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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>StyleGAN-Canvas: Augmenting StyleGAN3 for Real-Time Human-AI Co-Creation</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Shuoyang Zheng</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Creative Computing Institute, University of the Arts London</institution>
          ,
          <addr-line>45-65 Peckham Rd, London</addr-line>
          ,
          <country country="UK">UK</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Motivated by the mixed initiative generative AI interfaces (MIGAI), we propose bridging the gap between StyleGAN3 and human-AI co-creative patterns by augmenting the latent variable model with the ability of image-conditional generation. We modify the existing generator architecture in StyleGAN3, enabling it to use high-level visual ideas to guide the human-AI co-creation. The resulting model, StyleGAN-Canvas, can solve various image-to-image translation tasks while maintaining the internal behaviour of StyleGAN3. We deploy our models to a real-time graphic interface and conduct qualitative human opinion studies. We use the MIGAI framework to frame our findings and present a preliminary evaluation of our models' usability in a generic co-creative context.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;generative adversarial networks</kwd>
        <kwd>human-AI co-creation</kwd>
        <kwd>creativity support tools</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>
        erative neural networks, StyleGAN models have been
found to be widely used as creativity support tools,
creating unconventional visual aesthetics [
        <xref ref-type="bibr" rid="ref5 ref6 ref7">5, 6, 7</xref>
        ] and novel
human-AI co-creative experiences [8, 9, 10, 11]. This
motivates research on human-AI co-creative applications,
ofering insight into interaction possibilities between
human creators and AI enabled by GANs [12].
      </p>
      <p>
        Muller et al. [13] adapt notations introduced by Spoto
FCiagnuvraes 1m: oAdeplrotrtaontyslpaetiinngteprafapceer ecnarcdaplasuyolauttinigntao SfatycleesG.TAhNe- and Oleynik [14], presenting mixed initiative generative
user adjusts layouts while the model provides synchronous AI interfaces (MIGAI), an analytical framework with 11
generation based on visual similarity. A screen recording is vocabularies of actions to describe a human-AI
interacavailable at: https://youtu.be/9AsfsT8uXGY tion process. These actions are analysed into sequences
to form generic human-AI co-creative patterns.
However, Grabe et al. [15] identify a gap between the MIGAI
1. Introduction framework and latent variable models such as GANs.
This is partially due to latent variable models’ deficiency
Generative adversarial networks (GANs) [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] have re- of ability in interpreting visual design concepts such as
cently been rapidly developed and have become a pow- sketches and semantic labels [16], leading to the left-out
erful tool for creating high-quality digital artefacts. In of the action ideate [15], which describes using high-level
the case of images, modern approaches to improving concepts to guide or shape the generation [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. Therefore,
model quality have successfully brought the generated Grabe et al. [15] suggested tailoring the MIGAI
frameoutcomes from coarse low-resolution interpretations to work to fit co-creative GAN applications.
realistic portraits with high diversity [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] and visual fi- Motivated by the gap between GANs and human-AI
delity [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Notably, introducing continuous convolution co-creative patterns, we suggest an alternative approach
in StyleGAN3 (alias-free GAN) [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] has enabled the gener- to bridge the latent variable model, StyleGAN3, to the
ative network to perform equally well regardless of pixel co-creative framework by modifying the model’s
technicoordinates, paving the way for more flexible human-AI cal functioning. Specifically, by augmenting StyleGAN3
interaction. Closely following the advances in deep gen- with image-conditional generation ability, we enable it
to transform visual ideas into generation. This enables a
Joint Proceedings of the ACM IUI Workshops 2023, March 2023, Sydney, tightly-coupled human-AI interaction process that
emAustralia phasises using high-level visual concepts to guide the
* Corresponding author. artefact and fulfil the action ideate [13], aligning with the
$ hj.ztthpesn:/g/a0l3a2s0k2a1w1@intaerrt.sc.ca/c.(uSk.Z(Sh.eZnhg)eng) co-creative patterns mentioned in the MIGAI framework.
