Alex Z Mou from Dublin, CA, age 61

Scaled Forward And Inverse Discrete Cosine Transform And Video Compression/Decompression Systems Employing The Same

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US Patent:

6694342, Feb 17, 2004

Filed:

Oct 16, 2000

Appl. No.:

09/690351

Inventors:

Alex Z. Mou - Sunnyvale CA

Assignee:

Sun Microsystems, Inc. - Santa Clara CA

International Classification:

G06F 1714

US Classification:

708402, 382250

Abstract:

A system and method of a forward and/or inverse discrete cosine transform in a video system. In one embodiment, an array of DCT transform coefficients are converted to a two dimensional array of spatial data. The array of DCT transform coefficients are first operated upon by a pre-scale computation unit (implemented in either hardware or software) which multiplies a set of predetermined pre-scale constants with the input coefficients. The pre-scale constants multiplied by the input DCT coefficient matrix form a symmetric pre-scale array. Upon pre-scaling using the symmetric pre-scale factor array, an intermediary array is composed by performing intermediary calculations upon each column vector of the pre-scaled array. The output of this intermediary calculation is composed to form an intermediary array. Subsequently, a set of calculations are performed row-wise upon each row vector of the intermediary array to thereby form the output array of spatial data.

Signal Interpolation And Decimation Exploiting Filter Symmetry

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US Patent:

6718354, Apr 6, 2004

Filed:

Feb 23, 2000

Appl. No.:

09/511569

Inventors:

Alex Zhi-Jian Mou - Sunnyvale CA

Assignee:

Sun Microsystems, Inc. - Santa Clara CA

International Classification:

G06F 717

US Classification:

708313, 708319

Abstract:

Symmetry in a filter is used to reduce the complexity of an interpolator or a decimator and to simplify derivation of resulting discrete samples. In particular, an inverse relationship between weights applied to two samples is recognized and exploited. An inverse relationship is recognized when a first weight is associated with a first of the samples and a second weight is associated with a second of the samples and a weight which is equivalent to the first weight is associated with the second sample and a weight which is equivalent to the second weight is associated with the first sample. The inverse relationship is exploited by forming two composite weights of the first and second weights and weighting composite sample signals with the composite weights. A first of the composite weights has a value which is one-half of the sum of the values of the first and second weights. A second of the composite weights has a value which is one-half of the difference of the values of the first and second weights.

Signal Interpolation And Decimation Exploiting Filter Symmetry

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US Patent:

58926933, Apr 6, 1999

Filed:

Jul 1, 1996

Appl. No.:

8/673489

Inventors:

Alex Zhi-Jian Mou - Sunnyvale CA

Assignee:

Sun Microsystems, Inc. - Palo Alto CA

International Classification:

G06F 1717

US Classification:

3647241

Abstract:

Symmetry in a filter is used to reduce the complexity of an interpolator or a decimator. A weight filter matrix which includes L=(N-1)M+K weights is divided into two sub-filters, the first having L1=NK weights and the second having L2=(N-1)(M-K). For interpolators, N source samples are applied to the first sub-filter to produce K signals and N--1 source samples are applied to the second sub-filter to produce M-K signals. For decimators, K source samples are applied to the first sub-filter to produce N samples and M-K source samples are applied to the second sub-filter to produce N-1 samples. An inverse relationship is recognized when a first weight is associated with a first of the samples and a second weight with a second of the samples and a weight equivalent to the first weight is associated with the second sample and a weight equivalent to the second weight is associated with the first sample. Two composite weights of the first and second weights and composite sample signals weighted therewith are formed. The composite weights can be used repeatedly for each subsequent interpolation or decimation and are calculated only once.

