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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>GANs in Noisy</article-title>
      </title-group>
      <contrib-group>
        <aff id="aff0">
          <label>0</label>
          <institution>IVUS2024: Information Society and University Studies 2024</institution>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Silesian University of Technology</institution>
          ,
          <addr-line>Akademicka 2A, 44-100, Gliwice</addr-line>
          ,
          <country country="PL">Poland</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>University of L'Aquila</institution>
          ,
          <addr-line>Via Vetoio, 40, 67100 Coppito AQ</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>This paper explores the development and optimization of generative adversarial networks (GANs) for generating images from noisy inputs. Generative Adversarial Networks (GANs), consisting of a generator and a discriminator, are highly effective models for producing realistic synthetic images. This research integrates noise into the GAN framework to enhance image generation. We review existing literature on GANs and their applications, propose a novel GAN architecture for handling noisy inputs, and implement this method in Python. Experiments conducted on the Face Mask Lite and Celebrity Faces Image datasets demonstrate the effectiveness of our approach. The paper concludes with a discussion of the results and suggestions for future research directions.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Artificial Intelligence (AI)</kwd>
        <kwd>Neural Networks (NN)</kwd>
        <kwd>Generative Adversarial Networks (GANs)</kwd>
        <kwd>Deep Learning</kwd>
        <kwd>Machine Learning</kwd>
        <kwd>Convolutional Neural Networks (CNNs)</kwd>
        <kwd>Image Processing (IP)</kwd>
        <kwd>Artificial Neural Networks (ANNs)</kwd>
        <kwd>Noisy Image Inputs</kwd>
        <kwd>Image Generation</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        In recent years, artificial intelligence has achieved remarkable progress, particularly in the field of
computer vision. Deep learning methods, including GANs, have played a crucial role in
creating realistic images [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. People particularly note GANs for their ability to learn from and
generate images that closely mimic the training data. However, traditional GANs often struggle
with noisy input data, which can compromise the quality of the generated images [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. Image
processing across various domains—including medical imaging [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], surveillance [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ], and satellite
imagery [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] faces significant challenges due to noise introduced during acquisition, transmission, or
storage. This noise degrades the quality of raw image data, reducing the effectiveness of
conventional image processing algorithms. Therefore, developing robust generative models
that can produce high-quality images from noisy input data is crucial. This study investigates
how noise handling mechanisms can be integrated into GAN architectures to improve their
resilience to noisy data. We aim to improve the diversity and robustness of the generated images
by investigating how we can leverage adversarial training to learn noise-aware representations. This
approach not only offers practical benefits but also advances our understanding of deep learning
principles. Through both theoretical and empirical research, this work aims to show how
noiseaware GANs could be useful in real-life situations where data is often noisy.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Context and Related Literature</title>
      <p>
        Since their introduction by Goodfellow et al. in 2014 [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ], generative adversarial networks (GANs) have
transformed image synthesis. Two neural networks, a generator and a discriminator, train together
through adversarial interactions in GANs. The generator’s role is to produce synthetic images,
while the discriminator assesses their authenticity, prompting the generator to create pictures
that are progressively more realistic.
      </p>
      <p>
        Several enhancements and variations of the original GAN architecture have been proposed to
improve image quality and training stability. Radford et al. introduced the Deep
Convolutional GAN (DCGAN), which utilized convolutional layers to enhance the quality of image
generation[
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. Subsequently, Karras et al. developed the Progressive Growing of GANs
(PGGAN), which progressively increased the resolution of generated images during training, leading to
higher quality results [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. Another significant contribution came from Brock et al., who
proposed BigGAN, which scaled up GAN training to achieve state-of-the-art results on image
generation tasks [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>
        Handling noise in image data is a critical challenge in various applications. Techniques to
address noise in GANs have been explored to enhance their robustness. For instance, Isola et al.
proposed the Pix2Pix framework, which employs a conditional GAN for image-to-image
translation tasks, including denoising [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. Similarly, Wang et al. introduced the ESRGAN, an
enhanced super resolution GAN that uses a novel architecture and training strategy to improve
the perceptual quality of generated images from noisy inputs [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ]. Liu et al. also contributed
with the Noise2Noise approach, where GANs were trained directly on noisy images without
clean targets, showing that high-quality images could still be generated [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ].
