rec_postprocess.py

# copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import numpy as np
import paddle
from paddle.nn import functional as F
import re


class BaseRecLabelDecode(object):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False):
        self.beg_str = "sos"
        self.end_str = "eos"
        self.reverse = False
        self.character_str = []

        if character_dict_path is None:
            self.character_str = "0123456789abcdefghijklmnopqrstuvwxyz"
            dict_character = list(self.character_str)
        else:
            with open(character_dict_path, "rb") as fin:
                lines = fin.readlines()
                for line in lines:
                    line = line.decode("utf-8").strip("\n").strip("\r\n")
                    self.character_str.append(line)
            if use_space_char:
                self.character_str.append(" ")
            dict_character = list(self.character_str)
            if "arabic" in character_dict_path:
                self.reverse = True

        dict_character = self.add_special_char(dict_character)
        self.dict = {}
        for i, char in enumerate(dict_character):
            self.dict[char] = i
        self.character = dict_character

    def pred_reverse(self, pred):
        pred_re = []
        c_current = ""
        for c in pred:
            if not bool(re.search("[a-zA-Z0-9 :*./%+-]", c)):
                if c_current != "":
                    pred_re.append(c_current)
                pred_re.append(c)
                c_current = ""
            else:
                c_current += c
        if c_current != "":
            pred_re.append(c_current)

        return "".join(pred_re[::-1])

    def add_special_char(self, dict_character):
        return dict_character

    def get_word_info(self, text, selection):
        """
        Group the decoded characters and record the corresponding decoded positions.

        Args:
            text: the decoded text
            selection: the bool array that identifies which columns of features are decoded as non-separated characters
        Returns:
            word_list: list of the grouped words
            word_col_list: list of decoding positions corresponding to each character in the grouped word
            state_list: list of marker to identify the type of grouping words, including two types of grouping words:
                        - 'cn': continous chinese characters (e.g., 你好啊)
                        - 'en&num': continous english characters (e.g., hello), number (e.g., 123, 1.123), or mixed of them connected by '-' (e.g., VGG-16)
                        The remaining characters in text are treated as separators between groups (e.g., space, '(', ')', etc.).
        """
        state = None
        word_content = []
        word_col_content = []
        word_list = []
        word_col_list = []
        state_list = []
        valid_col = np.where(selection == True)[0]

        for c_i, char in enumerate(text):
            if "\u4e00" <= char <= "\u9fff":
                c_state = "cn"
            elif bool(re.search("[a-zA-Z0-9]", char)):
                c_state = "en&num"
            else:
                c_state = "splitter"

            if (
                char == "."
                and state == "en&num"
                and c_i + 1 < len(text)
                and bool(re.search("[0-9]", text[c_i + 1]))
            ):  # grouping floting number
                c_state = "en&num"
            if (
                char == "-" and state == "en&num"
            ):  # grouping word with '-', such as 'state-of-the-art'
                c_state = "en&num"

            if state == None:
                state = c_state

            if state != c_state:
                if len(word_content) != 0:
                    word_list.append(word_content)
                    word_col_list.append(word_col_content)
                    state_list.append(state)
                    word_content = []
                    word_col_content = []
                state = c_state

            if state != "splitter":
                word_content.append(char)
                word_col_content.append(valid_col[c_i])

        if len(word_content) != 0:
            word_list.append(word_content)
            word_col_list.append(word_col_content)
            state_list.append(state)

        return word_list, word_col_list, state_list

    def decode(
        self,
        text_index,
        text_prob=None,
        is_remove_duplicate=False,
        return_word_box=False,
    ):
        """convert text-index into text-label."""
        result_list = []
        ignored_tokens = self.get_ignored_tokens()
        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            selection = np.ones(len(text_index[batch_idx]), dtype=bool)
            if is_remove_duplicate:
                selection[1:] = text_index[batch_idx][1:] != text_index[batch_idx][:-1]
            for ignored_token in ignored_tokens:
                selection &= text_index[batch_idx] != ignored_token

            char_list = [
                self.character[text_id] for text_id in text_index[batch_idx][selection]
            ]
            if text_prob is not None:
                conf_list = text_prob[batch_idx][selection]
            else:
                conf_list = [1] * len(selection)
            if len(conf_list) == 0:
                conf_list = [0]

            text = "".join(char_list)

            if self.reverse:  # for arabic rec
                text = self.pred_reverse(text)

            if return_word_box:
                word_list, word_col_list, state_list = self.get_word_info(
                    text, selection
                )
                result_list.append(
                    (
                        text,
                        np.mean(conf_list).tolist(),
                        [
                            len(text_index[batch_idx]),
                            word_list,
                            word_col_list,
                            state_list,
                        ],
                    )
                )
            else:
                result_list.append((text, np.mean(conf_list).tolist()))
        return result_list

