Single Image Super-resolution Reconstruction Research Articles

Perceptual super-resolution in multiple sclerosis MRI.

Magnetic resonance imaging (MRI) is crucial for diagnosing and monitoring of multiple sclerosis (MS) as it is used to assess lesions in the brain and spinal cord. However, in real-world clinical settings, MRI scans are often acquired with thick slices, limiting their utility for automated quantitative analyses. This work presents a single-image super-resolution (SR) reconstruction framework that leverages SR convolutional neural networks (CNN) to enhance the through-plane resolution of structural MRI in people with MS (PwMS). Our strategy involves the supervised fine-tuning of CNN architectures, guided by a content loss function that promotes perceptual quality, as well as reconstruction accuracy, to recover high-level image features. Extensive evaluation with MRI data of PwMS shows that our SR strategy leads to more accurate MRI reconstructions than competing methods. Furthermore, it improves lesion segmentation on low-resolution MRI, approaching the performance achievable with high-resolution images. Results demonstrate the potential of our SR framework to facilitate the use of low-resolution retrospective MRI from real-world clinical settings to investigate quantitative image-based biomarkers of MS.

Accurate Inspection and Super-Resolution Reconstruction for Additive Manufactured Defects Based on Stokes Vector Method and Deep Learning

Defects in additive manufacturing processes are closely related to the mechanical and physical properties of the components. However, the extreme conditions of high temperatures, intense light, and powder during the manufacturing process present significant challenges for defect detection. Additionally, the high reflectivity of metallic components can cause pixels in image sensors to become overexposed, resulting in the loss of many defect signals. Thus, this paper mainly focuses on proposing an accurate inspection and super-resolution reconstruction method for additive manufactured defects based on Stokes vector and deep learning, where the Stokes vectors, polarization degree, and polarization angles of the inspected defects are effectively utilized to suppress the high reflectivity of metallic surfaces, enhance the contrast of defect regions, and highlight the boundaries of defects. Furthermore, a modified SRGAN model designated SRGAN-H is presented by employing an additional convolutional layer and activation functions, including Harswish and Tanh, to accelerate the convergence of the SRGAN-H network and improve the reconstruction of the additive manufactured defect region. The experiment results demonstrated that the SRGAN-H model outperformed SRGAN and traditional SR reconstruction algorithms in terms of the images of Stokes vectors, polarization degree, and polarization angles. For the scratch and hole test sets, the PSNR values were 33.405 and 31.159, respectively, and the SSIM values were 0.890 and 0.896, respectively. These results reflect the effectiveness of the SRGAN-H model in super-resolution reconstruction of scratch and hole images. For the scratch and hole images chosen in this study, the PSNR values of SRGAN-H for single image super-resolution reconstruction ranged from 31.86786 to 43.82374, higher than the results obtained by the pre-improvement SRGAN algorithm.

A novel single image super-resolution reconstruction model based on edge-enhanced Siamese generative adversarial networks

Abstract Currently, most image super-resolution (SR) reconstruction algorithms are supervised, improving the overall visual quality of images based on a large amount of paired low-resolution (LR) and high-resolution (HR) image. However, collecting a large number of paired datasets is challenging, and the quality of the dataset can influence the reconstruction results. Although unsupervised methods have gained significant performance based on synthetic datasets, their effectiveness is relatively poor when applied to real-world or natural data. Focusing on those aforementioned issues, a novel image SR reconstruction algorithm of Edge-enhanced Siamese Generative Adversarial Network (EeSiGAN) is proposed. EeSiGAN belongs to the unsupervised category and does not require the involvement of HR images. Firstly, employing the Siamese GAN as the overall framework ensures the continuous consistency of image feature maps through the collaborative effect of support and main networks. Secondly, fusing the results of the two branches by using the Multi- scale Channel Attention Feature Fusion (MsCAFF) module. In addition, an Edge- enhanced Feature Distillation Block (EFDB) is introduced to enhance edge information in images and optimize the capability in feature extraction of network. Finally, Directional Variance Attention (DiVA) mechanism is used to obtain long-range spatial dependencies and simultaneously utilize inter-channel dependencies to achieve a more discriminative representation, thereby enhancing the overall quality of the recovered images. Extensive experimental results on synthetic and real datasets demonstrate that compared to other state-of-the-art unsupervised SR networks, the proposed EeSiGAN algorithm exhibits better performance in reconstructing images, producing clearer details and textures in the enlarged images.