0000-0002-5483-6028 (S. Zheng) We limit our study to StyleGAN3 because its
introduc© 2023 Copyright for this paper by its authors. Use permitted under Creative Commons License tion of continuous convolution facilitates more flexible
CPWrEooUrckReshdoinpgs IhStpN:/c1e6u1r3-w-0s.o7r3g ACttEribUutRion W4.0oInrtekrnsahtioonpal (PCCroBYce4.0e).dings (CEUR-WS.org)
human inputs, which is a crucial feature required by our each comprising convolutions controlled by the
intermeapproach. diate latent code , non-linearities, and upsampling, and
      </p>
      <p>
        Therefore, the primary aim of this research is to aug- eventually produces the output image  = (0; ).
ment StyleGAN3 with image-conditional generation abil- Its high-level style control is achieved by adaptive
inity for a co-creative context. To achieve this, we adapt the stance normalisation (AdaIN) [21], an approach to
ampliexisting model architecture in StyleGAN3, which takes fying specific channels of feature maps on a per-sample
a latent vector and a class label as the model’s input [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ], basis. In practice, a learned afine transform is applied to
and propose an encoder network to extract features from the intermediate latent space  to obtain style codes ,
the conditional image. We also adapt the architecture which are then used as scalar components to modulate
previously applied to various image-to-image translation the corresponding feature maps before each convolution
models [17, 18, 19] to connect the proposed encoder and layer. This architecture was then revised in StyleGAN2
StyleGAN3’s generator. The modified model, StyleGAN- [22] by replacing instance normalisation with feature
Canvas, takes a latent vector and an accompanying image map demodulation and inherited by StyleGAN3.
as inputs to guide the generation. We show results from In a later work, the continuous convolution approach
our models trained for various image-to-image transla- [23] implemented in StyleGAN3 (alias-free GAN) [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] has
tion tasks while maintaining the internal behaviours of dramatically changed the internal representations in the
StyleGAN3, providing more flexible and intuitive control synthesis network . Signals in  are operated in the
to ideate the co-creation. continuous domain rather than the discrete domain to
      </p>
      <p>To evaluate our model in a generic co-creative context, make the network equivariant, which means any
operawe build a graphic interface to facilitate the real-time tion  in the network is equivariant to a spatial
transforinteraction between users and the model. We conduct mation  ( ∘  =  ∘ ). This eliminates positional
referqualitative human opinion studies, identify potential co- ences; therefore, the model can be trained on unaligned
creative patterns using the MIGAI analytical framework, data, and the "texture sticking" behaviour in standard
and present an exploratory human subject study on our GAN models is removed.
model. By aligning StyleGAN-Canvas with the actions Moreover, the input of the synthesis network of
Styleset in MIGAI, we hope to bring its capability into the GAN3 uses a spatial map 0 defined by Fourier features
discussion of co-creative design processes, and provide [24] to precisely model the translation and rotation. The
a preliminary insight into the unexplored interaction spatial map 0 is sampled from uniformly distributed
frepossibilities enabled by StyleGAN. quencies, fixed after initialisation, and spatially infinite</p>
      <p>
        The rest of the paper is structured as follows. We sum- [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. Its translation and rotation parameters are calculated
marise related works on StyleGAN, image-conditional by a learned afine layer based on intermediate latent
generation, and the co-creative pattern in Section 2. Then, space  . The spatial map 0 acts as a coordinate map
we present our modification to the model’s architecture that allows later layers to grab on and therefore defines
in Section 3. We conduct experiments on our models the global transformations in the synthesis network [25].
and showcase the results and applications in Section 4.
