diff --git a/skimage/feature/censure.py b/skimage/feature/censure.py index c6ab7f38..7f2ae816 100644 --- a/skimage/feature/censure.py +++ b/skimage/feature/censure.py @@ -1,17 +1,18 @@ import numpy as np -from scipy.ndimage.filters import maximum_filter, minimum_filter +from scipy.ndimage.filters import maximum_filter, minimum_filter, convolve from ..transform import integral_image from ..feature.corner import _compute_auto_correlation from ..util import img_as_float +from ..morphology import convex_hull_image from .censure_cy import _censure_dob_loop, _slanted_integral_image, _censure_octagon_loop def _get_filtered_image(image, n_scales, mode): # TODO : Implement the STAR mode + scales = np.zeros((image.shape[0], image.shape[1], n_scales), dtype=np.double) if mode == 'DoB': - scales = np.zeros((image.shape[0], image.shape[1], n_scales)) for i in range(n_scales): n = i + 1 # Constant multipliers for the outer region and the inner region @@ -23,13 +24,15 @@ def _get_filtered_image(image, n_scales, mode): filtered_image = np.zeros(image.shape) _censure_dob_loop(image, n, integral_img, filtered_image, inner_weight, outer_weight) scales[:, :, i] = filtered_image - return scales + elif mode == 'Octagon': # TODO : Decide the shapes of Octagon filters for scales > 7 outer_shape = [(5, 2), (5, 3), (7, 3), (9, 4), (9, 7), (13, 7), (15, 10)] inner_shape = [(3, 0), (3, 1), (3, 2), (5, 2), (5, 3), (5, 4), (5, 5)] - scales = np.zeros((image.shape[0], image.shape[1], n_scales)) + for i in range(n_scales): + scales[:, :, i] = convolve(image, _octagon_filter(outer_shape[i][0], outer_shape[i][1], inner_shape[i][0], inner_shape[i][1])) + """ integral_img = integral_image(image) integral_img1 = _slanted_integral_image_modes(image, 1) integral_img2 = _slanted_integral_image_modes(image, 2) @@ -51,7 +54,50 @@ def _get_filtered_image(image, n_scales, mode): _censure_octagon_loop(image, integral_img, integral_img1, integral_img2, integral_img3, integral_img4, filtered_image, outer_weight, inner_weight, mo, no, mi, ni) scales[:, :, k] = filtered_image - return scales + """ + return scales + + +def _oct(m, n): + f = np.zeros((m + 2*n, m + 2*n)) + f[0, n] = 1 + f[n, 0] = 1 + f[0, m + n -1] = 1 + f[m + n - 1, 0] = 1 + f[-1, n] = 1 + f[n, -1] = 1 + f[-1, m + n - 1] = 1 + f[m + n - 1, -1] = 1 + return convex_hull_image(f).astype(int) + + +def _octagon_filter(mo, no, mi, ni): + outer = (mo + 2 * no)**2 - 2 * no * (no + 1) + inner = (mi + 2 * ni)**2 - 2 * ni * (ni + 1) + outer_wt = 1.0 / (outer - inner) + inner_wt = 1.0 / inner + c = ((mo + 2 * no) - (mi + 2 * ni)) / 2 + outer_oct = _oct(mo, no) + inner_oct = np.zeros((mo + 2 * no, mo + 2 * no)) + inner_oct[c:-c, c:-c] = _oct(mi, ni) + bfilter = outer_wt * outer_oct - (outer_wt + inner_wt) * inner_oct + return bfilter + + +def _filter_using_convolve(image, n, mode='DoB'): + + if mode == 'DoB': + inner_wt = (1.0 / (2*n + 1)**2) + outer_wt = (1.0 / (12*n**2 + 4*n)) + dob_filter = np.zeros((4 * n + 1, 4 * n + 1)) + dob_filter[:] = outer_wt + dob_filter[n : 3 * n + 1, n : 3 * n + 1] = - inner_wt + return convolve(image, dob_filter) + + elif mode == 'Octagon': + outer_shape = [(5, 2), (5, 3), (7, 3), (9, 4), (9, 7), (13, 7), (15, 10)] + inner_shape = [(3, 0), (3, 1), (3, 2), (5, 2), (5, 3), (5, 4), (5, 5)] + return convolve(image, _octagon_filter(outer_shape[n - 1][0], outer_shape[n - 1][1], inner_shape[n - 1][0], inner_shape[n - 1][1])) def _slanted_integral_image_modes(img, mode=1):