We present PBFormer, an efficient yet powerful scene text detector that
unifies the transformer with a novel text shape representation Polynomial Band
(PB). The representation has four polynomial curves to fit a text's top,
bottom, left, and right sides, which can capture a text with a complex shape by
varying polynomial coefficients. PB has appealing features compared with
conventional representations: 1) It can model different curvatures with a fixed
number of parameters, while polygon-points-based methods need to utilize a
different number of points. 2) It can distinguish adjacent or overlapping texts
as they have apparent different curve coefficients, while segmentation-based or
points-based methods suffer from adhesive spatial positions. PBFormer combines
the PB with the transformer, which can directly generate smooth text contours
sampled from predicted curves without interpolation. A parameter-free
cross-scale pixel attention (CPA) module is employed to highlight the feature
map of a suitable scale while suppressing the other feature maps. The simple
operation can help detect small-scale texts and is compatible with the
one-stage DETR framework, where no postprocessing exists for NMS. Furthermore,
PBFormer is trained with a shape-contained loss, which not only enforces the
piecewise alignment between the ground truth and the predicted curves but also
makes curves' positions and shapes consistent with each other. Without bells
and whistles about text pre-training, our method is superior to the previous
state-of-the-art text detectors on the arbitrary-shaped text datasets.

我们提出了 PBFormer，一种高效而强大的场景文本检测器，将变压器和一种新颖的文本形状表示多项式带（PB）结合起来。

PBFormer：使用多项式带变换器捕捉复杂场景文字形状

PBFormer: Capturing Complex Scene Text Shape with Polynomial Band  Transformer

In this paper, we propose a refined scene text detector with a \textit{novel}
Feature Enhancement Network (FEN) for Region Proposal and Text Detection
Refinement. Retrospectively, both region proposal with \textit{only} $3\times
3$ sliding-window feature and text detection refinement with \textit{single
scale} high level feature are insufficient, especially for smaller scene text.
Therefore, we design a new FEN network with \textit{task-specific},
\textit{low} and \textit{high} level semantic features fusion to improve the
performance of text detection. Besides, since \textit{unitary}
position-sensitive RoI pooling in general object detection is unreasonable for
variable text regions, an \textit{adaptively weighted} position-sensitive RoI
pooling layer is devised for further enhancing the detecting accuracy. To
tackle the \textit{sample-imbalance} problem during the refinement stage, we
also propose an effective \textit{positives mining} strategy for efficiently
training our network. Experiments on ICDAR 2011 and 2013 robust text detection
benchmarks demonstrate that our method can achieve state-of-the-art results,
outperforming all reported methods in terms of F-measure.

本文提出了一种经过改进的场景文本检测器，它包含一个新颖的特征增强网络（FEN）和适应性加权的定位敏感 RoI 池层，以提高对小型场景文本的检测精度，同时，也提出了一种有效的样本平衡策略来训练我们的网络，并在 ICDAR 2011 和 2013 鲁棒文本检测基准测试中得到了最先进的结果。

特征增强网络：一种精制的场景文本检测器

Feature Enhancement Network: A Refined Scene Text Detector

This paper presents an end-to-end trainable fast scene text detector, named
TextBoxes, which detects scene text with both high accuracy and efficiency in a
single network forward pass, involving no post-process except for a standard
non-maximum suppression. TextBoxes outperforms competing methods in terms of
text localization accuracy and is much faster, taking only 0.09s per image in a
fast implementation. Furthermore, combined with a text recognizer, TextBoxes
significantly outperforms state-of-the-art approaches on word spotting and
end-to-end text recognition tasks.

该研究论文提出了一种名为 TextBoxes 的端到端可训练快速场景文本检测器，它能够在一次网络正向传递中高效准确地检测场景文本，除了标准的非极大值抑制外，不需要任何后处理。结合文本识别器后，TextBoxes 在单词定位和端到端文本识别任务方面显着优于现有方法。