      </p>
      <p>Next, we evaluate the model in a co-creative context in 2.2. Image-Conditional Generation
Section 5. Section 6 highlights limitations and future
studies.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Related Works</title>
      <sec id="sec-2-1">
        <title>2.1. Alias-Free GAN</title>
        <sec id="sec-2-1-1">
          <title>Our model architecture is extended from StyleGAN3</title>
          <p>(Alias-Free GAN). This section summarises the
background of StyleGAN and reviews the continuous
convolution approach introduced by StyleGAN3 that enables
the translation and rotation equivariant feature.</p>
          <p>StyleGAN [20] is a style-based generator with a
regularised latent space ofering high-level style control over
image generation. The StyleGAN generator comprises
a mapping network  that transforms the initial latent
code  to intermediate latent code  ∼  , and a
synthesis network  with a sequence of  synthesis blocks,
Methods for image-conditional generation aim to
generate a corresponding image given an image from the
source domain, depicting objects or scenes in diferent
styles or conditions. Current solutions to this are usually
categorised under two approaches. The first approach
uses a linear encoder-decoder architecture [26], in which
the input image is encoded to a vector to match the target
domain, and then decoded into an output image. This
method was later extended to a generic framework for
various tasks, such as sketches and layout to image, facial
frontalisation, inpainting, and super-resolution [27].</p>
          <p>The second direction uses conditional GANs [17]
with U-net architectures [28]. It uses a similar
encoderdecoder setting, but instead of encoding the input image
into a vector, it uses the residual feature maps from the
encoder as spatial information and propagates them to
the decoder through skip connections [29]. The
propagated features are concatenated with the outputs from</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Extending StyleGAN to</title>
    </sec>
    <sec id="sec-4">
      <title>Image-conditional Generation</title>
      <sec id="sec-4-1">
        <title>The objective of our approach is to allow StyleGAN3 to</title>
        <p>use images as conditions to guide the generation. This
section will discuss our modification to the current
StyleGAN3 architecture to address this objective.</p>
        <p>As mentioned in Section 2.1, current StyleGAN3
models learn a mapping from a random noise vector  to an
output image  = (). The modification aims to
extend the input from a vector  to a conditional image
 combined with , and generate  that is close to
the corresponding ground truth . To do this, we first
need a feature extraction encoder  that extracts features
from , then adapts the generator  to produce outputs
based on the extracted features and the input vector ,
i.e.  = ((), ). Besides, the training objective
should push the generation closer to the corresponding
image .
corresponding decoder layers. This method aims to
provide the generator with a mechanism to circumvent the
bottleneck layer and allow spatial information to be
shuttled from the encoder to the decoder [28]. Therefore, it
introduces a strong locality bias [26] into the generation,
which means each pixel in the output has a positional
reference to the input, and the general image structure
is preserved during translation. This method has been
extended for various tasks such as line-conditioned
generation [19], layout-to-image synthesis [30], and semantic
region-adaptive synthesis [31].</p>
        <sec id="sec-4-1-1">
          <title>2.3. Human-AI Co-Creative Pattern</title>
        </sec>
      </sec>
      <sec id="sec-4-2">
        <title>Mixed Initiative Generative AI Interfaces (MIGAI) [13]</title>
        <p>describe modes of interaction in which both human and
generative AI is engaged in a creative process. It aims
to frame subprocesses in a creative flow by an action
set with 11 vocabularies. A generic co-creative pattern
is identified using the MIGAI framework, in which the
AI system first learns a target domain, then the human
ideates a design concept to guide the artefact; subse- 3.1. Feature Extraction Encoder
quently, the human and AI system take turns to eval- 3.1.1. Adapted Residual Network
uate and adjust, eventually produce the outcome [15].</p>
        <p>Our study focuses on ideating, a process of conceptual- The feature extraction encoder  employs an adapted
ising design solutions to high-level abstractions. Later ResNet [29] architecture as the encoder backbone, which
exploratory study emphasising the potential of enhanc- has been previously used for feature maps extraction in
ing the creative process through human-AI collaborative image-to-image translation works [27]. As shown in
Figideation [16]. Methods for this have been advanced in di- ure 2 (left), the encoder network downsamples feature
verse fields of application: co-creative game content [ 32], maps to (/26, /26), where  and  denote the width
collaborative text editing [33], and text-guided image and height of the input image. In addition, as StyleGAN
generation [34]. uses mixed-precision to speed up training and inferences</p>
        <sec id="sec-4-2-1">
          <title>3.3. Loss Functions</title>
          <p>Previous works in StyleGAN encoder [27] have
highlighted that replacing select layers of the extended latent
space  + by computed latent codes can facilitate
multimodal synthesis. And the extended latent space  + can
be roughly divided into coarse, medium, and fine layers,
corresponding to diferent levels of detail and editability
[36]. This motivates us to add a conditional mapping
network as the epilogue layer of our residual feature encoder,
which uses the same mapping network architecture in
StyleGAN, but takes a flattened 512 vector sampled from
the encoder’s bottleneck and produces a replacement
latent space  + ′. And  + ′ is then concatenated
with a portion of the latent space  + produced from
the original mapping network. This aims to facilitate
multi-modal generation.