Scaled Forward And Inverse Discrete Cosine Transform And Video Compression/Decompression Systems Employing The Same

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US Patent:

6134270, Oct 17, 2000

Filed:

Jun 13, 1997

Appl. No.:

8/874382

Inventors:

Alex Z. Mou - Sunnyvale CA

Assignee:

Sun Microsystems, Inc. - Palo Alto CA

International Classification:

H01N 712
H04B 166

US Classification:

375240

Abstract:

A system and method of a forward and/or inverse discrete cosine transform in a video system. In one embodiment, an array of DCT transform coefficients are converted to a two dimensional array of spatial data. The array of DCT transform coefficients are first operated upon by a pre-scale computation unit (implemented in either hardware or software) which multiplies a set of predetermined pre-scale constants with the input coefficients. The pre-scale constants multiplied by the input DCT coefficient matrix form a symmetric pre-scale array. Upon pre-scaling using the symmetric pre-scale factor array, an intermediary array is composed by performing intermediary calculations upon each column vector of the pre-scaled array. The output of this intermediary calculation is composed to form an intermediary array. Subsequently, a set of calculations are performed row-wise upon each row vector of the intermediary array to thereby form the output array of spatial data.

Signal Interpolation And Decimation Exploiting Filter Symmetry

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US Patent:

59566663, Sep 21, 1999

Filed:

Jul 1, 1996

Appl. No.:

8/674687

Inventors:

Alex Zhi-Jian Mou - Sunnyvale CA

Assignee:

Sun Microsystems, Inc. - Palo Alto CA

International Classification:

G06G 712

US Classification:

702190

Abstract:

Symmetry in a filter is used to reduce the complexity of an interpolator or a decimator and to simplify derivation of resulting discrete samples. In particular, an inverse relationship between weights applied to two samples is recognized and exploited. An inverse relationship is recognized when a first weight is associated with a first of the samples and a second weight is associated with a second of the samples and a weight which is equivalent to the first weight is associated with the second sample and a weight which is equivalent to the second weight is associated with the first sample. The inverse relationship is exploited by forming two composite weights of the first and second weights and weighting composite sample signals with the composite weights. A first of the composite weights has a value which is one-half of the sum of the values of the first and second weights. A second of the composite weights has a value which is one-half of the difference of the values of the first and second weights.

Signal Interpolation And Decimation Exploiting Filter Symmetry

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US Patent:

62566547, Jul 3, 2001

Filed:

Jul 1, 1996

Appl. No.:

8/672531

Inventors:

Alex Zhi-Jian Mou - Sunnyvale CA

Assignee:

Sun Microsystems, Inc. - Palo Alto CA

International Classification:

G06F 1717

US Classification:

708313

Abstract:

Symmetry in a filter is used to reduce the complexity of an interpolator or a decimator and to simplify derivation of resulting discrete samples. In particular, an inverse relationship between weights applied to two samples is recognized and exploited. An inverse relationship is recognized when a first weight is associated with a first of the samples and a second weight is associated with a second of the samples and a weight which is equivalent to the first weight is associated with the second sample and a weight which is equivalent to the second weight is associated with the first sample. The inverse relationship is exploited by forming two composite weights of the first and second weights and weighting composite sample signals with the composite weights. A first of the composite weights has a value which is one-half of the sum of the values of the first and second weights. A second of the composite weights has a value which is one-half of the difference of the values of the first and second weights.

Signal Interpolation And Decimation Exploiting Filter Symmetry

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US Patent:

62266624, May 1, 2001

Filed:

Apr 1, 1999

Appl. No.:

9/285807

Inventors:

Alex Zhi-Jian Mou - Sunnyvale CA

Assignee:

Sun Microsystems, Inc. - Palo Alto CA

International Classification:

G06F 1717

US Classification:

708313

Abstract:

Symmetry in a filter is used to reduce the complexity of an interpolator or a decimator and to simplify derivation of resulting discrete samples. In particular, a weight filter matrix which includes L=(N-1)M+K weights is divided into two sub-filters, the first having L1=NK weights and the second having L2=(N-1)(M-K). In the case of interpolators, N source samples are applied to the first weight sub-filter to produce K interpolated signals and N-1 source samples are applied to the second weight sub-filter to produce M-K interpolated signals. In the case of decimators, K source samples are applied to the first weight sub-filter to produce N decimated sample components and M-K source samples are applied to the second weight sub-filter to produce N-1 decimated sample components. If the weight filter matrix is centrosymmetric, both sub-filters are also centrosymmetric. Symmetry in the weights of each sub-filter is recognized and exploited.