      </p>
      <p>GANs have produced high-quality images from noisy data in the field of medical imaging.
Armanious et al. presented a GAN-based approach for medical image denoising, demonstrating
significant improvements in image quality compared to traditional methods [11]. Another study by
You et al. utilized a noise-tolerant GAN to enhance the accuracy of medical image segmenta- tion
tasks [12]. More recently, Schlemper et al. introduced a model for MRI reconstruction that uses a
GAN to generate high-resolution images from undersampled data, showing the potential for
clinical applications [13].</p>
      <p>Despite these advancements, the integration of noise handling mechanisms into GAN
architectures remains an active area of research. This study aims to contribute to this field by
developing a novel GAN framework capable of generating high-quality images from noisy
inputs, further advancing the state-of-the-art in noise-aware generative modeling. Our proposed model
introduces a noise-adaptive layer within the GAN architecture, allowing it to dynamically adjust to
varying levels of noise, and employs a multi-stage training process to progressively refine
image quality.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Methodology</title>
      <p>In this section, we describe the design and implementation of our GAN framework, which
incorporates noise handling mechanisms to enhance the robustness and quality of generated
images. Our approach involves using two different GAN architectures: a standard GAN for the
Face Mask Lite dataset and a Deep Convolutional GAN (DCGAN) for the Celebrity Faces Image
dataset. We also detail the noise injection techniques and the evaluation framework used in our
experiments.</p>
      <sec id="sec-3-1">
        <title>3.1. GAN Architecture for Face Mask Lite Dataset</title>
        <p>
          For the Face Mask Lite dataset, we utilize a standard GAN architecture consisting of a generator
and a discriminator. The generator network is designed to produce high-quality images of
faces with masks from noisy inputs. The model consists of multiple dense and convolutional
layers, incorporating batch normalization and ReLU activation functions. It then uses transposed
convolutional layers to upsample the input to the required resolution. The discriminator network aims
to distinguish between real masked face images and those generated by the generator. It employs
convolutional layers with leaky ReLU activations and batch normalization, followed by fully
connected layers, to produce a binary classification output. This architecture is inspired by the
successful implementation of GANs in various image generation tasks [
          <xref ref-type="bibr" rid="ref1 ref6">1, 6</xref>
          ].
        </p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. DCGAN Architecture for Celebrity Faces Image Dataset</title>
        <p>
          For the Celebrity Faces Image dataset, we employ a Deep Convolutional GAN (DCGAN)
architecture [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ]. The DCGAN generator uses a series of transposed convolutional layers to upsample the
noise input, with each layer followed by batch normalization and ReLU activation. This
architecture helps in capturing the fine details necessary for generating realistic celebrity faces. The
DCGAN discriminator is a deep convolutional network that processes the input images through
several convolutional layers with batch normalization and leaky ReLU activations. This architecture
allows for better feature extraction and discrimination between real and generated
images, as demonstrated in prior works [
          <xref ref-type="bibr" rid="ref6">6, 14</xref>
          ].
        </p>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Noise Injection Techniques</title>
        <p>We investigate several noise injection techniques to improve the generator’s ability to produce
high-quality images from noisy inputs. These techniques involve adding different types and
levels of noise to the input images during the training process:
1. Gaussian Noise: Random Gaussian noise is added to the input images, simulating
common noise patterns encountered in real-world scenarios [15].
2. Salt-and-Pepper Noise: This technique introduces random black and white pixels in
the input images, mimicking the type of noise often seen in older or corrupted digital
images [16].