    def get_ignored_tokens(self):
        return [0]  # for ctc blank


class CTCLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(CTCLabelDecode, self).__init__(character_dict_path, use_space_char)

    def __call__(self, preds, label=None, return_word_box=False, *args, **kwargs):
        if isinstance(preds, tuple) or isinstance(preds, list):
            preds = preds[-1]
        if isinstance(preds, paddle.Tensor):
            preds = preds.numpy()
        preds_idx = preds.argmax(axis=2)
        preds_prob = preds.max(axis=2)
        text = self.decode(
            preds_idx,
            preds_prob,
            is_remove_duplicate=True,
            return_word_box=return_word_box,
        )
        if return_word_box:
            for rec_idx, rec in enumerate(text):
                wh_ratio = kwargs["wh_ratio_list"][rec_idx]
                max_wh_ratio = kwargs["max_wh_ratio"]
                rec[2][0] = rec[2][0] * (wh_ratio / max_wh_ratio)
        if label is None:
            return text
        label = self.decode(label)
        return text, label

    def add_special_char(self, dict_character):
        dict_character = ["blank"] + dict_character
        return dict_character


class DistillationCTCLabelDecode(CTCLabelDecode):
    """
    Convert
    Convert between text-label and text-index
    """

    def __init__(
        self,
        character_dict_path=None,
        use_space_char=False,
        model_name=["student"],
        key=None,
        multi_head=False,
        **kwargs,
    ):
        super(DistillationCTCLabelDecode, self).__init__(
            character_dict_path, use_space_char
        )
        if not isinstance(model_name, list):
            model_name = [model_name]
        self.model_name = model_name

        self.key = key
        self.multi_head = multi_head

    def __call__(self, preds, label=None, *args, **kwargs):
        output = dict()
        for name in self.model_name:
            pred = preds[name]
            if self.key is not None:
                pred = pred[self.key]
            if self.multi_head and isinstance(pred, dict):
                pred = pred["ctc"]
            output[name] = super().__call__(pred, label=label, *args, **kwargs)
        return output


class AttnLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(AttnLabelDecode, self).__init__(character_dict_path, use_space_char)

    def add_special_char(self, dict_character):
        self.beg_str = "sos"
        self.end_str = "eos"
        dict_character = dict_character
        dict_character = [self.beg_str] + dict_character + [self.end_str]
        return dict_character

    def decode(self, text_index, text_prob=None, is_remove_duplicate=False):
        """convert text-index into text-label."""
        result_list = []
        ignored_tokens = self.get_ignored_tokens()
        [beg_idx, end_idx] = self.get_ignored_tokens()
        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []
            for idx in range(len(text_index[batch_idx])):
                if text_index[batch_idx][idx] in ignored_tokens:
                    continue
                if int(text_index[batch_idx][idx]) == int(end_idx):
                    break
                if is_remove_duplicate:
                    # only for predict
                    if (
                        idx > 0
                        and text_index[batch_idx][idx - 1] == text_index[batch_idx][idx]
                    ):
                        continue
                char_list.append(self.character[int(text_index[batch_idx][idx])])
                if text_prob is not None:
                    conf_list.append(text_prob[batch_idx][idx])
                else:
                    conf_list.append(1)
            text = "".join(char_list)
            result_list.append((text, np.mean(conf_list).tolist()))
        return result_list

    def __call__(self, preds, label=None, *args, **kwargs):
        """
        text = self.decode(text)
        if label is None:
            return text
        else:
            label = self.decode(label, is_remove_duplicate=False)
            return text, label
        """
        if isinstance(preds, paddle.Tensor):
            preds = preds.numpy()

        preds_idx = preds.argmax(axis=2)
        preds_prob = preds.max(axis=2)
        text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)
        if label is None:
            return text
        label = self.decode(label, is_remove_duplicate=False)
        return text, label

    def get_ignored_tokens(self):
        beg_idx = self.get_beg_end_flag_idx("beg")
        end_idx = self.get_beg_end_flag_idx("end")
        return [beg_idx, end_idx]

    def get_beg_end_flag_idx(self, beg_or_end):
        if beg_or_end == "beg":
            idx = np.array(self.dict[self.beg_str])
        elif beg_or_end == "end":
            idx = np.array(self.dict[self.end_str])
        else:
            assert False, "unsupport type %s in get_beg_end_flag_idx" % beg_or_end
        return idx


class RFLLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(RFLLabelDecode, self).__init__(character_dict_path, use_space_char)

    def add_special_char(self, dict_character):
        self.beg_str = "sos"
        self.end_str = "eos"
        dict_character = dict_character
        dict_character = [self.beg_str] + dict_character + [self.end_str]
        return dict_character

