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基于图像增强的低照度人脸检测

李钟华,白云起,王雪津,黄雷雷,林初俊,廖诗宇   

  1. 福建理工大学计算机科学与数学学院
  • 收稿日期:2023-09-05 修回日期:2023-10-18 发布日期:2023-12-18
  • 通讯作者: 王雪津
  • 基金资助:
    福建省自然科学基金

Low illumination face detection based on image enhancement

  • Received:2023-09-05 Revised:2023-10-18 Online:2023-12-18

摘要: 摘 要: 在光照不足的环境下捕获的图像存在亮度、对比度低的问题,同时带有大量噪声。目前人脸检测技术已趋于成熟,但在低照度等极端情况下的人脸检测精度通常很低。针对人脸检测模型在低照度环境下出现的检测性能明显降低这一问题,提出了一种基于图像增强的人脸检测方法。首先,采用图像增强方法对低照度图像进行预处理,以增强人脸的有效特征信息。其次,在模型主干网络后引入注意力机制,以提升网络对人脸区域的关注,并同时降低非均匀光照与噪声带来的负面影响。此外,引入了注意力边界框损失函数(Wise-IOU),以提升网络对低质量人脸的检测准确率。最后,使用更有效的特征融合模块代替模型原有结构。改进模型在低照度人脸数据集 DARK FACE 上的检测精度 AP@0.5 相较于原始算法提升了 2.4 个百分点。实验结果表明,所提出的改进方法能够在不引入额外参数与计算量的同时提升人脸检测模型在低照度环境下的人脸检测能力。同时在其他两个低照度人脸数据集上的结果表明本文提出方法的有效性与鲁棒性,适用于不同场景下的低照度人脸检测。

关键词: 人脸检测, 图像增强, 注意力机制, 损失函数, 低照度环境

Abstract: Abstract: Images captured in low-light environments suffer from low brightness, low contrast, and a lot of noise. At present, face detection technology has become mature, but the accuracy of face detection in extreme conditions such as low illumination is usually very low. Aiming at the problem that the detection performance of the face detection model is significantly reduced in low-light environment, a face detection method based on image enhancement is proposed. First, image enhancement methods are used to preprocess low-illumination images to enhance the effective feature information of human faces. Secondly, the attention mechanism is introduced after the model backbone network to enhance the network's attention to the face area, and at the same time reduce the negative impact of non-uniform illumination and noise. In addition, an attentional bounding box loss function (Wise-IOU) is introduced to improve the detection accuracy of the network for low-quality faces. Finally, a more effective feature fusion module is used to replace the original structure of the model. Compared with the original algorithm, the detection accuracy AP@0.5 of the improved model on the low-light face dataset DARK FACE is improved by 2.4 percentage points. Experimental results show that the proposed improved method can improve the face detection ability of the face detection model in low-light environments without introducing additional parameters and calculations. At the same time, the results on the other two low-light face datasets show the effectiveness and robustness of the method proposed in this paper, which is suitable for low-light face detection in different scenarios.

Key words: Keywords: face detection, image enhancement, attention mechanism, loss function, low illumination environment

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