Dual residual and large receptive field network for lightweight image super-resolution

In recent years, there has been rapid progress in single-image super-resolution (SISR) reconstruction technology based on deep learning, but many methods face challenges in practical application due to their excessive computational requirements. To address this issue, numerous lightweight super-resolution (SR) methods have been proposed. Convolutional neural networks (CNNs) have demonstrated outstanding performance in lightweight SR reconstruction tasks. However, existing CNN-based lightweight SR networks still suffer from redundancy due to the use of small convolutional kernels and deeper network architectures for feature extraction. To solve these problems, we propose a novel network called Dual Residual and Large Receptive Field Network (DRLN), which includes two main designs. Firstly, a Large Receptive Field Feature Extraction Block (LRFEB) is proposed, which concatenates large kernel depth separable convolutions and large kernel depth separable dilated convolutions, effectively capturing spatial contextual information without increasing the number of parameters or computational burden, and enhancing the overall performance of the model. Secondly, in the Efficient Feature Distillation Block (EFDB), we innovatively propose a dual residual structure, which greatly improve the learning ability and feature expression richness of the network, and significantly improve the reconstruction performance. Extensive experiments demonstrate that DRLN surpasses BSRN which is the champion of the model complexity track of the NTIRE 2022 Efficient SR Challenge on all benchmark datasets, with fewer parameters and less computation.

Super-resolution reconstruction of single image for latent features

Single-image super-resolution (SISR) typically focuses on restoring various degraded low-resolution (LR) images to a single high-resolution (HR) image. However, during SISR tasks, it is often challenging for models to simultaneously maintain high quality and rapid sampling while preserving diversity in details and texture features. This challenge can lead to issues such as model collapse, lack of rich details and texture features in the reconstructed HR images, and excessive time consumption for model sampling. To address these problems, this paper proposes a Latent Feature-oriented Diffusion Probability Model (LDDPM). First, we designed a conditional encoder capable of effectively encoding LR images, reducing the solution space for model image reconstruction and thereby improving the quality of the reconstructed images. We then employed a normalized flow and multimodal adversarial training, learning from complex multimodal distributions, to model the denoising distribution. Doing so boosts the generative modeling capabilities within a minimal number of sampling steps. Experimental comparisons of our proposed model with existing SISR methods on mainstream datasets demonstrate that our model reconstructs more realistic HR images and achieves better performance on multiple evaluation metrics, providing a fresh perspective for tackling SISR tasks.

A Lightweight Pyramid Feature Fusion Network for Single Image Super-Resolution Reconstruction

A Lightweight Pyramid Feature Fusion Network for Single Image Super-Resolution Reconstruction

Single image super-resolution reconstruction based on split-attention networks

Single image super-resolution reconstruction based on split-attention networks

Single-image super-resolution reconstruction based on phase-aware visual multi-layer perceptron (MLP).

Many advanced super-resolution reconstruction methods have been proposed recently, but they often require high computational and memory resources, making them incompatible with low-power devices in reality. To address this problem, we propose a simple yet efficient super-resolution reconstruction method using waveform representation and multi-layer perceptron (MLP) for image processing. Firstly, we partition the original image and its down-sampled version into multiple patches and introduce WaveBlock to process these patches. WaveBlock represents patches as waveform functions with amplitude and phase and extracts representative feature representations by dynamically adjusting phase terms between tokens and fixed weights. Next, we fuse the extracted features through a feature fusion block and finally reconstruct the image using sub-pixel convolution. Extensive experimental results demonstrate that SRWave-MLP performs excellently in both quantitative evaluation metrics and visual quality while having significantly fewer parameters than state-of-the-art efficient super-resolution methods.

A review of single image super-resolution reconstruction based on deep learning

A review of single image super-resolution reconstruction based on deep learning

MFFN: Multi‐path feedback fusion network for lightweight image super resolution

AbstractRecently, convolutional neural network (CNN) has shown great power in single image super resolution (SISR) reconstruction, and achieving significant improvements over traditional methods. Despite the great success of these CNN‐based methods, direct application of these methods to some edge devices is impractical due to the large computational overhead required. To address this problem, a novel, lightweight SISR network focusing on speed and accuracy, called the multi‐path feedback fusion network (MFFN), has been designed in this paper. Specifically, in order to extract features more effectively, the authors propose a novel fusion attention feedback block (FAFB) as the main building block of MFFN. The FAFB consists of a backbone branch and several hierarchical branches. The backbone branch is composed of stacked enhanced pixel attentional blocks (EPAB), which are responsible for incremental deep feature learning on the feature map. And the hierarchical branches are responsible for extracting feature maps with different sizes of receptive fields and fusing these feature maps with the features extracted from the trunk branches to achieve multi‐scale feature learning, which the authors refer to this design as the multi‐scale fusion block (MSFB). Extra enhancement information (EIE) is added to each EPAB input, which enables the backbone branch to learn more effectively. On the other hand, the outputs of the cascade branches are further complemented by an additional feedback fusion enhancement block (FFEB) before being fused with the output of the trunk branches to achieve more comprehensive and accurate feature learning. Numerous experiments have shown that MFFN achieves higher accuracy than other state‐of‐the‐art methods on benchmark test sets.