    def decode(self, text_index, text_prob=None, is_remove_duplicate=False):
        """convert text-index into text-label."""
        result_list = []
        ignored_tokens = self.get_ignored_tokens()
        [beg_idx, end_idx] = self.get_ignored_tokens()
        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []
            for idx in range(len(text_index[batch_idx])):
                if text_index[batch_idx][idx] in ignored_tokens:
                    continue
                if int(text_index[batch_idx][idx]) == int(end_idx):
                    break
                if is_remove_duplicate:
                    # only for predict
                    if (
                        idx > 0
                        and text_index[batch_idx][idx - 1] == text_index[batch_idx][idx]
                    ):
                        continue
                char_list.append(self.character[int(text_index[batch_idx][idx])])
                if text_prob is not None:
                    conf_list.append(text_prob[batch_idx][idx])
                else:
                    conf_list.append(1)
            text = "".join(char_list)
            result_list.append((text, np.mean(conf_list).tolist()))
        return result_list

    def __call__(self, preds, label=None, *args, **kwargs):
        # if seq_outputs is not None:
        if isinstance(preds, tuple) or isinstance(preds, list):
            cnt_outputs, seq_outputs = preds
            if isinstance(seq_outputs, paddle.Tensor):
                seq_outputs = seq_outputs.numpy()
            preds_idx = seq_outputs.argmax(axis=2)
            preds_prob = seq_outputs.max(axis=2)
            text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)

            if label is None:
                return text
            label = self.decode(label, is_remove_duplicate=False)
            return text, label

        else:
            cnt_outputs = preds
            if isinstance(cnt_outputs, paddle.Tensor):
                cnt_outputs = cnt_outputs.numpy()
            cnt_length = []
            for lens in cnt_outputs:
                length = round(np.sum(lens))
                cnt_length.append(length)
            if label is None:
                return cnt_length
            label = self.decode(label, is_remove_duplicate=False)
            length = [len(res[0]) for res in label]
            return cnt_length, length

    def get_ignored_tokens(self):
        beg_idx = self.get_beg_end_flag_idx("beg")
        end_idx = self.get_beg_end_flag_idx("end")
        return [beg_idx, end_idx]

    def get_beg_end_flag_idx(self, beg_or_end):
        if beg_or_end == "beg":
            idx = np.array(self.dict[self.beg_str])
        elif beg_or_end == "end":
            idx = np.array(self.dict[self.end_str])
        else:
            assert False, "unsupport type %s in get_beg_end_flag_idx" % beg_or_end
        return idx


class SEEDLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(SEEDLabelDecode, self).__init__(character_dict_path, use_space_char)

    def add_special_char(self, dict_character):
        self.padding_str = "padding"
        self.end_str = "eos"
        self.unknown = "unknown"
        dict_character = dict_character + [self.end_str, self.padding_str, self.unknown]
        return dict_character

    def get_ignored_tokens(self):
        end_idx = self.get_beg_end_flag_idx("eos")
        return [end_idx]

    def get_beg_end_flag_idx(self, beg_or_end):
        if beg_or_end == "sos":
            idx = np.array(self.dict[self.beg_str])
        elif beg_or_end == "eos":
            idx = np.array(self.dict[self.end_str])
        else:
            assert False, "unsupport type %s in get_beg_end_flag_idx" % beg_or_end
        return idx

    def decode(self, text_index, text_prob=None, is_remove_duplicate=False):
        """convert text-index into text-label."""
        result_list = []
        [end_idx] = self.get_ignored_tokens()
        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []
            for idx in range(len(text_index[batch_idx])):
                if int(text_index[batch_idx][idx]) == int(end_idx):
                    break
                if is_remove_duplicate:
                    # only for predict
                    if (
                        idx > 0
                        and text_index[batch_idx][idx - 1] == text_index[batch_idx][idx]
                    ):
                        continue
                char_list.append(self.character[int(text_index[batch_idx][idx])])
                if text_prob is not None:
                    conf_list.append(text_prob[batch_idx][idx])
                else:
                    conf_list.append(1)
            text = "".join(char_list)
            result_list.append((text, np.mean(conf_list).tolist()))
        return result_list

    def __call__(self, preds, label=None, *args, **kwargs):
        """
        text = self.decode(text)
        if label is None:
            return text
        else:
            label = self.decode(label, is_remove_duplicate=False)
            return text, label
        """
        preds_idx = preds["rec_pred"]
        if isinstance(preds_idx, paddle.Tensor):
            preds_idx = preds_idx.numpy()
        if "rec_pred_scores" in preds:
            preds_idx = preds["rec_pred"]
            preds_prob = preds["rec_pred_scores"]
        else:
            preds_idx = preds["rec_pred"].argmax(axis=2)
            preds_prob = preds["rec_pred"].max(axis=2)
        text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)
        if label is None:
            return text
        label = self.decode(label, is_remove_duplicate=False)
        return text, label


class SRNLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(SRNLabelDecode, self).__init__(character_dict_path, use_space_char)
        self.max_text_length = kwargs.get("max_text_length", 25)

    def __call__(self, preds, label=None, *args, **kwargs):
        pred = preds["predict"]
        char_num = len(self.character_str) + 2
        if isinstance(pred, paddle.Tensor):
            pred = pred.numpy()
        pred = np.reshape(pred, [-1, char_num])

        preds_idx = np.argmax(pred, axis=1)
        preds_prob = np.max(pred, axis=1)

        preds_idx = np.reshape(preds_idx, [-1, self.max_text_length])

        preds_prob = np.reshape(preds_prob, [-1, self.max_text_length])

        text = self.decode(preds_idx, preds_prob)

        if label is None:
            text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)
            return text
        label = self.decode(label)
        return text, label

    def decode(self, text_index, text_prob=None, is_remove_duplicate=False):
        """convert text-index into text-label."""
        result_list = []
        ignored_tokens = self.get_ignored_tokens()
        batch_size = len(text_index)

        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []
            for idx in range(len(text_index[batch_idx])):
                if text_index[batch_idx][idx] in ignored_tokens:
                    continue
                if is_remove_duplicate:
                    # only for predict
                    if (
                        idx > 0
                        and text_index[batch_idx][idx - 1] == text_index[batch_idx][idx]
                    ):
                        continue
                char_list.append(self.character[int(text_index[batch_idx][idx])])
                if text_prob is not None:
                    conf_list.append(text_prob[batch_idx][idx])
                else:
                    conf_list.append(1)

            text = "".join(char_list)
            result_list.append((text, np.mean(conf_list).tolist()))
        return result_list

    def add_special_char(self, dict_character):
        dict_character = dict_character + [self.beg_str, self.end_str]
        return dict_character

    def get_ignored_tokens(self):
        beg_idx = self.get_beg_end_flag_idx("beg")
        end_idx = self.get_beg_end_flag_idx("end")
        return [beg_idx, end_idx]

    def get_beg_end_flag_idx(self, beg_or_end):
        if beg_or_end == "beg":
            idx = np.array(self.dict[self.beg_str])
        elif beg_or_end == "end":
            idx = np.array(self.dict[self.end_str])
        else:
            assert False, "unsupport type %s in get_beg_end_flag_idx" % beg_or_end
        return idx


class ParseQLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    BOS = "[B]"
    EOS = "[E]"
    PAD = "[P]"

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(ParseQLabelDecode, self).__init__(character_dict_path, use_space_char)
        self.max_text_length = kwargs.get("max_text_length", 25)

    def __call__(self, preds, label=None, *args, **kwargs):
        if isinstance(preds, dict):
            pred = preds["predict"]
        else:
            pred = preds

        char_num = (
            len(self.character_str) + 1
        )  # We don't predict <bos> nor <pad>, with only addition <eos>
        if isinstance(pred, paddle.Tensor):
            pred = pred.numpy()
        B, L = pred.shape[:2]
        pred = np.reshape(pred, [-1, char_num])

        preds_idx = np.argmax(pred, axis=1)
        preds_prob = np.max(pred, axis=1)

        preds_idx = np.reshape(preds_idx, [B, L])
        preds_prob = np.reshape(preds_prob, [B, L])

        if label is None:
            text = self.decode(preds_idx, preds_prob, raw=False)
            return text

        text = self.decode(preds_idx, preds_prob, raw=False)
        label = self.decode(label, None, False)

        return text, label

    def decode(self, text_index, text_prob=None, raw=False):
        """convert text-index into text-label."""
        result_list = []
        ignored_tokens = self.get_ignored_tokens()
        batch_size = len(text_index)

