Haralick Texture

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Image texture is a quantification of the spatial variation of grey tone values. Haralick
 
Image texture is a quantification of the spatial variation of grey tone values. Haralick
et al. (1973) presented texture measures that may be derived by comparing the values
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et al. (1973) suggested the use  of gray level co-occurrence matrices (GLCM). This method is based on the joint probability distributions of pairs of pixels. GLCM show how often  each  gray  level  occurs  at  a pixel  located  at  a fixed  geometric  position  relative  to  each  other  pixel, as  a function of the gray level (Srinivasan and Shobha 2008). An essential component is the definition of eight nearest-neighbor resolution cells (Fig.) that define different matrices for different angles (0°,45°,90°,135°) and distances between the horizontal neighboring pixels. uggested  the use of gray  level  co-occurrence matrices(GLCM) 
of the digital numbers within a window. An essential component of the concept of
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the Haralick texture measures is the definition of eight nearest-neighbor resolution cells
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(Fig.). Now we may define different matrices for different angles (0°,45°,90°,135°) and
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distances between the horizontal neighboring pixels.
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Many studies in land cover and forest type classification utilize textural features to
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improve the classification accuracies.
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We use the ASTER satellite band number 1 (green) and an inter-pixel sampling distance
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of one. At first we need to linearly transform the 16-bit ASTER data to 8-bit radiometric
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resolution.
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[[File:Texture.png|center|500px|thumb|3x3 window definition and spatial  relationship for calculating Haralick texture measures. Pixel 1 and 5  are 0° (horizontal) nearest neighbors to the center pixel * ; pixel 2  and 6 are 135° nearest neighbors; pixels 3 and 7 are 90° nearest  neighbors, pixel 4 and 8 are 45° nearest neighbors to the center pixel *  (Haralick et al. 1973)]]
 
[[File:Texture.png|center|500px|thumb|3x3 window definition and spatial  relationship for calculating Haralick texture measures. Pixel 1 and 5  are 0° (horizontal) nearest neighbors to the center pixel * ; pixel 2  and 6 are 135° nearest neighbors; pixels 3 and 7 are 90° nearest  neighbors, pixel 4 and 8 are 45° nearest neighbors to the center pixel *  (Haralick et al. 1973)]]
  
  
 
[[category:Spatial Filtering]]
 
[[category:Spatial Filtering]]

Revision as of 22:16, 18 November 2017

Image texture is a quantification of the spatial variation of grey tone values. Haralick et al. (1973) suggested the use of gray level co-occurrence matrices (GLCM). This method is based on the joint probability distributions of pairs of pixels. GLCM show how often each gray level occurs at a pixel located at a fixed geometric position relative to each other pixel, as a function of the gray level (Srinivasan and Shobha 2008). An essential component is the definition of eight nearest-neighbor resolution cells (Fig.) that define different matrices for different angles (0°,45°,90°,135°) and distances between the horizontal neighboring pixels. uggested the use of gray level co-occurrence matrices(GLCM)

3x3 window definition and spatial relationship for calculating Haralick texture measures. Pixel 1 and 5 are 0° (horizontal) nearest neighbors to the center pixel * ; pixel 2 and 6 are 135° nearest neighbors; pixels 3 and 7 are 90° nearest neighbors, pixel 4 and 8 are 45° nearest neighbors to the center pixel * (Haralick et al. 1973)
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