[24], we utilise similar techniques and reduce the pre- U-Net and its variants has demonstrated that a simplified
cision to FP16 for the rfist five residual blocks in the structure with fewer feature fusions can achieve
reasonencoder. Consequently, it requires pre-normalisation and able results [37, 38]. Therefore, we reduce the number of
an extra clamping layer that clamps the output of the feature fusions and limit connections to only the first 
convolutional layers to ± 29 [35]. layers. In practice, skip connections in these five models
each connect layer  −  of the encoder to layer , where
3.1.2. Conditional Mapping Network  is the total number of layers in the encoder, and  is
limited to  ∈ (0, 5]. The experiment in Section ?? will
show that  = 5 is the best configuration that leads
to more stable training and eficient generation. This
reduction in the network maintains unification of the
network’s internal behaviour, while taking advantage of
the eficiency of U-shaped structural models.</p>
        </sec>
      </sec>
      <sec id="sec-4-3">
        <title>Standard StyleGAN loss function consists of the standard</title>
        <p>GAN loss function (i.e., logistic loss) and regularisation
terms (i.e., 1). We incorporate the training objectives in
StyleGAN with pixel-wise distance and perceptual loss
that have been used in conditional GANs.</p>
        <p>
          The model is trained using diferent combinations of
objectives at two diferent training phases. The first phase
starts from zero to the first 300k images, and this is also
3.2. Adapting Generator the phase where the training images are blurred with
a Gaussian filter to prevent early collapses [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ]. During
As mentioned in Section 2.1, the StyleGAN3 generator this phase, the pixel-wise loss 2 distance between input
consists of a mapping network and a synthesis network, images  and target images , logistic loss  and
our modification aims to connect its synthesis network regularization terms  as follows:
to extracted information from the feature extraction
encoder. 2(, ) = E,,[‖ − ((), )‖2] (1)
        </p>
        <p>We start by modifying the input layer in its synthesis
network. The original network utilises a fixed-size spatial
map 0 defined by Fourier features [ 24] as its input to  (, , ) = E[()] (2)
model translation and rotation parameters. However, the +E,[(1 − (((), )))]
entire input layer is left out, and we use feature maps
from the last layer of the encoder directly as the synthesis
network’s input. This lets the translation and rotation (,  ) = E,[‖()− ¯‖2 +‖ ()− ¯‖2] (3)
parameters be inherited from the spatial feature maps.</p>
        <p>
          Next, connections between the feature encoder aim where  and  denote the generator and the
discriminato provide precise structural information about input tor,  denotes the feature encoder, and  denotes the
images. A U-net [28] architecture is well-suited for prop- mapping network in the generator. Then, the training
agating high-level details from the encoder to the decoder loss ℎ1 is defined as:
[26]. However, as mentioned in Section 2.1, experiments ℎ1(, , ) =  12(, )
on StyleGAN3 have demonstrated that high-level feature (4)
maps in the synthesis network encode information in + (, , ) + (,  )
continuous domains instead of discrete domains [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ], re- The second phase starts after the training reaches 300k
lying on skip connections to propagates discrete features images. We add a perceptual loss   utilising a
prefrom the encoder may deviate from StyleGAN3’s inter- trained VGG19 [39] network, which has been used in
nal generation behaviour. To tackle this, we first move the training of previous conditional GANs and has led to
the concatenation node from the end of each synthesis more finer details in the resulting images [ 18], defined
block to the point before the filtered non-linearities layer, as follow:
shown in Figure 2 (right). We also remove the padding
layers in each synthesis block to ensure the dimension  (, ) = E,,[‖ ()− (5)
matches the skip connections. Additionally, research on
 (((), ))‖2]
        </p>
        <p>Then, the phase 2 loss is then calculated as follows:
ℎ2(, , ) =  12(, ) +  2 (, )
+ (, , ) + (,  )</p>
        <p>(6)
where  denotes the pre-trained VGG19 feature extractor.