        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []

            index = text_index[batch_idx, :]
            prob = None
            if text_prob is not None:
                prob = text_prob[batch_idx, :]

            if not raw:
                index, prob = self._filter(index, prob)

            for idx in range(len(index)):
                if index[idx] in ignored_tokens:
                    continue
                char_list.append(self.character[int(index[idx])])
                if text_prob is not None:
                    conf_list.append(prob[idx])
                else:
                    conf_list.append(1)

            text = "".join(char_list)
            result_list.append((text, np.mean(conf_list).tolist()))

        return result_list

    def add_special_char(self, dict_character):
        dict_character = [self.EOS] + dict_character + [self.BOS, self.PAD]
        return dict_character

    def _filter(self, ids, probs=None):
        ids = ids.tolist()
        try:
            eos_idx = ids.index(self.dict[self.EOS])
        except ValueError:
            eos_idx = len(ids)  # Nothing to truncate.
        # Truncate after EOS
        ids = ids[:eos_idx]
        if probs is not None:
            probs = probs[: eos_idx + 1]  # but include prob. for EOS (if it exists)
        return ids, probs

    def get_ignored_tokens(self):
        return [self.dict[self.BOS], self.dict[self.EOS], self.dict[self.PAD]]


class SARLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(SARLabelDecode, self).__init__(character_dict_path, use_space_char)

        self.rm_symbol = kwargs.get("rm_symbol", False)

    def add_special_char(self, dict_character):
        beg_end_str = "<BOS/EOS>"
        unknown_str = "<UKN>"
        padding_str = "<PAD>"
        dict_character = dict_character + [unknown_str]
        self.unknown_idx = len(dict_character) - 1
        dict_character = dict_character + [beg_end_str]
        self.start_idx = len(dict_character) - 1
        self.end_idx = len(dict_character) - 1
        dict_character = dict_character + [padding_str]
        self.padding_idx = len(dict_character) - 1
        return dict_character

    def decode(self, text_index, text_prob=None, is_remove_duplicate=False):
        """convert text-index into text-label."""
        result_list = []
        ignored_tokens = self.get_ignored_tokens()

        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []
            for idx in range(len(text_index[batch_idx])):
                if text_index[batch_idx][idx] in ignored_tokens:
                    continue
                if int(text_index[batch_idx][idx]) == int(self.end_idx):
                    if text_prob is None and idx == 0:
                        continue
                    else:
                        break
                if is_remove_duplicate:
                    # only for predict
                    if (
                        idx > 0
                        and text_index[batch_idx][idx - 1] == text_index[batch_idx][idx]
                    ):
                        continue
                char_list.append(self.character[int(text_index[batch_idx][idx])])
                if text_prob is not None:
                    conf_list.append(text_prob[batch_idx][idx])
                else:
                    conf_list.append(1)
            text = "".join(char_list)
            if self.rm_symbol:
                comp = re.compile("[^A-Z^a-z^0-9^\u4e00-\u9fa5]")
                text = text.lower()
                text = comp.sub("", text)
            result_list.append((text, np.mean(conf_list).tolist()))
        return result_list

    def __call__(self, preds, label=None, *args, **kwargs):
        if isinstance(preds, paddle.Tensor):
            preds = preds.numpy()
        preds_idx = preds.argmax(axis=2)
        preds_prob = preds.max(axis=2)

        text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)

        if label is None:
            return text
        label = self.decode(label, is_remove_duplicate=False)
        return text, label

    def get_ignored_tokens(self):
        return [self.padding_idx]


class SATRNLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(SATRNLabelDecode, self).__init__(character_dict_path, use_space_char)

        self.rm_symbol = kwargs.get("rm_symbol", False)

    def add_special_char(self, dict_character):
        beg_end_str = "<BOS/EOS>"
        unknown_str = "<UKN>"
        padding_str = "<PAD>"
        dict_character = dict_character + [unknown_str]
        self.unknown_idx = len(dict_character) - 1
        dict_character = dict_character + [beg_end_str]
        self.start_idx = len(dict_character) - 1
        self.end_idx = len(dict_character) - 1
        dict_character = dict_character + [padding_str]
        self.padding_idx = len(dict_character) - 1
        return dict_character

    def decode(self, text_index, text_prob=None, is_remove_duplicate=False):
        """convert text-index into text-label."""
        result_list = []
        ignored_tokens = self.get_ignored_tokens()

        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []
            for idx in range(len(text_index[batch_idx])):
                if text_index[batch_idx][idx] in ignored_tokens:
                    continue
                if int(text_index[batch_idx][idx]) == int(self.end_idx):
                    if text_prob is None and idx == 0:
                        continue
                    else:
                        break
                if is_remove_duplicate:
                    # only for predict
                    if (
                        idx > 0
                        and text_index[batch_idx][idx - 1] == text_index[batch_idx][idx]
                    ):
                        continue
                char_list.append(self.character[int(text_index[batch_idx][idx])])
                if text_prob is not None:
                    conf_list.append(text_prob[batch_idx][idx])
                else:
                    conf_list.append(1)
            text = "".join(char_list)
            if self.rm_symbol:
                comp = re.compile("[^A-Z^a-z^0-9^\u4e00-\u9fa5]")
                text = text.lower()
                text = comp.sub("", text)
            result_list.append((text, np.mean(conf_list).tolist()))
        return result_list

