robocar-oak-camera/camera/text.py

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Python
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2022-08-10 10:28:41 +00:00
class HostSeqSync:
def __init__(self):
self.imfFrames = []
def add_msg(self, msg):
self.imfFrames.append(msg)
def get_msg(self, target_seq):
for i, imgFrame in enumerate(self.imfFrames):
if target_seq == imgFrame.getSequenceNum():
self.imfFrames = self.imfFrames[i:]
break
return self.imfFrames[0]
class CTCCodec(object):
""" Convert between text-label and text-index """
def __init__(self, characters):
# characters (str): set of the possible characters.
dict_character = list(characters)
self.dict = {}
for i, char in enumerate(dict_character):
self.dict[char] = i + 1
self.characters = dict_character
# print(self.characters)
# input()
def decode(self, preds):
""" convert text-index into text-label. """
texts = []
index = 0
# Select max probabilty (greedy decoding) then decode index to character
preds = preds.astype(np.float16)
preds_index = np.argmax(preds, 2)
preds_index = preds_index.transpose(1, 0)
preds_index_reshape = preds_index.reshape(-1)
preds_sizes = np.array([preds_index.shape[1]] * preds_index.shape[0])
for l in preds_sizes:
t = preds_index_reshape[index:index + l]
# NOTE: t might be zero size
if t.shape[0] == 0:
continue
char_list = []
for i in range(l):
# removing repeated characters and blank.
if not (i > 0 and t[i - 1] == t[i]):
if self.characters[t[i]] != '#':
char_list.append(self.characters[t[i]])
text = ''.join(char_list)
texts.append(text)
index += l
return texts