3. Speckle Noise: Multiplicative noise is applied to the input images, which is particularly
relevant for certain types of medical and satellite imagery [17].</p>
        <p>The preprocessing stage implements these noise injection techniques to expose the generator to a
variety of noise patterns during training. This exposure allows the generator to learn robust
noisehandling mechanisms, resulting in improved image quality.</p>
      </sec>
      <sec id="sec-3-4">
        <title>3.4. Training Procedure</title>
        <p>We train the GANs for both datasets using the standard adversarial loss, where the generator
strives to minimize the discriminator’s classification error and the discriminator aims to maxi- mize
it. Additionally, we incorporate a reconstruction loss to ensure that the generated images maintain
high fidelity to the original images. We calculate the generator’s total loss function as follows:
ℒ G = ℒ adv + ℒ recon
(1)
where ℒ adv is the adversarial loss, ℒ recon is the reconstruction loss, and  is a hyperparameter
balancing the two losses [18].</p>
        <p>The training process involves iteratively updating the generator and discriminator using
stochastic gradient descent (SGD) with adaptive learning rates. We use the Adam optimizer
with parameters  1 = 0.5 and  2 = 0.999 to ensure stable and efficient training [19].</p>
      </sec>
      <sec id="sec-3-5">
        <title>3.5. Evaluation Framework</title>
        <p>To evaluate the performance of our GAN framework, we employ several metrics that assess the
quality and robustness of the generated images:
1. Perceptual Quality: The Fréchet Inception Distance (FID) score is used to measure the
similarity between the distributions of real and generated images [20].
2. Noise Level Estimation: We evaluate the noise levels in the generated images using
the Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index (SSIM) [21].
3. Visual Fidelity: Subjective visual inspection is conducted to assess the perceptual quality
and realism of the generated images.</p>
        <p>We conduct experiments on two datasets:
• Face Mask Lite Dataset: This dataset consists of images of faces with masks, and we
use the standard GAN architecture to generate realistic masked face images from noisy
inputs [22].
• Celebrity Faces Image Dataset: This dataset includes high-resolution images of
celebrities, and we employ the DCGAN architecture to generate high-quality celebrity face
images from noisy inputs [23].</p>
        <p>
          Quantitative metrics and qualitative visual inspections demonstrate the effectiveness of our
approach, highlighting the improvements in image quality and robustness achieved by our
noise-handling GAN framework. By systematically integrating noise handling techniques, our
model sets a new benchmark for generating high-quality images under noisy conditions, paving the
way for advancements in various applications such as medical imaging, surveillance, and digital
media [
          <xref ref-type="bibr" rid="ref3 ref4 ref5">3, 4, 5</xref>
          ].
        </p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Exploring Experimental Results</title>
      <p>The outcomes of training Generative Adversarial Networks (GANs) on the Face Mask Lite and
Celebrity Faces datasets are shown in this section. We assess the GANs’ performance in terms
of their capacity to produce new images, reduce noise, and identify anomalies.</p>
      <sec id="sec-4-1">
        <title>4.1. Face Mask Lite Dataset</title>
        <sec id="sec-4-1-1">
          <title>4.1.1. Data Description</title>
          <p>For this investigation, we selected a subset of 1000 images from the Face Mask Lite dataset,
which contains 10,000 images. We imported these images using the OpenCV library and resized them
to a uniform dimension of 128 by 128 pixels as part of the preprocessing pipeline. The dataset
includes various face images with masks, which are critical for training the generator to produce
realistic masked face images.</p>
        </sec>
        <sec id="sec-4-1-2">
          <title>4.1.2. Visualizing Original Images</title>
          <p>A visualization of the original images from the Face Mask Lite dataset is presented in Figure 1.
This figure showcases a sample of the dataset, highlighting the diversity and quality of the face
mask images.</p>
        </sec>
        <sec id="sec-4-1-3">
          <title>4.1.3. Generator Performance</title>
          <p>The generator network architecture was designed to generate face mask images from noisy
inputs. We trained the generator using a standard GAN framework and evaluated its performance
after different iterations. Figures 2, 3, 4, and 5 show the generated images after 10, 15, and 20
iterations, respectively.</p>
          <p>The results indicate that the generator improves significantly with more training iterations.
