peri/initializers.py
def harris_feature(im, region_size=5, to_return='harris', scale=0.05):
    """
    Harris-motivated feature detection on a d-dimensional image.

    Parameters
    ---------
        im
        region_size
        to_return : {'harris','matrix','trace-determinant'}

    """
    ndim = im.ndim
    #1. Gradient of image
    grads = [nd.sobel(im, axis=i) for i in range(ndim)]
    #2. Corner response matrix
    matrix = np.zeros((ndim, ndim) + im.shape)
    for a in range(ndim):
        for b in range(ndim):
            matrix[a,b] = nd.filters.gaussian_filter(grads[a]*grads[b],
                    region_size)
    if to_return == 'matrix':
        return matrix
    #3. Trace, determinant
    trc = np.trace(matrix, axis1=0, axis2=1)
    det = np.linalg.det(matrix.T).T
    if to_return == 'trace-determinant':
        return trc, det
    else:
        #4. Harris detector:
        harris = det - scale*trc*trc
        return harris
def harris_feature(im, region_size=5, to_return='harris', scale=0.05):
    """
    Harris-motivated feature detection on a d-dimensional image.

    Parameters
    ---------
        im
        region_size
        to_return : {'harris','matrix','trace-determinant'}

    """
    ndim = im.ndim
    #1. Gradient of image
    grads = [nd.sobel(im, axis=i) for i in range(ndim)]
    #2. Corner response matrix
    matrix = np.zeros((ndim, ndim) + im.shape)
    for a in range(ndim):
        for b in range(ndim):
            matrix[a,b] = nd.filters.gaussian_filter(grads[a]*grads[b],
                    region_size)
    if to_return == 'matrix':
        return matrix
    #3. Trace, determinant
    trc = np.trace(matrix, axis1=0, axis2=1)
    det = np.linalg.det(matrix.T).T
    if to_return == 'trace-determinant':
        return trc, det
    else:
        #4. Harris detector:
        harris = det - scale*trc*trc
        return harris
def harris_feature ( im , region_size = 5 , to_return = 'harris' , scale = 0.05 ) : ndim = im . ndim #1. Gradient of image grads = [ nd . sobel ( im , axis = i ) for i in range ( ndim ) ] #2. Corner response matrix matrix = np . zeros ( ( ndim , ndim ) + im . shape ) for a in range ( ndim ) : for b in range ( ndim ) : matrix [ a , b ] = nd . filters . gaussian_filter ( grads [ a ] * grads [ b ] , region_size ) if to_return == 'matrix' : return matrix #3. Trace, determinant trc = np . trace ( matrix , axis1 = 0 , axis2 = 1 ) det = np . linalg . det ( matrix . T ) . T if to_return == 'trace-determinant' : return trc , det else : #4. Harris detector: harris = det - scale * trc * trc return harris
Harris-motivated feature detection on a d-dimensional image.

    Parameters
    ---------
        im
        region_size
        to_return : {'harris','matrix','trace-determinant'}
Harris - motivated feature detection on a d - dimensional image .