Improved wavelet prediction superresolution reconstruction based on U‐Net

AbstractDeep learning can be used to achieve single‐image superresolution (SR) reconstruction. To address problems encountered during this process, such as the number of network parameters, high training requirements on equipment performance, and inability to downsample certain SR images accurately, an image SR reconstruction algorithm based on deep residual network optimization is proposed. The model introduces wavelet transforms based on the original U‐Net, where the U‐Net is trained to obtain SR wavelet feature images at multiple scales simultaneously. This approach reduces the mapping space for the network to learn low‐ to high‐resolution image mapping, which in turn reduces the training difficulty of the model. In terms of network details, the inverse wavelet transform is used in image upsampling to enhance the sparsity of the reconstruction layer in the original network. The network structure of the U‐Net upsampling is adjusted slightly to enable the network to distinguish wavelet images from feature images, thereby improving the richness of the features extracted by the model. The experimental results show that the peak signal‐to‐noise ratio (PSNR) of the fourfold SR model is 32.35 and 28.68 on the Set5 and Set14 validation sets, respectively. Compared with networks that use wavelet prediction mechanisms, such as the deep wavelet prediction SR (DWSR) and deep wavelet prediction‐based residual SR (DWRSR) models, the PSNR for all the tested public datasets is improved by 0.5. The method yields superior results in terms of both visual effect and PSNR, demonstrating the feasibility of the wavelet prediction mechanism in SR reconstruction and thus offering application value and research significance.

DVDR-SRGAN: Differential Value Dense Residual Super-Resolution Generative Adversarial Network

In the field of single-image super-resolution reconstruction, GAN can obtain the image texture more in line with the human eye. However, during the reconstruction process, it is easy to generate artifacts, false textures, and large deviations in details between the reconstructed image and the Ground Truth. In order to further improve the visual quality, we study the feature correlation between adjacent layers and propose a differential value dense residual network to solve this problem. We first use the deconvolution layer to enlarge the features, then extract the features through the convolution layer, and finally make a difference between the features before being magnified and the features after being extracted so that the difference can better reflect the areas that need attention. In the process of extracting the differential value, using the dense residual connection method for each layer can make the magnified features more complete, so the differential value obtained is more accurate. Next, the joint loss function is introduced to fuse high-frequency information and low-frequency information, which improves the visual effect of the reconstructed image to a certain extent. The experimental results on Set5, Set14, BSD100, and Urban datasets show that our proposed DVDR-SRGAN model is improved in terms of PSNR, SSIM, and LPIPS compared with the Bicubic, SRGAN, ESRGAN, Beby-GAN, and SPSR models.

A novel lightweight multi-dimension feature fusion network for single-image super-resolution reconstruction

A novel lightweight multi-dimension feature fusion network for single-image super-resolution reconstruction

Image Super-Resolution Reconstruction Based on Residual Convolution and Double Attention Mechanism

Currently, single-image super-resolution reconstruction based on deep learning has achieved good results. To address the problems that most networks will have long training time, weak image learning ability and not fully utilizing the high frequency information of images, an image super-resolution reconstruction method based on residual convolution and double attention mechanism is proposed. The model performs deep feature extraction of the image by cascading deep convolutional networks, introduces local residual blocks to solve the model degradation brought by too many network parameters, and embeds the dual attention mechanism module in the residual blocks for adaptive calibration to adjust the feature map weights of each channel and the spatial correlation between features, so as to obtain deep texture detail information and reconstruct the feature image by sub-pixel convolutional layers to up sampling to reconstruct the high-resolution image. In the test sets of Set5 and Set14, peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) are used as evaluation indexes, while comparing SRCNN, FSRCNN and VDSR methods all reconstructed images with better results. The experimental results show that the method can effectively improve the utilization of high-frequency feature information and can increase the reconstruction capability of the images to a certain extent.

