in easycv/datasets/ocr/pipelines/rec_transform.py [0:0]
def calc_delta(self):
w = np.zeros(self.pt_count, dtype=np.float32)
if self.pt_count < 2:
return
i = 0
while 1:
if self.dst_w <= i < self.dst_w + self.grid_size - 1:
i = self.dst_w - 1
elif i >= self.dst_w:
break
j = 0
while 1:
if self.dst_h <= j < self.dst_h + self.grid_size - 1:
j = self.dst_h - 1
elif j >= self.dst_h:
break
sw = 0
swp = np.zeros(2, dtype=np.float32)
swq = np.zeros(2, dtype=np.float32)
new_pt = np.zeros(2, dtype=np.float32)
cur_pt = np.array([i, j], dtype=np.float32)
k = 0
for k in range(self.pt_count):
if i == self.dst_pts[k][0] and j == self.dst_pts[k][1]:
break
w[k] = 1. / ((i - self.dst_pts[k][0]) *
(i - self.dst_pts[k][0]) +
(j - self.dst_pts[k][1]) *
(j - self.dst_pts[k][1]))
sw += w[k]
swp = swp + w[k] * np.array(self.dst_pts[k])
swq = swq + w[k] * np.array(self.src_pts[k])
if k == self.pt_count - 1:
pstar = 1 / sw * swp
qstar = 1 / sw * swq
miu_s = 0
for k in range(self.pt_count):
if i == self.dst_pts[k][0] and j == self.dst_pts[k][1]:
continue
pt_i = self.dst_pts[k] - pstar
miu_s += w[k] * np.sum(pt_i * pt_i)
cur_pt -= pstar
cur_pt_j = np.array([-cur_pt[1], cur_pt[0]])
for k in range(self.pt_count):
if i == self.dst_pts[k][0] and j == self.dst_pts[k][1]:
continue
pt_i = self.dst_pts[k] - pstar
pt_j = np.array([-pt_i[1], pt_i[0]])
tmp_pt = np.zeros(2, dtype=np.float32)
tmp_pt[0] = np.sum(
pt_i * cur_pt) * self.src_pts[k][0] - np.sum(
pt_j * cur_pt) * self.src_pts[k][1]
tmp_pt[1] = -np.sum(pt_i * cur_pt_j) * self.src_pts[k][
0] + np.sum(pt_j * cur_pt_j) * self.src_pts[k][1]
tmp_pt *= (w[k] / miu_s)
new_pt += tmp_pt
new_pt += qstar
else:
new_pt = self.src_pts[k]
self.rdx[j, i] = new_pt[0] - i
self.rdy[j, i] = new_pt[1] - j
j += self.grid_size
i += self.grid_size