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Diffstat (limited to 'tests/python/test_line2d.py')
| -rw-r--r-- | tests/python/test_line2d.py | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/tests/python/test_line2d.py b/tests/python/test_line2d.py new file mode 100644 index 0000000..de68033 --- /dev/null +++ b/tests/python/test_line2d.py @@ -0,0 +1,310 @@ +import numpy as np +import unittest +import astra +import math +import pylab + +# return length of intersection of the line through points src = (x,y) +# and det (x,y), and the rectangle defined by xmin, ymin, xmax, ymax +# +# TODO: Generalize from 2D to n-dimensional +def intersect_line_rectangle(src, det, xmin, xmax, ymin, ymax): + EPS = 1e-5 + + if np.abs(src[0] - det[0]) < EPS: + if src[0] >= xmin and src[0] < xmax: + return ymax - ymin + else: + return 0.0 + if np.abs(src[1] - det[1]) < EPS: + if src[1] >= ymin and src[1] < ymax: + return xmax - xmin + else: + return 0.0 + + n = np.sqrt((det[0] - src[0]) ** 2 + (det[1] - src[1]) ** 2) + + check = [ (-(xmin - src[0]), -(det[0] - src[0]) / n ), + (xmax - src[0], (det[0] - src[0]) / n ), + (-(ymin - src[1]), -(det[1] - src[1]) / n ), + (ymax - src[1], (det[1] - src[1]) / n ) ] + + pre = [ -np.Inf ] + post = [ np.Inf ] + + for p, q in check: + r = p / (1.0 * q) + if q > 0: + post.append(r) # exiting half-plane + else: + pre.append(r) # entering half-plane + + end_r = np.min(post) + start_r = np.max(pre) + + if end_r > start_r: + return end_r - start_r + else: + return 0.0 + +def intersect_line_rectangle_feather(src, det, xmin, xmax, ymin, ymax, feather): + return intersect_line_rectangle(src, det, + xmin-feather, xmax+feather, + ymin-feather, ymax+feather) + +def intersect_line_rectangle_interval(src, det, xmin, xmax, ymin, ymax, f): + a = intersect_line_rectangle_feather(src, det, xmin, xmax, ymin, ymax, -f) + b = intersect_line_rectangle(src, det, xmin, xmax, ymin, ymax) + c = intersect_line_rectangle_feather(src, det, xmin, xmax, ymin, ymax, f) + return (a,b,c) + +def gen_lines_fanflat(proj_geom): + angles = proj_geom['ProjectionAngles'] + for theta in angles: + #theta = -theta + src = ( math.sin(theta) * proj_geom['DistanceOriginSource'], + -math.cos(theta) * proj_geom['DistanceOriginSource'] ) + detc= (-math.sin(theta) * proj_geom['DistanceOriginDetector'], + math.cos(theta) * proj_geom['DistanceOriginDetector'] ) + detu= ( math.cos(theta) * proj_geom['DetectorWidth'], + math.sin(theta) * proj_geom['DetectorWidth'] ) + + src = np.array(src, dtype=np.float64) + detc= np.array(detc, dtype=np.float64) + detu= np.array(detu, dtype=np.float64) + + detb= detc + (0.5 - 0.5*proj_geom['DetectorCount']) * detu + + for i in range(proj_geom['DetectorCount']): + yield (src, detb + i * detu) + +def gen_lines_fanflat_vec(proj_geom): + v = proj_geom['Vectors'] + for i in range(v.shape[0]): + src = v[i,0:2] + detc = v[i,2:4] + detu = v[i,4:6] + + detb = detc + (0.5 - 0.5*proj_geom['DetectorCount']) * detu + for i in range(proj_geom['DetectorCount']): + yield (src, detb + i * detu) + +def gen_lines_parallel(proj_geom): + angles = proj_geom['ProjectionAngles'] + for theta in angles: + ray = ( math.sin(theta), + -math.cos(theta) ) + detc= (0, 0 ) + detu= ( math.cos(theta) * proj_geom['DetectorWidth'], + math.sin(theta) * proj_geom['DetectorWidth'] ) + + ray = np.array(ray, dtype=np.float64) + detc= np.array(detc, dtype=np.float64) + detu= np.array(detu, dtype=np.float64) + + + detb= detc + (0.5 - 0.5*proj_geom['DetectorCount']) * detu + + for i in range(proj_geom['DetectorCount']): + yield (detb + i * detu - ray, detb + i * detu) + +def gen_lines_parallel_vec(proj_geom): + v = proj_geom['Vectors'] + for i in range(v.shape[0]): + ray = v[i,0:2] + detc = v[i,2:4] + detu = v[i,4:6] + + detb = detc + (0.5 - 0.5*proj_geom['DetectorCount']) * detu + + for i in range(proj_geom['DetectorCount']): + yield (detb + i * detu - ray, detb + i * detu) + + +def gen_lines(proj_geom): + g = { 'fanflat': gen_lines_fanflat, + 'fanflat_vec': gen_lines_fanflat_vec, + 'parallel': gen_lines_parallel, + 'parallel_vec': gen_lines_parallel_vec } + for l in g[proj_geom['type']](proj_geom): + yield l + +range2d = ( 8, 64 ) + + +def gen_random_geometry_fanflat(): + pg = astra.create_proj_geom('fanflat', 0.6 + 0.8 * np.random.random(), np.random.randint(*range2d), np.linspace(0, 2*np.pi, np.random.randint(*range2d), endpoint=False), 256 * (0.5 + np.random.random()), 256 * np.random.random()) + return pg + +def gen_random_geometry_parallel(): + pg = astra.create_proj_geom('parallel', 0.8 + 0.4 * np.random.random(), np.random.randint(*range2d), np.linspace(0, 2*np.pi, np.random.randint(*range2d), endpoint=False)) + return pg + +def gen_random_geometry_fanflat_vec(): + Vectors = np.zeros([16,6]) + # We assume constant detector width in these tests + w = 0.6 + 0.8 * np.random.random() + for i in range(Vectors.shape[0]): + angle1 = 2*np.pi*np.random.random() + angle2 = angle1 + 0.5 * np.random.random() + dist1 = 256 * (0.5 + np.random.random()) + detc = 10 * np.random.random(size=2) + detu = [ math.cos(angle1) * w, math.sin(angle1) * w ] + src = [ math.sin(angle2) * dist1, -math.cos(angle2) * dist1 ] + Vectors[i, :] = [ src[0], src[1], detc[0], detc[1], detu[0], detu[1] ] + pg = astra.create_proj_geom('fanflat_vec', np.random.randint(*range2d), Vectors) + + # TODO: Randomize more + pg = astra.create_proj_geom('fanflat_vec', np.random.randint(*range2d), Vectors) + return pg + +def gen_random_geometry_parallel_vec(): + Vectors = np.zeros([16,6]) + # We assume constant detector width in these tests + w = 0.6 + 0.8 * np.random.random() + for i in range(Vectors.shape[0]): + l = 0.6 + 0.8 * np.random.random() + angle1 = 2*np.pi*np.random.random() + angle2 = angle1 + 0.5 * np.random.random() + detc = 10 * np.random.random(size=2) + detu = [ math.cos(angle1) * w, math.sin(angle1) * w ] + ray = [ math.sin(angle2) * l, -math.cos(angle2) * l ] + Vectors[i, :] = [ ray[0], ray[1], detc[0], detc[1], detu[0], detu[1] ] + pg = astra.create_proj_geom('parallel_vec', np.random.randint(*range2d), Vectors) + return pg + + + + +nloops = 50 +seed = 123 + +class TestLineKernel(unittest.TestCase): + def single_test(self, type): + shape = np.random.randint(*range2d, size=2) + # these rectangles are biased, but that shouldn't matter + rect_min = [ np.random.randint(0, a) for a in shape ] + rect_max = [ np.random.randint(rect_min[i]+1, shape[i]+1) for i in range(len(shape))] + if True: + #pixsize = 0.5 + np.random.random(size=2) + pixsize = np.array([0.5, 0.5]) + np.random.random() + origin = 10 * np.random.random(size=2) + else: + pixsize = (1.,1.) + origin = (0.,0.) + vg = astra.create_vol_geom(shape[1], shape[0], + origin[0] - 0.5 * shape[0] * pixsize[0], + origin[0] + 0.5 * shape[0] * pixsize[0], + origin[1] - 0.5 * shape[1] * pixsize[1], + origin[1] + 0.5 * shape[1] * pixsize[1]) + #print(vg) + + if type == 