Single Image Super-Resolution Reconstruction with Preservation of Structure and Texture Details

In recent years, deep-learning-based single image super-resolution reconstruction has achieved good performance. However, most existing methods pursue a high peak signal-to-noise ratio (PSNR), while ignoring the quality of the structure and texture details, resulting in unsatisfactory performance of the reconstruction results in terms of human subjective perception. To solve this issue, this paper proposes a structure- and texture-preserving image super-resolution reconstruction method. Specifically, two different network branches are used to extract features for image structure and texture details. A dual-coordinate direction perception attention (DCDPA) mechanism is designed to highlight structure and texture features. The attention mechanism fully considers the complementarity and directionality of multi-scale image features and effectively avoids information loss and possible distortion of image structure and texture details during image reconstruction. Additionally, a cross-fusion mechanism is designed to comprehensively utilize structure and texture information for super-resolution image reconstruction, which effectively integrates the structure and texture details extracted by the two branch networks. Extensive experiments verify the effectiveness of the proposed method and its superiority over existing methods.

Single-image super-resolution reconstruction for continuous-wave terahertz imaging systems

Single-image super-resolution reconstruction for continuous-wave terahertz imaging systems

Single image super‐resolution based on sparse representation using edge‐preserving regularization and a low‐rank constraint

Sparse representation-based non-local self-similarity approaches have demonstrated promising performance in single image super-resolution reconstruction. This type of method, however, cannot always effectively preserve the key details of an image, resulting in edge artifacts and local structure blurring. To better preserve the image edge information, in this paper, a sparse representation super-resolution method based on non-local self-similarity is proposed. First, we impose slide window gradient domain guided filtering on both the low-resolution input image and the degraded restored image. Then, we utilize their difference as an edge-preserving regularization term and incorporate this regularization term into the non-local self-similarity-based sparse representation model to build a sparse coding model, which can enhance the restored high-resolution image patches’ detail information. Finally, the iterative threshold algorithm is used to calculate the sparse representation coefficients so that a high-resolution image can be estimated. Furthermore, to explore the potential structures of the subspaces spanned by similar patches, we enforce a low-rank matrix recovery technique on the generated super-resolution image, which can further refine the reconstruction quality. Experimental results prove that the new approach preserves the critical edge structures while suppressing noise and exceeding some popular methods both quantitatively and qualitatively.

Lightweight Multi-Attention Fusion Network for Image Super-Resolution

Single image super-resolution reconstruction (SISR) is one of the important techniques in computer vision and image processing. Most of the existing SISR methods adopt equal processing for different spatial domains and channel domains, resulting in a large amount of computational resources wasted on unimportant features. In order to address these problems, a novel lightweight multi-attention fusion network (LMAFN) is proposed, in which the multiple attention fusion block allocates computational resources more efficiently by capturing the weight information implied by the channel domain and the spatial domain separately, thus effectively reducing the number of parameters. The synthetic channel attention block in the multiple attention fusion block makes full use of inter-channel correlation by introducing both global standard deviation pooling and maximum pooling. Global features are fused through residual linking to alleviate the problem of high frequency information loss. Experimental results on several benchmark datasets show that the proposed method effectively reduces the number of parameters and computational effort without excessive loss of reconstruction performance, and achieves better performance than the compared models.

Super-Resolution Reconstruction of Single Image Combining Bionic Eagle-Eye and Multi-scale

Super-Resolution Reconstruction of Single Image Combining Bionic Eagle-Eye and Multi-scale

Image Super-Resolution Reconstruction Method for Lung Cancer CT-Scanned Images Based on Neural Network.

The super-resolution (SR) reconstruction of a single image is an important image synthesis task especially for medical applications. This paper is studying the application of image segmentation for lung cancer images. This research work is utilizing the power of deep learning for resolution reconstruction for lung cancer-based images. At present, the neural networks utilized for image segmentation and classification are suffering from the loss of information where information passes through one layer to another deep layer. The commonly used loss functions include content-based reconstruction loss and generative confrontation network. The sparse coding single-image super-resolution reconstruction algorithm can easily lead to the phenomenon of incorrect geometric structure in the reconstructed image. In order to solve the problem of excessive smoothness and blurring of the reconstructed image edges caused by the introduction of this self-similarity constraint, a two-layer reconstruction framework based on a smooth layer and a texture layer is proposed for a medical application of lung cancer. This method uses a global nonzero gradient number constrained reconstruction model to reconstruct the smooth layer. The proposed sparse coding method is used to reconstruct high-resolution texture images. Finally, a global and local optimization models are used to further improve the quality of the reconstructed image. An adaptive multiscale remote sensing image super-division reconstruction network is designed. The selective core network and adaptive gating unit are integrated to extract and fuse features to obtain a preliminary reconstruction. Through the proposed dual-drive module, the feature prior drive loss and task drive loss are transmitted to the super-resolution network. The proposed work not only improves the subjective visual effect but the robustness has also been enhanced with more accurate construction of edges. The statistical evaluators are used to test the viability of the proposed scheme.