    def __call__(self, preds, label=None, *args, **kwargs):
        if isinstance(preds, paddle.Tensor):
            preds = preds.numpy()
        preds_idx = preds.argmax(axis=2)
        preds_prob = preds.max(axis=2)

        text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)

        if label is None:
            return text
        label = self.decode(label, is_remove_duplicate=False)
        return text, label

    def get_ignored_tokens(self):
        return [self.padding_idx]


class DistillationSARLabelDecode(SARLabelDecode):
    """
    Convert
    Convert between text-label and text-index
    """

    def __init__(
        self,
        character_dict_path=None,
        use_space_char=False,
        model_name=["student"],
        key=None,
        multi_head=False,
        **kwargs,
    ):
        super(DistillationSARLabelDecode, self).__init__(
            character_dict_path, use_space_char
        )
        if not isinstance(model_name, list):
            model_name = [model_name]
        self.model_name = model_name

        self.key = key
        self.multi_head = multi_head

    def __call__(self, preds, label=None, *args, **kwargs):
        output = dict()
        for name in self.model_name:
            pred = preds[name]
            if self.key is not None:
                pred = pred[self.key]
            if self.multi_head and isinstance(pred, dict):
                pred = pred["sar"]
            output[name] = super().__call__(pred, label=label, *args, **kwargs)
        return output


class PRENLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(PRENLabelDecode, self).__init__(character_dict_path, use_space_char)

    def add_special_char(self, dict_character):
        padding_str = "<PAD>"  # 0
        end_str = "<EOS>"  # 1
        unknown_str = "<UNK>"  # 2

        dict_character = [padding_str, end_str, unknown_str] + dict_character
        self.padding_idx = 0
        self.end_idx = 1
        self.unknown_idx = 2

        return dict_character

    def decode(self, text_index, text_prob=None):
        """convert text-index into text-label."""
        result_list = []
        batch_size = len(text_index)

        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []
            for idx in range(len(text_index[batch_idx])):
                if text_index[batch_idx][idx] == self.end_idx:
                    break
                if text_index[batch_idx][idx] in [self.padding_idx, self.unknown_idx]:
                    continue
                char_list.append(self.character[int(text_index[batch_idx][idx])])
                if text_prob is not None:
                    conf_list.append(text_prob[batch_idx][idx])
                else:
                    conf_list.append(1)

            text = "".join(char_list)
            if len(text) > 0:
                result_list.append((text, np.mean(conf_list).tolist()))
            else:
                # here confidence of empty recog result is 1
                result_list.append(("", 1))
        return result_list

    def __call__(self, preds, label=None, *args, **kwargs):
        if isinstance(preds, paddle.Tensor):
            preds = preds.numpy()
        preds_idx = preds.argmax(axis=2)
        preds_prob = preds.max(axis=2)
        text = self.decode(preds_idx, preds_prob)
        if label is None:
            return text
        label = self.decode(label)
        return text, label


class NRTRLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=True, **kwargs):
        super(NRTRLabelDecode, self).__init__(character_dict_path, use_space_char)

    def __call__(self, preds, label=None, *args, **kwargs):
        if len(preds) == 2:
            preds_id = preds[0]
            preds_prob = preds[1]
            if isinstance(preds_id, paddle.Tensor):
                preds_id = preds_id.numpy()
            if isinstance(preds_prob, paddle.Tensor):
                preds_prob = preds_prob.numpy()
            if preds_id[0][0] == 2:
                preds_idx = preds_id[:, 1:]
                preds_prob = preds_prob[:, 1:]
            else:
                preds_idx = preds_id
            text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)
            if label is None:
                return text
            label = self.decode(label[:, 1:])
        else:
            if isinstance(preds, paddle.Tensor):
                preds = preds.numpy()
            preds_idx = preds.argmax(axis=2)
            preds_prob = preds.max(axis=2)
            text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)
            if label is None:
                return text
            label = self.decode(label[:, 1:])
        return text, label

    def add_special_char(self, dict_character):
        dict_character = ["blank", "<unk>", "<s>", "</s>"] + dict_character
        return dict_character

    def decode(self, text_index, text_prob=None, is_remove_duplicate=False):
        """convert text-index into text-label."""
        result_list = []
        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            char_list = []
            conf_list = []
            for idx in range(len(text_index[batch_idx])):
                try:
                    char_idx = self.character[int(text_index[batch_idx][idx])]
                except:
                    continue
                if char_idx == "</s>":  # end
                    break
                char_list.append(char_idx)
                if text_prob is not None:
                    conf_list.append(text_prob[batch_idx][idx])
                else:
                    conf_list.append(1)
            text = "".join(char_list)
            result_list.append((text, np.mean(conf_list).tolist()))
        return result_list


