25-06-2012, 02:09 PM
Low power multiplier less DCT on XILINX- FPGA
[attachment=25429]
INTRODUCTION
Discrete cosine transform (DCT) is widely used transform in image processing, especially for compression.
Some of the applications of DCT involve still image compression and compression of individual video frames
Multidimensional DCT is mostly used for compression of video streams.
DCT
Discrete cosine transform is Fourier related transform similar to discrete Fourier transform but using only real numbers.
DCTs are equivalent to DFTs of roughly twice o the length operating on real data
Lower frequencies contributes with more picture information than higher frequencies does.
Computing the 2D DCT
apply 1D DCT (Vertically) to Columns
apply 1D DCT (Horizontally) to resultant Vertical DCT above. or alternatively Horizontal to Vertical.
2D-DCT contd
The 2D-DCT considered the most efficient technique in image encoding and compression schemes, being used as a standard in several applications
The DCT coefficients have been shown to be relatively uncorrelated, and this makes it possible to construct relatively simple algorithms or compressing the coefficients values
[attachment=25429]
INTRODUCTION
Discrete cosine transform (DCT) is widely used transform in image processing, especially for compression.
Some of the applications of DCT involve still image compression and compression of individual video frames
Multidimensional DCT is mostly used for compression of video streams.
DCT
Discrete cosine transform is Fourier related transform similar to discrete Fourier transform but using only real numbers.
DCTs are equivalent to DFTs of roughly twice o the length operating on real data
Lower frequencies contributes with more picture information than higher frequencies does.
Computing the 2D DCT
apply 1D DCT (Vertically) to Columns
apply 1D DCT (Horizontally) to resultant Vertical DCT above. or alternatively Horizontal to Vertical.
2D-DCT contd
The 2D-DCT considered the most efficient technique in image encoding and compression schemes, being used as a standard in several applications
The DCT coefficients have been shown to be relatively uncorrelated, and this makes it possible to construct relatively simple algorithms or compressing the coefficients values