 1 and  2 are constant numbers used to weigh the loss
parameters, which vary across diferent training data and
configurations.</p>
        <p>Results. Figure 3 (left) shows the results of the ablation
test for the  = 5 to  = 2 models trained on 1680k
samples. The rest of the two models ( = 1 and  =
0) are unable to converge to sensible results after 800k
samples and were therefore aborted. The results show
notable improvements when increasing the number of
skip connections, especially in preserving details such as
background, hands, unique make-up and even the details
in hairs. Therefore,  = 5 is decided as the final setting.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>4. Experiments and Applications</title>
      <sec id="sec-5-1">
        <title>4.2. Conditional Image Synthesis and</title>
      </sec>
      <sec id="sec-5-2">
        <title>Editing</title>
        <p>In the following Section 4.1, we analyse the efectiveness
of the U-net proposed in Section 3.2 by a set of ablation
studies. Next, in Section 4.2, we demonstrate the training
process of our model for several image-to-image
translation tasks with diferent datasets and showcase their
results. We also experiment with scaling the model to
larger canvases in Section 4.3. Finally, we build a graphic
interface that implements our models with a set of
transformation filters in Section 4.4.</p>
        <p>In addition, the canny edges model provides an
alternative approach to local editing. Modifying edges in the
condition image allows the model to alter semantical ele- absolute positional references [44], we hypothesised that
ments in the generation. Illustrated in Figure 4 (bottom), our modified architecture induced an extendable
generathe modified conditions can be obtained by combining tion canvas that can be enlarged after trained on a fixed
and adapting existing conditions from other images. For resolution, without additional training required.
Thereexample, in Figure 8, we superimposed edges processed fore, we enlarge the input resolution to test the model’s
from other images to the original edges to add hair fringe, ability on a larger canvas.
glasses and smile; we painted on the original edges to The model for landscape photo generation was trained
modify eyes and add sunglasses. on the dataset with 512 × 512 resolution, taking inputs
with 256× 256 resolution. To enlarge the generation
can4.3. Large Canvas vas, we doubled and tripled the width of inputs,
expanding their resolution to 1024 × 256 and 768 × 256. Then,
As mentioned in Section 3.2, the padding layers in the the expanded inputs were taken directly into the
genersynthesis network are removed, and the entire generator ator and convolved by each convolutional layer.
Theredoes not have unintentional positional references with fore, the expected output resolutions are 2048 × 512 and
1536 × 512. Additional training is not required during from 10 to 32 ( ⃗ ∈ 32) to confront larger numbers of
the experiment. channels in StyleGAN3-R.</p>
        <p>Figure 9 shows the resulting generations. While
the outputs are expanded up to four times larger than Interface design. Figure 10 shows a screenshot of the
the original canvas, the generation quality remains un- deployed system. The interface allows inputs from a
webchanged. This ensures that the input canvas can be flex- cam or locally selected image files (top left). The interface
ibly expanded when the models are implemented into allows users to pause, resume generation, and switch the
user interfaces. input between the webcam and local files. Users can
insert transformation filters into certain groups in certain
4.4. User Interface layers. The list on the bottom left side presents layers
available for network bending operations. Once a specific
Implementation. The deblurring models were de- layer is selected, the system shows current clusters of
ployed to a graphic user interface. The models were feature maps in the layer. Users can regenerate clusters
running on a cloud server. We used Flask and Socke- according to feature maps from the current frame. Then,
tIO for bi-directional communications between the web users activate the ‘route’ button to apply transformation
client and the server. The generation runs in real-time at filters to the cluster. The system provides basic
transforroughly ten frames per second on an NVIDIA RTX A4000 mation filters, including erosion and dilation, multiply,
GPU. The code for our implementation is available at translations, rotation, and scale.
https://github.com/jasper-zheng/realtime-flask-model.</p>
        <p>Combining network bending. In addition to the
baseline model, the generation system is implemented
with network bending [45], an approach to alter a trained
model’s computational graph by inserting transformation
iflters between diferent convolutional layers, allowing
the model to generate novel samples that are diverse from
the training data [46]. We used the clustering algorithm
presented by Broad et al. [45] to group spatially similar
feature maps in selected layers and allow the
transformation filters to be inserted into specific groups. We
trained softmax feature extraction CNNs for each layer
and clustered each flatten layer by the k-means algorithm.</p>
        <p>However, diferent from the implementation in Broad et
al.’s work, we increase the length of the flatten vector</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>5. Human Subjects Study and</title>
    </sec>
    <sec id="sec-7">
      <title>Evaluation</title>
      <sec id="sec-7-1">
        <title>This section presents a human subjects study to evaluate</title>
        <p>our models in a human-AI co-creation context. The study
uses a thematic analysis approach to identify potential
co-creative patterns defined by the MIGAI framework
[13] that underlies the interaction.</p>
        <sec id="sec-7-1-1">
          <title>5.1. Methodology</title>
          <p>In the user study, we asked six participants to use the Figure 11: Examples of works created by participants
generation interface described in Section 4.4. For the
webcam inputs, coloured paper cards and scissors were
available to the participants. Participants were asked
to arrange and layout paper cards in front of a webcam We used the MIGAI analytic framework [13] to frame the
pointing to a paper canvas, aiming to control the gen- human-AI co-creative patterns.
