def computeKatzLines(kSpace, anglesSorted, finiteAnglesSorted, K, centered = True, twoQuads = False):
'''
compute finite lines coordinates given Katz criterion
Returns a list or list of slice 2-tuples and corresponding list of angles and m values
perp computes the perpendicular (s) lines as well
'''
N, M = kSpace.shape
lines = []
angles = []
mValues = []
for m, angle in zip(finiteAnglesSorted, anglesSorted):
if isKatzCriterion(N, N, angles, K):
print("Katz Criterion Met. Breaking")
break
m, inv = farey.toFinite(angle, N)
u, v = radon.getSliceCoordinates2(m, kSpace, centered)
lines.append((u,v))
mValues.append(m)
angles.append(angle)
#second quadrant
if twoQuads:
if m != 0 and m != N: #dont repeat these
m = N-m
u, v = radon.getSliceCoordinates2(m, kSpace, centered)
lines.append((u,v))
mValues.append(m)
p, q = farey.get_pq(angle)
newAngle = farey.farey(-p,q) #not confirmed
angles.append(newAngle)
return lines, angles, mValues
def mojetteProjection(projection, N, angle, P, Q):
'''
Convert a finite projection into a Mojette projection for given (p,q).
Assumes you have correctly determined (p,q) for the m value of the finite projection.
'''
# dyadic = True
# if N % 2 == 1: # if odd, assume prime
# dyadic = False
p, q = farey.get_pq(angle)
B = farey.projectionLength(angle, P, Q) #no. of bins
m, inv = farey.toFinite(angle, N)
translateOffset, perp = farey.finiteTranslateOffset(angle, N, P, Q)
mojetteProj = np.zeros(B)
angleSign = p * q
'''if nt.is_coprime(q, N):
inv = q
else: #perp projection
inv = p
for translate, bin in enumerate(projection):
translateMojette = int((inv*translate)%N)
if angleSign >= 0 and perp: #Reverse for perp
translateMojette = int(translateOffset) - translateMojette
else:
translateMojette += int(translateOffset)
print "TR:", translate, "Tm:", translateMojette
mojetteProj[translateMojette] += bin'''
for translate, bin in enumerate(mojetteProj):
if angleSign >= 0 and perp: #Reverse for perp
translateMojette = int(translateOffset) - int(translate)
else:
translateMojette = int(translate) - int(translateOffset)
if translateMojette < 0:
translateFinite = (N - (inv * abs(translateMojette)) % N) % N
else:
translateFinite = (inv * translateMojette
) % N #has issues in C, may need checking
mojetteProj[translate] += projection[translateFinite]
# print "TR:", translateFinite, "TM:", translate
return mojetteProj
def computeLines(kSpace, angles, centered = True, twoQuads = False):
'''
compute finite lines coordinates
Returns a list or list of slice 2-tuples and corresponding list of m values
'''
p, s = kSpace.shape
lines = []
mValues = []
for angle in angles:
m, inv = farey.toFinite(angle, p)
u, v = radon.getSliceCoordinates2(m, kSpace, centered, p)
lines.append((u,v))
mValues.append(m)
#second quadrant
if twoQuads:
if m != 0 and m != p: #dont repeat these
m = p-m
u, v = radon.getSliceCoordinates2(m, kSpace, centered, p)
lines.append((u,v))
mValues.append(m)
return lines, mValues