def process_parse(parse, device=None):
parse_ = []
for stk in parse:
# for ntraj = 1, set spline as the original stroke
if len(stk) == 1:
spl = torch.tensor(stk, dtype=torch.float, device=device)
parse_.append(spl)
continue
# for ntraj > 1, fit minimal spline to the stroke
stk = unif_space(stk)
stk = torch.tensor(stk, dtype=torch.float, device=device)
spl = fit_minimal_spline(stk, thresh=0.7, max_nland=50)
parse_.append(spl)
return parse_
def process_parse(parse, device=None, do_fit_spline=True):
""" same as gns.inference.parsing.top_k, but allowing to skip fitting
spline """
from pybpl.data import unif_space
from gns.omniglot.minimal_splines import fit_minimal_spline
parse_ = []
for stk in parse:
# for ntraj = 1, set spline as the original stroke
if len(stk) == 1:
spl = torch.tensor(stk, dtype=torch.float, device=device)
parse_.append(spl)
continue
# for ntraj > 1, fit minimal spline to the stroke
stk = unif_space(stk)
stk = torch.tensor(stk, dtype=torch.float, device=device)
if do_fit_spline:
spl = fit_minimal_spline(stk, thresh=0.7, max_nland=50)
else:
spl = stk
parse_.append(spl)
return parse_
def strokes2splines(strokes, npts_ver="unif_space", nland=7):
"""
Convert from strokes to splines, with the splines "rendered" back into
the spatial coords.
INPUTS
- strokes, list of np.arrays (N,2), where each is a stroke. could
also be (N,3) where 3rd col is time, this will be removed in splines.
- npts_ver, how to decide how many pts in splines to return
--- orig, keep origianl in input strokes
--- unif_space, use npts from unif space
- nland, number of control pts
RETURNS
- splines, list of np arrays, but diff num rows compared to inputs.
NOTE: throws out time dimension
"""
from pybpl.splines import fit_bspline_to_traj, get_stk_from_bspline
from pybpl.data import unif_space
# remove time dimenision
strokes = [s[:,:2] for s in strokes]
# keep track just in case
if npts_ver=="orig":
npts = [len(s) for s in strokes]
# strokes to tenorys
strokes = [torch.tensor(s) for s in strokes]
# make uniform in space
strokes = [unif_space(s) for s in strokes]
if npts_ver=="unif_space":
npts = [len(s) for s in strokes]
# get splines
if True:
splines = [fit_bspline_to_traj(s, nland=nland) for s in strokes]
else:
assert False, "not coded"
# Option 2
# if you don't know the right number of control points, use
# this function to determine the ncpts dynamically
# (available at gns.omniglot.minimal_splines)
# NOTE: make sure you have called unif_space()
def fit_minimal_spline(stroke, thresh=0.7, max_nland=100, normalize=True):
ntraj = stroke.size(0)
max_nland = min(max_nland, ntraj+1)
# determine num control points
for nland in range(1, max_nland):
spline, residuals = fit_bspline_to_traj(stroke, nland, include_resid=True)
loss = residuals.sum()
if normalize:
loss = loss / ntraj
if loss < thresh:
return spline
return spline
# upsample pts to match original
splines = [get_stk_from_bspline(spl, neval=n)
for spl, n in zip(splines, npts)]
# return to np arrays
splines = [s.numpy() for s in splines]
return splines
def stk_length(stk, uniform=False):
if uniform:
stk = unif_space(stk)
length = dist_along_traj(stk)
return length