eration until it reached something they liked. Besides,
the transformation filters were also available to fine-tune 5.2.1. Learn
the creation further. Models used in Section 4.2 are
available to the participants, including the deblurring model The action learn in the MIGAI framework describes the
and the edge-to-face model trained on Flickr-Faces-HQ AI model using training data to construct its knowledge,
(FFHQ) [20], the deblurring model trained on Landscapes usually involving the choice of datasets, model
archiHigh-Quality (LHQ) [43]. tectures, and training configurations. Most participants</p>
          <p>The experiment followed the qualitative research pro- used the model trained on the landscape dataset in the
cedure described by Adams et al. Adams et al. [47]. Six end. When questioned on the reason for this decision,
participants were divided into two groups of three. We they suggested the surprising, unexpected results
proconducted the study on the first group and ran an analy- duced by the landscape model are more likely to be
acsis to emphasise issues raised by the participants based cepted by their visual aesthetic. Although both models
on their frequency and fundamentality, leading to tenta- can create unrealistic imagery, distortion and oddities on
tive findings. Then, the interview questions are revised human faces may easily lead to uncanny feelings and,
for the second group to probe and grow these findings. more importantly, negative ethical issues such as bias
The study was divided into two parts, each lasting 15 and ofences. Therefore, the choice of training data is
minutes. The first part asked participants to familiarise critical for co-creation.
the interface and explore the system components. The
second part asked the participant to create a work they 5.2.2. Ideate
liked. Observation is conducted while participants
interact with the framework, and a 5-minute semi-structured
interview with open-ended questions follows each part
of the experiment.</p>
          <p>Participants were questioned on their attitudes
regarding this form of interaction, the creation process, their
generation outcomes, and the diferences in their
perceptions of diferent models. We loosely followed the
interview template during the interviews while ensuring
these four topics were covered.</p>
          <p>Figure 11 shows some examples of works created by
the participants.</p>
          <p>The action ideate describes the process of using
highlevel concepts to guide the generation. We collected
comments aggregated around this process. Some
positive comments indicate that creating shapes using paper
cards is an intuitive generation process. Whereas some
negative comments suggest that the lack of controls in
details (e.g., textures in the landscapes, details of the
facial elements) leads to confusion and complaint. Most
participants pointed out that they would use this form of
generation as inspiration, giving them a high-level sketch
developed from their ideated concept. Alternatively, they
may treat it as a playful experience or simply in pursuit of
an abstract visual efect. However, if the generation aims
to create a serious piece of work, they would eventually
switch to more stable methods with lower-level control
to refine the work, such as Photoshop or CAD software.</p>
          <p>This is because, in this case, they want to be manually in
charge of finer details such as lighting and textures.</p>
        </sec>
      </sec>
      <sec id="sec-7-2">
        <title>In this section, we use the thematic analysis [48] method to aggregate comments collected from the interview, aiming to identify critical factors influencing the interaction.</title>
        <sec id="sec-7-2-1">
          <title>5.2. Analysis</title>
          <p>5.2.3. Adapt
5.2.4. IterativeLoop
The action adapt describes adjusting existing artefacts. The MIGAI framework uses IterativeLoop to describe
huDuring the study, we observed that participants primar- mans reflectively learning from the co-creative process.
ily focused on exploring the outcome from the compu- We observed that some participants might memorise
usetational agent by arbitrarily arranging the paper cards. ful patterns of shapes and colours that may trigger
satisWhen they reach a layout that triggers interesting results, factory results, and later use the paper card to reproduce
they iteratively adjust the arrangement until achieving these patterns. Some participants describe this process
a satisfying result. Some participants tried to tackle the as a way to learn the preferences of the AI model to steer
lack of control by utilising other pre-processing or post- the co-creation through reflection.