class ViTSTRLabelDecode(NRTRLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(ViTSTRLabelDecode, self).__init__(character_dict_path, use_space_char)

    def __call__(self, preds, label=None, *args, **kwargs):
        if isinstance(preds, paddle.Tensor):
            preds = preds[:, 1:].numpy()
        else:
            preds = preds[:, 1:]
        preds_idx = preds.argmax(axis=2)
        preds_prob = preds.max(axis=2)
        text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)
        if label is None:
            return text
        label = self.decode(label[:, 1:])
        return text, label

    def add_special_char(self, dict_character):
        dict_character = ["<s>", "</s>"] + dict_character
        return dict_character


class ABINetLabelDecode(NRTRLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(ABINetLabelDecode, self).__init__(character_dict_path, use_space_char)

    def __call__(self, preds, label=None, *args, **kwargs):
        if isinstance(preds, dict):
            preds = preds["align"][-1].numpy()
        elif isinstance(preds, paddle.Tensor):
            preds = preds.numpy()
        else:
            preds = preds

        preds_idx = preds.argmax(axis=2)
        preds_prob = preds.max(axis=2)
        text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)
        if label is None:
            return text
        label = self.decode(label)
        return text, label

    def add_special_char(self, dict_character):
        dict_character = ["</s>"] + dict_character
        return dict_character


class SPINLabelDecode(AttnLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(SPINLabelDecode, self).__init__(character_dict_path, use_space_char)

    def add_special_char(self, dict_character):
        self.beg_str = "sos"
        self.end_str = "eos"
        dict_character = dict_character
        dict_character = [self.beg_str] + [self.end_str] + dict_character
        return dict_character


class VLLabelDecode(BaseRecLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(VLLabelDecode, self).__init__(character_dict_path, use_space_char)
        self.max_text_length = kwargs.get("max_text_length", 25)
        self.nclass = len(self.character) + 1

    def decode(self, text_index, text_prob=None, is_remove_duplicate=False):
        """convert text-index into text-label."""
        result_list = []
        ignored_tokens = self.get_ignored_tokens()
        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            selection = np.ones(len(text_index[batch_idx]), dtype=bool)
            if is_remove_duplicate:
                selection[1:] = text_index[batch_idx][1:] != text_index[batch_idx][:-1]
            for ignored_token in ignored_tokens:
                selection &= text_index[batch_idx] != ignored_token

            char_list = [
                self.character[text_id - 1]
                for text_id in text_index[batch_idx][selection]
            ]
            if text_prob is not None:
                conf_list = text_prob[batch_idx][selection]
            else:
                conf_list = [1] * len(selection)
            if len(conf_list) == 0:
                conf_list = [0]

            text = "".join(char_list)
            result_list.append((text, np.mean(conf_list).tolist()))
        return result_list

    def __call__(self, preds, label=None, length=None, *args, **kwargs):
        if len(preds) == 2:  # eval mode
            text_pre, x = preds
            b = text_pre.shape[1]
            lenText = self.max_text_length
            nsteps = self.max_text_length

            if not isinstance(text_pre, paddle.Tensor):
                text_pre = paddle.to_tensor(text_pre, dtype="float32")

            out_res = paddle.zeros(shape=[lenText, b, self.nclass], dtype=x.dtype)
            out_length = paddle.zeros(shape=[b], dtype=x.dtype)
            now_step = 0
            for _ in range(nsteps):
                if 0 in out_length and now_step < nsteps:
                    tmp_result = text_pre[now_step, :, :]
                    out_res[now_step] = tmp_result
                    tmp_result = tmp_result.topk(1)[1].squeeze(axis=1)
                    for j in range(b):
                        if out_length[j] == 0 and tmp_result[j] == 0:
                            out_length[j] = now_step + 1
                    now_step += 1
            for j in range(0, b):
                if int(out_length[j]) == 0:
                    out_length[j] = nsteps
            start = 0
            output = paddle.zeros(
                shape=[int(out_length.sum()), self.nclass], dtype=x.dtype
            )
            for i in range(0, b):
                cur_length = int(out_length[i])
                output[start : start + cur_length] = out_res[0:cur_length, i, :]
                start += cur_length
            net_out = output
            length = out_length

