The objective of this research is to enhance the quality and accuracy of information extracted from coal mine images, which are often degraded by high dust concentrations and uneven lighting conditions. These challenging environmental conditions introduce noise, reduce local contrast, and lead to the loss of fine details and edge textures, ultimately compromising the visual quality and the reliability of information extraction. Aiming to address these challenges, this study proposes a self-supervised coal mine image denoising algorithm based on adaptive masking. Designed to handle a wide range of noise levels and types, this algorithm aims to restore the original integrity of the image while preserving critical visual features. The proposed algorithm is divided into three main components: adaptive masking, mask integration, and an adaptive integrated loss function. Each component plays a vital role in enhancing the denoising process, ensuring that the final output is accurate and visually appealing.
The adaptive masking component is the cornerstone of the proposed algorithm, enabling segmented processing of coal mine images. This segmentation not only reduces computational overhead but also allows for more targeted and effective denoising. By dividing each image into smaller blocks, the algorithm can analyze and process each section independently, thereby improving the overall efficiency of the denoising process. The module operates by sequentially applying a mask to the edge and corner pixels of each block, while deliberately excluding the central pixels. This method prevents the network from performing a trivial identity mapping that fails to enhance image quality. Instead, this approach introduces data variability that boosts the generalization capability and robustness of the neural network model, making it adaptable to previously unknown images. The adaptive nature of the mask ensures that the module responds dynamically to varying noise levels and image features. By analyzing local variance and texture complexity, the mask can adaptively determine the optimal masking strategy for each block. This tailored approach ensures that the denoising process is responsive to the specific characteristics of each image, substantially improving its effectiveness. Subsequently, once the masking process is complete, the mask integration module is employed. This module is responsible for fusing the neural network’s output with the masked areas to reconstruct a coherent and denoised image. The integration involves calculating the Hadamard product (element-wise multiplication) between the network’s output and the masked image. This strategic operation enhances the network’s capability to distinguish between actual image content and noise, especially around edges and texture boundaries. In this stage, considering local and global features of the coal mine images is crucial. Effective integration of these features allows the algorithm effectively interpret image context, leading in denoised outputs that are coherent and structurally complete. The mask integration module also ensures that denoised areas seamlessly blend into the rest of the image, preserving the overall visual flow and structural integrity. Furthermore, this module incorporates a quality evaluation mechanism to assess the effectiveness of the integration. The feedback from these evaluations is used to iteratively refine the integration process. The final component of the algorithm is an adaptive integrated loss function, which guides the model during training. This loss function is specifically designed to address the unique challenges of coal mine image denoising, including complex noise patterns and the need to preserve subtle image details. The adaptive integrated loss uses the integrated image as a training label, allowing the model to learn effectively from the differences between the noisy input images and the denoised outputs. Additionally, by incorporating the original noisy image, the loss function increases the model’s sensitivity to signal changes, enhancing its adaptability across various denoising scenarios and noise conditions.
The proposed algorithm was rigorously tested using an underground coal mine image dataset alongside four additional public datasets, including Kodak24 (Kodak lossless true color image suite), BSD300 (Berkeley segmentation dataset 300), and BSDS500 (Berkeley segmentation dataset 500). The experiments were specifically designed to simulate real-world conditions, with a particular emphasis on dimly lit environments commonly encountered in coal mines. The results of these experiments demonstrated that the algorithm substantially outperformed other comparative denoising algorithms, in terms of subjective evaluations and objective metrics such as peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM). In tunnel scenes with a high level of Gaussian noise (level 50), the algorithm achieved substantial improvements in PSNR/SSIM values compared to existing methods such as B2U and NBR2NBR, with increases of 4.2 dB/0.055 and 2.99 dB/0.077, respectively. Furthermore, when tested on images corrupted with Gaussian noise levels ranging from 5 to 50 on the public datasets, the algorithm consistently demonstrated substantial PSNR improvements over the second-best method, with increases of 1.09%, 0.72%, and 0.68% for Kodak24, BSD300, and BSDS500, respectively.
The proposed self-supervised denoising algorithm has demonstrated a strong capability to remove noise while preserving overall image information from single coal mine images, across various noise levels and types. This finding highlights the algorithm’s robustness and generalization capabilities, making it a promising tool for real-world applications in coal mine monitoring and safety systems. The effectiveness of the algorithm in enhancing image quality and improving the accuracy of information extraction, even under challenging conditions, underscores its potential to make a substantial contribution to the field of coal mine image processing and analysis.The code in this paper can be obtained by https://www.sciclb.cn/anonymous/skpswk56.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |