Harris corner detector.
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| AFAPI features | harris (const array &in, const unsigned max_corners=500, const float min_response=1e5f, const float sigma=1.f, const unsigned block_size=0, const float k_thr=0.04f) |
| | C++ Interface for Harris corner detector. More...
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| AFAPI af_err | af_harris (af_features *out, const af_array in, const unsigned max_corners, const float min_response, const float sigma, const unsigned block_size, const float k_thr) |
| | C Interface for Harris corner detector. More...
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Harris corner detector.
Compute corners using the Harris corner detector approach. For each pixel, a small window is used to calculate the determinant and trace of such a window, from which a response is calculated. Pixels are considered corners if they are local maximas and have a high positive response.
| AFAPI af_err af_harris |
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af_features * |
out, |
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const af_array |
in, |
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const unsigned |
max_corners, |
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const float |
min_response, |
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const float |
sigma, |
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const unsigned |
block_size, |
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const float |
k_thr |
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) |
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C Interface for Harris corner detector.
- Parameters
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| [out] | out | struct containing arrays for x and y coordinates and score (Harris response), while arrays orientation and size are set to 0 and 1, respectively, because Harris does not compute that information |
| [in] | in | array containing a grayscale image (color images are not supported) |
| [in] | max_corners | maximum number of corners to keep, only retains those with highest Harris responses |
| [in] | min_response | minimum response in order for a corner to be retained, only used if max_corners = 0 |
| [in] | sigma | the standard deviation of a circular window (its dimensions will be calculated according to the standard deviation), the covariation matrix will be calculated to a circular neighborhood of this standard deviation (only used when block_size == 0, must be >= 0.5f and <= 5.0f) |
| [in] | block_size | square window size, the covariation matrix will be calculated to a square neighborhood of this size (must be >= 3 and <= 31) |
| [in] | k_thr | Harris constant, usually set empirically to 0.04f (must be >= 0.01f) |
| AFAPI features af::harris |
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const array & |
in, |
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const unsigned |
max_corners = 500, |
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const float |
min_response = 1e5f, |
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const float |
sigma = 1.f, |
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const unsigned |
block_size = 0, |
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const float |
k_thr = 0.04f |
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) |
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C++ Interface for Harris corner detector.
- Parameters
-
| [in] | in | array containing a grayscale image (color images are not supported) |
| [in] | max_corners | maximum number of corners to keep, only retains those with highest Harris responses |
| [in] | min_response | minimum response in order for a corner to be retained, only used if max_corners = 0 |
| [in] | sigma | the standard deviation of a circular window (its dimensions will be calculated according to the standard deviation), the covariation matrix will be calculated to a circular neighborhood of this standard deviation (only used when block_size == 0, must be >= 0.5f and <= 5.0f) |
| [in] | block_size | square window size, the covariation matrix will be calculated to a square neighborhood of this size (must be >= 3 and <= 31) |
| [in] | k_thr | Harris constant, usually set empirically to 0.04f (must be >= 0.01f) |
- Returns
- features object containing arrays for x and y coordinates and score (Harris response), while arrays orientation and size are set to 0 and 1, respectively, because Harris does not compute that information