        else:  # train mode
            net_out = preds[0]
            length = length
            net_out = paddle.concat([t[:l] for t, l in zip(net_out, length)])
        text = []
        if not isinstance(net_out, paddle.Tensor):
            net_out = paddle.to_tensor(net_out, dtype="float32")
        net_out = F.softmax(net_out, axis=1)
        for i in range(0, length.shape[0]):
            if i == 0:
                start_idx = 0
                end_idx = int(length[i])
            else:
                start_idx = int(length[:i].sum())
                end_idx = int(length[:i].sum() + length[i])
            preds_idx = net_out[start_idx:end_idx].topk(1)[1][:, 0].tolist()
            preds_text = "".join(
                [
                    (
                        self.character[idx - 1]
                        if idx > 0 and idx <= len(self.character)
                        else ""
                    )
                    for idx in preds_idx
                ]
            )
            preds_prob = net_out[start_idx:end_idx].topk(1)[0][:, 0]
            preds_prob = paddle.exp(
                paddle.log(preds_prob).sum() / (preds_prob.shape[0] + 1e-6)
            )
            text.append((preds_text, float(preds_prob)))
        if label is None:
            return text
        label = self.decode(label)
        return text, label


class CANLabelDecode(BaseRecLabelDecode):
    """Convert between latex-symbol and symbol-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(CANLabelDecode, self).__init__(character_dict_path, use_space_char)

    def decode(self, text_index, preds_prob=None):
        result_list = []
        batch_size = len(text_index)
        for batch_idx in range(batch_size):
            seq_end = text_index[batch_idx].argmin(0)
            idx_list = text_index[batch_idx][:seq_end].tolist()
            symbol_list = [self.character[idx] for idx in idx_list]
            probs = []
            if preds_prob is not None:
                probs = preds_prob[batch_idx][: len(symbol_list)].tolist()

            result_list.append([" ".join(symbol_list), probs])
        return result_list

    def __call__(self, preds, label=None, *args, **kwargs):
        pred_prob, _, _, _ = preds
        preds_idx = pred_prob.argmax(axis=2)

        text = self.decode(preds_idx)
        if label is None:
            return text
        label = self.decode(label)
        return text, label


class CPPDLabelDecode(NRTRLabelDecode):
    """Convert between text-label and text-index"""

    def __init__(self, character_dict_path=None, use_space_char=False, **kwargs):
        super(CPPDLabelDecode, self).__init__(character_dict_path, use_space_char)

    def __call__(self, preds, label=None, *args, **kwargs):
        if isinstance(preds, tuple):
            if isinstance(preds[-1], dict):
                preds = preds[-1]["align"][-1].numpy()
            else:
                preds = preds[-1].numpy()
        if isinstance(preds, paddle.Tensor):
            preds = preds.numpy()
        else:
            preds = preds
        preds_idx = preds.argmax(axis=2)
        preds_prob = preds.max(axis=2)
        text = self.decode(preds_idx, preds_prob, is_remove_duplicate=False)
        if label is None:
            return text
        label = self.decode(label)
        return text, label

    def add_special_char(self, dict_character):
        dict_character = ["</s>"] + dict_character
        return dict_character


class LaTeXOCRDecode(object):
    """Convert between latex-symbol and symbol-index"""

    def __init__(self, rec_char_dict_path, **kwargs):
        from tokenizers import Tokenizer as TokenizerFast

        super(LaTeXOCRDecode, self).__init__()
        self.tokenizer = TokenizerFast.from_file(rec_char_dict_path)

    def post_process(self, s):
        text_reg = r"(\\(operatorname|mathrm|text|mathbf)\s?\*? {.*?})"
        letter = "[a-zA-Z]"
        noletter = "[\W_^\d]"
        names = [x[0].replace(" ", "") for x in re.findall(text_reg, s)]
        s = re.sub(text_reg, lambda match: str(names.pop(0)), s)
        news = s
        while True:
            s = news
            news = re.sub(r"(?!\\ )(%s)\s+?(%s)" % (noletter, noletter), r"\1\2", s)
            news = re.sub(r"(?!\\ )(%s)\s+?(%s)" % (noletter, letter), r"\1\2", news)
            news = re.sub(r"(%s)\s+?(%s)" % (letter, noletter), r"\1\2", news)
            if news == s:
                break
        return s

    def decode(self, tokens):
        if len(tokens.shape) == 1:
            tokens = tokens[None, :]
        dec = [self.tokenizer.decode(tok) for tok in tokens]
        dec_str_list = [
            "".join(detok.split(" "))
            .replace("Ġ", " ")
            .replace("[EOS]", "")
            .replace("[BOS]", "")
            .replace("[PAD]", "")
            .strip()
            for detok in dec
        ]
        return [self.post_process(dec_str) for dec_str in dec_str_list]

    def __call__(self, preds, label=None, mode="eval", *args, **kwargs):
        if mode == "train":
            preds_idx = np.array(preds.argmax(axis=2))
            text = self.decode(preds_idx)
        else:
            text = self.decode(np.array(preds))
        if label is None:
            return text
        label = self.decode(np.array(label))
        return text, label