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interimage:attributes_description [2010/06/23 13:42] castejon |
interimage:attributes_description [2010/06/23 16:44] tkorting |
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===== Shape Attributes ===== | ===== Shape Attributes ===== | ||
- | * area: Returns the area of the given polygon, in number of pixels. | + | * **area**: Returns the area of the given polygon, in number of pixels. |
- | * bBoxArea: Returns the bounding box area of the given polygon, in number of pixels. | + | * **bBoxArea**: Returns the bounding box area of the given polygon, in number of pixels. |
- | * perimeter: Returns the perimeter of the polygon, considering the amount of pixels in its border. | + | * **perimeter**: Returns the perimeter of the polygon, considering the amount of pixels in its border. |
- | * fractalDimension: Returns the fractal dimension of a given polygon, which is calculated by the following equation: | + | * **fractalDimension**: Returns the fractal dimension of a given polygon, which is calculated by the following equation: |
{{ :interimage:fractal.png }} | {{ :interimage:fractal.png }} | ||
Where P is the polygon perimeter and A is the area. | Where P is the polygon perimeter and A is the area. | ||
- | * perimeterAreaRatio: Calculates the ratio between the perimeter and the area of a polygon. | + | * **perimeterAreaRatio**: Calculates the ratio between the perimeter and the area of a polygon. |
- | * compacity: Returns the compacity of a given polygon, which is calculated by the following equation: | + | * **compacity**: Returns the compacity of a given polygon, which is calculated by the following equation: |
{{ :interimage:compacity.png }} | {{ :interimage:compacity.png }} | ||
Where P is the polygon perimeter and A is the area. | Where P is the polygon perimeter and A is the area. | ||
- | * density: The density of a polygon is calculated by the ratio between its area and its Radius (the maximum distance between the polygon centroid and all its vertices). | + | * **density**: The density of a polygon is calculated by the ratio between its area and its Radius (the maximum distance between the polygon centroid and all its vertices). |
- | * length: The Length of a polygon is the height of its bounding box. | + | * **length**: The Length of a polygon is the height of its bounding box. |
- | * width: The Width of a polygon is calculated by the width of its bounding box. | + | * **width**: The Width of a polygon is calculated by the width of its bounding box. |
- | * contiguity: Contiguity index assesses the spatial connectedness of pixels within a polygon to provide an index of boundary configuration. | + | * **contiguity**: Contiguity index assesses the spatial connectedness of pixels within a polygon to provide an index of boundary configuration. |
- | * gyrationRadius: This attribute equals the mean distance between each pixel in the polygon and the polygon centroid. | + | * **gyrationRadius**: This attribute equals the mean distance between each pixel in the polygon and the polygon centroid. |
- | * angle: The main angle of a polygon. It is obtained by calculating the best elliptic fit, and the angle of the bigest radius of the ellipse corresponds to the polygon angle. | + | * **angle**: The main angle of a polygon. It is obtained by calculating the best elliptic fit, and the angle of the bigest radius of the ellipse corresponds to the polygon angle. |
- | * ellipticFit: Finds the best ellipse which fits outside the polygon and returns the ratio between the polygon area and the ellipse area. | + | * **ellipticFit**: Finds the best ellipse which fits outside the polygon and returns the ratio between the polygon area and the ellipse area. |
- | * squareness: This attribute fits the minimum rectangle outside the polygon and calculates the ratio between the polygon area and the area of this rectangle. The most close to 1 is this attribute, the most similar to a rectangle the polygon is. | + | * **squareness**: This attribute fits the minimum rectangle outside the polygon and calculates the ratio between the polygon area and the area of this rectangle. The most close to 1 is this attribute, the most similar to a rectangle the polygon is. |
- | * circleness: It is calculated by the following equation: | + | * **circleness**: It is calculated by the following equation: |
{{ :interimage:circle.png }} | {{ :interimage:circle.png }} | ||
Where A is the polygon area and R is the maximum distance between the polygon centroid and all its vertices. | Where A is the polygon area and R is the maximum distance between the polygon centroid and all its vertices. | ||
- | * shapeIndex: Returns the shape index of a given polygon, which is calculated by the following equation: | + | * **shapeIndex**: Returns the shape index of a given polygon, which is calculated by the following equation: |
{{ :interimage:shapeindex.png }} | {{ :interimage:shapeindex.png }} | ||
Where P is the polygon perimeter and A is the area. | Where P is the polygon perimeter and A is the area. | ||
+ | |||
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===== Spectral Statistical Attributes ===== | ===== Spectral Statistical Attributes ===== | ||
- | * **Amplitude** - | + | * **Amplitude** - represents the difference between the maximum and minimum pixel values of a region for the given image band/channel. |
* **Brightness** - | * **Brightness** - | ||
- | * **Correlation** - Correlation is a similarity measures between two data sets under an absolute scale between [-1,1]. It is calculated as showed by the next formula: | + | * **Correlation** - Correlation is a similarity measure between two data sets under an absolute scale between [-1,1]. It is calculated as showed by the next formula: |
{{ interimage:att_correlation.gif }} | {{ interimage:att_correlation.gif }} | ||
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* **Variance** - Like the standart deviation, the variance also represents the numerical data dispersion degree surrounding the mean but in the original data values scale. It is defined by: | * **Variance** - Like the standart deviation, the variance also represents the numerical data dispersion degree surrounding the mean but in the original data values scale. It is defined by: | ||
{{ interimage:att_variance.gif }} | {{ interimage:att_variance.gif }} | ||
+ | |||
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- | * **StdDeviationGLCM** - | + | * **StdDeviationGLCM** - The standart deviation is a measure that represents the values dispersion around a GLCM mean value. The GLCM standart deviation calcule differs from the simple standart deviation because the use of co-ocurrence frequencies. The calculus is showed by the next formula where "i" and "j" are adjacent image points values under one pre-defined direction. p(i,j) is the probability of that co-ocurrence over the image. |
+ | {{ interimage:att_stddeviationglcm.gif }} | ||
===== Neighborhood Attributes ===== | ===== Neighborhood Attributes ===== | ||
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* **meanDiffToNeighbors** - mean difference of the layer **L** mean value of an image object to the layer **L** mean value of direct neighbors (**R**=0) or all neighbor objects inside the range **R** (**R**>0). The differences are weighted with regard to the shared border (**R**=0) or the area covered by the neighbor objects inside the range (**R**>0). The distance between the image object and its neighbors is calculated considering their centroids. | * **meanDiffToNeighbors** - mean difference of the layer **L** mean value of an image object to the layer **L** mean value of direct neighbors (**R**=0) or all neighbor objects inside the range **R** (**R**>0). The differences are weighted with regard to the shared border (**R**=0) or the area covered by the neighbor objects inside the range (**R**>0). The distance between the image object and its neighbors is calculated considering their centroids. | ||
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