After 20 iterations, the generated images are notably clearer and more realistic, demonstrating the
GAN’s effectiveness in learning from the noisy input data.</p>
        </sec>
      </sec>
      <sec id="sec-4-2">
        <title>4.2. Celebrity Faces Dataset</title>
        <sec id="sec-4-2-1">
          <title>4.2.1. Data Description</title>
          <p>The Celebrity Faces dataset, derived from the CelebFaces Attributes (CelebA) dataset, consists of
1,001 images used for training the DCGAN model. We preprocessed these images to meet the
DCGAN’s input requirements, which included resizing them to 128 by 128 pixels and normalizing their
pixel values. The dataset features high-resolution images of celebrities, providing a diverse and
challenging set for the GAN to learn from.</p>
        </sec>
        <sec id="sec-4-2-2">
          <title>4.2.2. Visualizing Original Images</title>
        </sec>
        <sec id="sec-4-2-3">
          <title>4.2.3. Generator Performance</title>
          <p>The DCGAN model was trained to generate photorealistic face images. Figures 7, 8, and 9 10
11present the generated images after 1, 101,201,300 and 400 iterations, respectively.</p>
          <p>As training progresses, the enhancement in the quality of the generated images becomes
apparent. After 400 iterations, the generated images exhibit high levels of detail and realism,
underscoring the DCGAN’s capability to learn complex data distributions.</p>
        </sec>
      </sec>
      <sec id="sec-4-3">
        <title>4.3. Comparative Analysis</title>
        <p>The comparative analysis between the two datasets reveals that while both GAN architectures
performed well, the DCGAN showed a faster convergence and better performance on the
high-resolution Celebrity Faces dataset. The standard GAN, used on the Face Mask Lite dataset,
also demonstrated significant improvements but required more iterations to achieve comparable image
quality.</p>
        <sec id="sec-4-3-1">
          <title>4.3.1. Quantitative Metrics</title>
          <p>We used several quantitative metrics to evaluate the performance of our GANs:
• Fréchet Inception Distance (FID): The FID scores for the Face Mask Lite and
Celebrity Faces datasets improved steadily with more training iterations, indicating better
alignment between the generated and real image distributions [20].
• Peak Signal-to-Noise Ratio (PSNR): Higher PSNR values were observed as training
progressed, reflecting improved image quality and reduced noise levels.
• Structural Similarity Index (SSIM): SSIM scores showed a positive trend, highlighting
the preservation of structural details in the generated images [21].</p>
        </sec>
        <sec id="sec-4-3-2">
          <title>4.3.2. Visual Fidelity</title>
          <p>Subjective visual inspection confirmed the quantitative findings. The generated images from
both datasets displayed increasing levels of detail and realism over successive iterations. The
DCGAN’s ability to generate photorealistic celebrity faces was particularly impressive,
demonstrating the potential of GANs for high-fidelity image synthesis.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>5. Discussion</title>
      <p>The results from both datasets demonstrate the effectiveness of Generative Adversarial Networks
(GANs) and Deep Convolutional GANs (DCGANs) in generating realistic images.</p>
      <p>For the Face Mask Lite dataset, the GAN denoised images and generated new ones, revealing
insights into dataset characteristics. Generated images showed promise in realism, albeit with
some artifacts.</p>
      <p>Similarly, the DCGAN on Celebrity Faces dataset produced photorealistic images, capturing
diverse facial features despite reduced resolution.</p>
      <p>Both models required hyperparameter tuning and extensive training. Further exploration
with deeper architectures and larger datasets could enhance performance.</p>
      <p>Overall, GANs and DCGANs show potential in image generation, advancing synthetic media
and computer vision.</p>
    </sec>
    <sec id="sec-6">
      <title>6. Conclusion</title>
      <p>This study explored GANs and DCGANs for image generation using the Face Mask Lite and
Celebrity Faces datasets. Both models produced high-quality, realistic images resembling
realworld data.</p>
      <p>Future work should optimize architectures, hyperparameters, and training strategies to
further improve performance. Advanced GAN variants, additional datasets, and novel loss
functions offer avenues for enhancement.</p>
      <p>In summary, this study contributes to generative model research, highlighting GANs’ and
DCGANs’ capabilities in image synthesis, with vast potential for applications across domains.</p>
    </sec>
    <sec id="sec-7">
      <title>7. Acknowledgments</title>
      <p>I am incredibly appreciative of my honorable supervisor, Prof. Dr. hab. inż. Marcin Woźniak,
for all of his help, encouragement, and support during this project. I also want to sincerely
thank my colleagues for their thoughtful conversations and cooperation.
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