to capture an original image;
- and
- a processor configured to generate an interpolated image from the original image and to obtain interpolated pixel data for the interpolated image from original pixel data from the original image, wherein the interpolated pixel data for a particular pixel of the interpolated image is generated by performing operations comprising:
- selecting original pixel data for the interpolated image,
- obtaining at least first and second filter coefficients, the first and second filter coefficients configured to interpolate the original pixel data, and the first filter coefficient comprising weighting factors having at least three at least three individual values,
- applying the first filter coefficient to the selected original pixel data to produce first interpolated original pixel data, 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;
- summing the weighted pixel data to produce the first interpolated pixel data;
- applying the second filter coefficient to the first interpolated original pixel data to produce second interpolated pixel data, and
- generating the interpolated image by performing a bit operation to the second interpolated pixel data.
Dependencies are inferred from the claim text.