'parallel': + pg = gen_random_geometry_parallel() + projector_id = astra.create_projector('line', pg, vg) + elif type == 'parallel_vec': + pg = gen_random_geometry_parallel_vec() + projector_id = astra.create_projector('line', pg, vg) + elif type == 'fanflat': + pg = gen_random_geometry_fanflat() + projector_id = astra.create_projector('line_fanflat', pg, vg) + elif type == 'fanflat_vec': + pg = gen_random_geometry_fanflat_vec() + projector_id = astra.create_projector('line_fanflat', pg, vg) + + + data = np.zeros((shape[1], shape[0]), dtype=np.float32) + data[rect_min[1]:rect_max[1],rect_min[0]:rect_max[0]] = 1 + + sinogram_id, sinogram = astra.create_sino(data, projector_id) + + #print(pg) + #print(vg) + + astra.data2d.delete(sinogram_id) + + astra.projector.delete(projector_id) + + a = np.zeros(np.prod(astra.functions.geom_size(pg)), dtype=np.float32) + b = np.zeros(np.prod(astra.functions.geom_size(pg)), dtype=np.float32) + c = np.zeros(np.prod(astra.functions.geom_size(pg)), dtype=np.float32) + + i = 0 + #print( origin[0] + (-0.5 * shape[0] + rect_min[0]) * pixsize[0], origin[0] + (-0.5 * shape[0] + rect_max[0]) * pixsize[0], origin[1] + (-0.5 * shape[1] + rect_min[1]) * pixsize[1], origin[1] + (-0.5 * shape[1] + rect_max[1]) * pixsize[1]) + for src, det in gen_lines(pg): + #print(src,det) + + # NB: Flipped y-axis here, since that is how astra interprets 2D volumes + # We compute line intersections with slightly bigger (cw) and + # smaller (aw) rectangles, and see if the kernel falls + # between these two values. + (aw,bw,cw) = intersect_line_rectangle_interval(src, det, + origin[0] + (-0.5 * shape[0] + rect_min[0]) * pixsize[0], + origin[0] + (-0.5 * shape[0] + rect_max[0]) * pixsize[0], + origin[1] + (+0.5 * shape[1] - rect_max[1]) * pixsize[1], + origin[1] + (+0.5 * shape[1] - rect_min[1]) * pixsize[1], + 1e-3) + a[i] = aw + b[i] = bw + c[i] = cw + i += 1 + # Add weight for pixel / voxel size + try: + detweight = pg['DetectorWidth'] + except KeyError: + detweight = np.sqrt(pg['Vectors'][0,4]*pg['Vectors'][0,4] + pg['Vectors'][0,5]*pg['Vectors'][0,5] ) + a *= detweight + b *= detweight + c *= detweight + a = a.reshape(astra.functions.geom_size(pg)) + b = b.reshape(astra.functions.geom_size(pg)) + c = c.reshape(astra.functions.geom_size(pg)) + + # Check if sinogram lies between a and c + y = np.min(sinogram-a) + z = np.min(c-sinogram) + x = np.max(np.abs(sinogram-b)) # ideally this is small, but can be large + # due to discontinuities in line kernel + self.assertFalse(z < 0 or y < 0) + if z < 0 or y < 0: + print(y,z,x) + pylab.gray() + pylab.imshow(data) + pylab.figure() + pylab.imshow(sinogram) + pylab.figure() + pylab.imshow(b) + pylab.figure() + pylab.imshow(a) + pylab.figure() + pylab.imshow(c) + pylab.figure() + pylab.imshow(sinogram-a) + pylab.figure() + pylab.imshow(c-sinogram) + pylab.show() + + def test_par(self): + np.random.seed(seed) + for _ in range(nloops): + self.single_test('parallel') + def test_fan(self): + np.random.seed(seed) + for _ in range(nloops): + self.single_test('fanflat') + def test_parvec(self): + np.random.seed(seed) + for _ in range(nloops): + self.single_test('parallel_vec') + def test_fanvec(self): + np.random.seed(seed) + for _ in range(nloops): + self.single_test('fanflat_vec') + + + + +if __name__ == '__main__': + unittest.main() + +#print(intersect_line_rectangle((0.,-256.),(-27.,0.),11.6368454385 20.173128227 3.18989047649 5.62882841606) |