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interimage:attributes_description [2010/06/23 17:32] hermann |
interimage:attributes_description [2012/07/12 18:27] rsilva |
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| * **yGeoCenter** - y geo-coordinate of the object centroid. | * **yGeoCenter** - y geo-coordinate of the object centroid. | ||
| * **membership** or **p** - confidence in the object with regard to its classification. | * **membership** or **p** - confidence in the object with regard to its classification. | ||
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| ===== Shape Attributes ===== | ===== Shape Attributes ===== | ||
| - | * **area**: Returns the area of the given polygon, in number of pixels. | + | * **area** - Returns the real area of the given polygon. |
| - | * **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 biggest 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 biggest 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 t closest 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 t closest 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** - represents the difference between the maximum and minimum pixel values of a region for the given image band/channel. | + | * **Amplitude** - represents the difference between the maximum and minimum pixel values of an object for the given image layer **L**. |
| - | * **Brightness** - | + | * **Brightness** - represents the brightness of an image object. |
| * **Correlation** - Correlation is a similarity measure between two data sets under an absolute scale between [-1,1]. It is calculated as shown 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 shown by the next formula: | ||
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| - | * **Ratio** - | + | * **Ratio** - represents the amount that layer **L** contributes to the total brightness of an image object. |
| * **StdDeviation** - The standard deviation represents the numerical data dispersion degree surrounding the mean. It is defined by: | * **StdDeviation** - The standard deviation represents the numerical data dispersion degree surrounding the mean. It is defined by: | ||
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| * **SumPixelsValues** - Represents the sum of all element values inside an area for one given image band/channel. | * **SumPixelsValues** - Represents the sum of all element values inside an area for one given image band/channel. | ||
| - | a * **Variance** - Like the standard deviation, the variance also represents the numerical data dispersion degree surrounding the mean but in the original data value scale. It is defined by: | + | * **Variance** - Like the standard deviation, the variance also represents the numerical data dispersion degree surrounding the mean but in the original data value scale. It is defined by: |
| {{ interimage:att_variance.gif }} | {{ interimage:att_variance.gif }} | ||