processing processes. Figure 12 illustrates an example
of an action that attempts to fix the oddity by slightly 5.3. Discussion
warping the intermediate image in other image editing
software. Figure 13 illustrates a sequence of editing per- The motivation of this paper was to augment style-based
formed on intermediate condition images to intentionally GAN models into a co-creative context. By extending the
create unrealistic and novel outcomes. The edges were StyleGAN model to image-conditional generation, these
edited and assembled before the generation using Photo- models allow human agents to ideate a high-level
conshop, and then uploaded to the interface as inputs. The cept of the artefacts, like blurred arrangement or edges.
user evaluated the current outcome, and then iteratively The flexibility of input and the semantically meaningful
ifne-tuned the edges according to their preferences. control are critical features for efective co-creative
experiences. Meanwhile, to create a sense of a "cooperated
partner", the computational agent needs to maintain a
certain level of unpredictability, and AI’s contribution
needs to partly influence the human agents’ decision [ 49].</p>
          <p>Therefore, the co-creative process balances machine
autonomy and human creativity. Our current results are
good indications that human agents act as a director
who steers the model by organising and reusing learned
knowledge in the computational agent. While further
studies on the model architecture may improve the
generation quality, the current results in this research show
that bridging StyleGAN3 to the co-creative context is
possible. Furthermore, it could be employed for novel and
unique co-creative experiences. For example, Figure 14
shows an interactive installation with webcam inputs
that produce 704 × 1280 images in real-time.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-8">
      <title>6. Conclusion</title>
      <sec id="sec-8-1">
        <title>In this work, we augmented StyleGAN3 with the ability</title>
        <p>of image-conditional generation, enabling it to turn
highlevel visual ideas into generation. This augmentation
aligned latent variable models with the co-creative
patterns mentioned in the MIGAI framework and brought
StyleGAN3 into a co-creative context. We adapted the
existing model architecture and proposed an encoder
network to extract information from the conditional image.
We demonstrated the modified architecture,
StyleGANCanvas, on various image-to-image translation tasks with
diferent datasets. In addition, we deployed our models to
a graphic interface to facilitate the real-time interaction
between users and the model. To evaluate our models
in a co-creative context, we conducted qualitative
human opinion studies and identified potential co-creative
patterns using the MIGAI analytic framework.</p>
        <sec id="sec-8-1-1">
          <title>6.1. Limitation and Future Works</title>
          <p>An overall criticism was the need for more interpretable
control in the system. While the input image acts as
a blueprint for the generation, the user also needs
precise control over the details when using the model as a
creative tool. This leads us to rethink the design of the
intermediate representation. Our framework currently
only implements deblurring models for the experiment,
however, it might be more useful to use intermediate
representations that encode more detailed information
(e.g., boundary maps or edges) like the interactive demos
in pix2pixHD.</p>
          <p>Besides, the proposed architecture can also be
improved in technical aspects. Our approach proposes an
alternative for extending StyleGAN models to
imageconditional generation. Although it has demonstrated
its potential in solving several image-to-image
translation tasks, the detailed architecture still needs further
investigation and refinement to improve the generation
quality. Our model architecture utilises the equivariant
generator in StyleGAN3. However, our feature
extractor still needs to be rotation equivariant. Therefore, the
generation may sufer when the rotation is not encoder.
Figure 15 show an example of failure where the encoder
does not preserve the rotation. It would be beneficial to
make the feature encoder equivariant in future work.</p>
        </sec>
      </sec>
      <sec id="sec-8-2">
        <title>Potential negative societal impacts of images produced</title>
        <p>by GAN [50] were considered throughout the project.
The models trained on the FFHQ dataset are for purely
academic purposes, and its interactive prototype will not
be publicly distributed by any means. Model trainings
used approximately 300 hours of computation on A100
SXM4 80GB (TDP of 400W). Total emissions are estimated
to be 25.92kg 2, as calculated by MachineLearning
Impact calculator [51]. Paper cards in the experiments
were limitedly allocated to participants, reused during
and after the experiments.</p>
      </sec>
    </sec>
    <sec id="sec-9">
      <title>Acknowledgments</title>
      <sec id="sec-9-1">
        <title>This research was carried out under the supervision of Prof. Mick Grierson. I sincerely appreciate and treasure feedbacks and comments from him.</title>
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