Geometric Transformation Combined with Image Enhancement for Small Target Detection in Aerial Images

doi:10.3778/j.issn.1002-8331.2412-0294

Abstract

Abstract: Aerial image small target detection is complex, leading to a decline in detection metrics. An algorithm combining geometric transformations and image enhancement is proposed. Using YOLOv8n as the baseline, DCNv2-CA-GEO extracts spatial and channel features in parallel, dynamically adjusting the convolutional and pooling kernels to quickly adapt to geometric changes. SPD-OK-CSP adjusts channel dimensions, capturing fine-grained features and enhancing image quality. Dysample optimizes upsampling, while Dyhead improves detection head performance. The Inner-Wise-MPD-IoU strategy balances sample features and optimizes generalization. Evaluated by mAP@0.5, mAP@0.5:0.95, Precision, and Recall, experiments on VisDrone2021 show improvements of 6.1 percentage points in mAP@0.5, 4.4 percentage points in mAP@0.5:0.95, 6.0 percentage points in Precision, and 5.0 percentage points in Recall. On LEVIR-Ship, the improvements are 3.4 percentage points in mAP@0.5, 2.2 percentage points in mAP@0.5:0.95, 3.1 percentage points in Precision, and 5.3 percentage points in Recall. Generalization tests on VOC2007+2012 demonstrate enhancements of 2.0 percentage points in mAP@0.5, 4.3 percentage points in mAP@0.5:0.95, 1.5 percentage points in Precision, and 3.1 percentage points in Recall, indicating good robustness.

Key words: aerial image, small target detection, YOLOv8n, SPDConv, Omni-Kernel, DCNv2, Dyhead

摘要： 航拍图像小目标检测场景复杂，检测指标下降，提出几何变化结合图像增强的航拍图像小目标检测算法。以YOLOv8n为基线，DCNv2-CA-GEO并行提取空间特征和通道特征，动态调整卷积核和池化核，快速适应几何变化；SPD-OK-CSP调整通道维度，捕捉细粒度特征，跨阶段全局特征感知，多尺度特征学习，提高图像增强；Dysample动态调整差分采样点，优化上采样计算；Dyhead动态调整特征张量维度，整合上下文信息，优化检测头性能；Inner-Wise-MPD-IoU多视角增益分配策略，平衡不同质量样本特征，准确回归真实框，优化泛化能力。评价指标mAP@0.5、mAP@0.5：0.95、Precision、Recall，消融和对比实验在VisDrone2021上分别提升6.1、4.4、6.0、5.0个百分点，在LEVIR-Ship上分别提升3.4、2.2、3.1、5.3个百分点，优于基线算法和次优算法；泛化实验在VOC2007+2012上分别提升2.0、4.3、1.5、3.1个百分点，鲁棒性良好。

关键词: 航拍图像, 小目标检测, YOLOv8n, SPDConv, Omni-Kernel, DCNv2, Dyhead

QI Xiangming, LI Xiaolong. Geometric Transformation Combined with Image Enhancement for Small Target Detection in Aerial Images[J]. Computer Engineering and Applications, 2025, 61(18): 218-230.

齐向明, 李晓龙. 几何变化结合图像增强的航拍图像小目标检测算法[J]. 计算机工程与应用, 2025, 61(18): 218-230.

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