08_ffilterx

08_ffilterx - H ( u , v ): a filter transfer function g (...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Frequency-Domain Filters COMP344 COMP344 Frequency-Domain Filters
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Filtering in Frequency Domain One image, two representations f ( x , y ): spatial (a collection of pixels) F ( u , v ): frequency (rate of change of intensity values or grey level) COMP344 Frequency-Domain Filters
Background image of page 2
Continuous Convolution Convolution of f and g : ( f * g )( t ) = R b a f ( τ ) g ( t - τ ) d τ often a = -∞ and b = + ( demo1 ) ( demo1 ) COMP344 Frequency-Domain Filters
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Discrete Convolution ( f * g )( t ) = R b a f ( τ ) g ( t - τ ) d τ Discrete convolution : ( f * g )( m ) = N n =1 f ( n ) g ( m - n ) ( demo ) COMP344 Frequency-Domain Filters
Background image of page 4
Convolution Theorem f ( x , y ) * h ( x , y ) F ( u , v ) H ( u , v ) the Fourier transform of a convolution is the product of the Fourier transforms COMP344 Frequency-Domain Filters
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Filtering in Frequency Domain
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: H ( u , v ): a filter transfer function g ( x , y ) = f ( x , y ) * h ( x , y ) G ( u , v ) = H ( u , v ) F ( u , v ) (element-by-element multiplication) g ( x , y ) = F-1 { G ( u , v ) } COMP344 Frequency-Domain Filters Example: Lowpass Filter Reduce the high-frequency content – blurring or smoothing COMP344 Frequency-Domain Filters Example: Highpass Filter Increase the magnitude of high-frequency components relative to low-frequency components – sharpening COMP344 Frequency-Domain Filters...
View Full Document

Page1 / 8

08_ffilterx - H ( u , v ): a filter transfer function g (...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online