Method and apparatus for converting a high definition image to a relatively lower definition image using wavelet transforms
AssigneeSamsung Electronics Co., Ltd.
InventorsMusa Jahanghir, Jack Chaney, Michael A. Kaufman
Life of this patent
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Abstract
A method and an apparatus for converting a high definition image to a relatively lower definition image is provided. Image data encoded with a discrete cosine transform (DCT) is decoded using an inverse wavelet transform (IDWT). A fast inverse discrete wavelet transform (FIDWT) is also provided that reduces the number of multiplication operations relative to the IDWT. Image data is also encoded using a discrete wavelet transform (DWT) and then decoded using an (IDWT).
Claims3
A method for encoding and decoding image data, the method comprising the steps of:
- encoding image data using a discrete wavelet transform (DWT) to provide DWT encoded image data;
- and
- decoding the DWT encoded image data using an inverse discrete wavelet transform (IDWT) to provide IDWT decoded image data, wherein the DWT is of the form:
- U ( x ) = 1 2 ( idct ( x ) + idct ( x + 1 ) ) idct ( x ) = f ( x ) = 1 2 ( U ( x ) + 0 )
- where idct ( x ) = 2 N ∑ u = 0 N - 1 c ( u ) F ( u ) Cos ( 2 x + 1 ) 2 N u π
- and the calculation of the IDWT is performed in a single step.
A method for encoding and decoding image data, the method comprising the steps of:
- encoding image data using a discrete wavelet transform (DWT) to provide DWT encoded image data;
- and
- decoding the DWT encoded image data using an inverse discrete wavelet transform (IDWT) to provide IDWT decoded image data;
- and
- further including the steps of interpolating the DWT encoded data, and
- decoding the DWT encoded image data using the IDWT to provide interpolated IDWT image data, wherein the IDWT is defined as:
- f ( x ) = 1 2 ( U ( x ) + V ( x ) ) f ( x + 1 ) = 1 2 ( U ( x ) - V ( x ) ) where U ( x ) = 1 2 ( idct ( x ) + idct ( x + 1 ) ) and V ( x ) = 1 2 ( idct ( x ) - idct ( x + 1 ) ) .
Dependencies are inferred from the claim text.