Filtering in the Filtering in the Frequency Domain Frequency Domain Chapter 6 Chapter 6 Dr. Mario Chacón Dr. Mario Chacón DSP & Vision Lab DSP & Vision Lab
Jan 22, 2016
Filtering in the Frequency Filtering in the Frequency DomainDomain
Chapter 6Chapter 6
Dr. Mario ChacónDr. Mario Chacón
DSP & Vision LabDSP & Vision Lab
Filtering in the Frequency DomainFiltering in the Frequency Domain
Filtering in the Frequency DomainFiltering in the Frequency Domain
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Figura 6. 2 Distintas frecuencias de corte del filtro pasa bajas.
Filtering in the Frequency DomainFiltering in the Frequency Domain Spatial filters in the frequency, Spatial filters in the frequency,
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Figura 6. 3 Ilustración de la cantidad de energía cubierta por el filtro pasa bajas con distintas frecuencias de corte.
Filtering in the Frequency DomainFiltering in the Frequency Domain Spatial filters in the frequency, Spatial filters in the frequency,
LPLP
Figura 6. 4 a) Original, b) Pasa bajas con r =0.3 c) Pasa bajas con r =0.5 y d) Pasa bajas con r =0.9.
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Figura 6. 5 Obtención de energía relacionada a un ancho de banda específico.
Filtering in the Frequency Domain Spatial filters in the frequency, LP, blurring
Figura 6. 6 Filtros pasa bajas y su correspondiente h(n), primera y segunda filas dominio de la frecuencia, tercera, en el espacio. a) Rc=0.1, b) Rc=0.5, c) Rc=0.8.
Filtering in the Frequency DomainFiltering in the Frequency Domain Spatial filters in the frequency, Spatial filters in the frequency,
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Filtering in the Frequency DomainFiltering in the Frequency Domain Spatial filters in the frequency, Spatial filters in the frequency,
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Figura 6. 7 Representación de un filtro ideal pasa altas en la frecuencia.
Filtering in the Frequency DomainFiltering in the Frequency Domain Spatial filters in the frequency, Spatial filters in the frequency,
HPHP
Figura 6. 8 a) Imagen original, Pasa altas con b) r =0.1 c) r =0.5, d) r =0.9, e)-g) imágenes procesadas con estos filtros.
Filtering in the Frequency DomainFiltering in the Frequency Domain
Pasos para realizar filtrado en la frecuencia.
1.Para trabajar con transformadas centradas multiplique la imagen de entrada y el filtro por . 2.Obtenga la DFT de , .3.Obtenga la DFT de , .4.Multiplique por .5.Obtenga 6.Obtenga la parte real de 7.Multiplique por
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Figura 6. 9 Rellenado de ceros de una imagen.
Filtering in the Frequency DomainFiltering in the Frequency DomainLineal convolution and the DFTLineal convolution and the DFT
96X128 128X128
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Figura 6. 10 a) Imagen original, Transformada de Fourier b) Sin relleno, c) 128x128, d) 96X512, e) 512x512.
Filtering in the Frequency DomainFiltering in the Frequency DomainNotch filterNotch filter
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Figura 6. 11 a) Original, b) Magnitud, c) fase.
Filtering in the Frequency DomainFiltering in the Frequency DomainNotch filterNotch filter
Figura 6. 12a) Imagen original 10 pixeles/ciclo, b) espectro, c) imagen rotada 45º,d) su espectro, e)-h) casos similares pero para 20 pixeles/ciclo y rotada a -45º.
Filtering in the Frequency DomainFiltering in the Frequency DomainNotch filterNotch filter
Figura 6. 13 a) Imagen con ruido, b) Espectro de la imagen con ruido, c) Espectro sin ruido, d) Imagen recuperada.
Filtering in the Frequency DomainFiltering in the Frequency DomainMagnitude / Phase reconstructionMagnitude / Phase reconstruction
Figura 6. 14 a) Original, b) reconstrucción sin información de fase c) reconstrucción sin información de magnitud.
Filtering in the Frequency DomainFiltering in the Frequency DomainFocus adjustmentFocus adjustment
Figura 6. 15 a) Muy fuera de foco, b) fuera de foco., c) en foco.