Digital Image Processing Week V Thurdsak LEAUHATONG

Sharpening Spatial Filter First and Second Derivative Intensity profile 1 st derivative 2 nd derivative Edge

Sharpening Spatial Filter Laplacian Sharpening Laplacian sharpening results in larger intensity discontinuity near the edge.

Sharpening Spatial Filter Laplacian Sharpening Before sharpening After sharpening

Sharpening Spatial Filter Laplacian of an Image

Sharpening Spatial Filter Laplacian Mask Application: Enhance edge, line, point Disadvantage: Enhance noise Used for estimating image Laplacian or The center of the mask is positive The center of the mask is negative

Sharpening Spatial Filter Laplacian Mask

First Order Partial Derivative: Sobel operators

First Order Partial Derivative: Image Gradient Gradient magnitude A gradient image emphasizes edges

First Order Partial Derivative: Image Gradient

Spatial Domain Filtering : Spatial Domain Filtering : Mix things up ! + - A Sharpening smooth B EC D