Heekyung Yang

Prof. Dr. Heekyung Yang

Sangmyung University, Seoul, Republic of Korea
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 January 2024 in Mathematics
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JKJunho Kim
Junho Kim
Heekyung YangHeekyung Yang
Heekyung Yang
KMKyungha Min
Kyungha Min
We propose a framework that synthesizes artistic landscape sketches using a diffusion model-based approach. Furthermore, we suggest a three-channel perspective map (3CPM) that mimics the artistic skill used by real artists. We employ Stable Diffusion, which leads us to use ControlNet to process 3CPM in Stable Diffusion. Additionally, we adopt the Low Rank Adaptation (LoRA) method to fine-tune our framework, thereby enhancing the quality of sketch and resolving the color-remaining problem, which is a frequently observed artifact in the sketch images using diffusion models. We implement a bimodal sketch generation interface: text to sketch and image to sketch. In producing a sketch, a guide token is used so that our method synthesizes an artistic sketch in both cases. Finally, we evaluate our framework using quantitative and quantitative schemes. Various sketch images synthesized by our framework demonstrate the excellence of our study.

14 December 2019 in Sensors
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Journal Article
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Heekyung YangHeekyung Yang
Heekyung Yang
JHJongdae Han
Jongdae Han
KMKyungha Min
Kyungha Min
Visual stimuli from photographs and artworks raise corresponding emotional responses. It is a long process to prove whether the emotions that arise from photographs and artworks are different or not. We answer this question by employing electroencephalogram (EEG)-based biosignals and a deep convolutional neural network (CNN)-based emotion recognition model. We employ Russell’s emotion model, which matches emotion keywords such as happy, calm or sad to a coordinate system whose axes are valence and arousal, respectively. We collect photographs and artwork images that match the emotion keywords and build eighteen one-minute video clips for nine emotion keywords for photographs and artwork. We hired forty subjects and executed tests about the emotional responses from the video clips. From the t-test on the results, we concluded that the valence shows difference, while the arousal does not.

25 January 2024 in Electronics
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HYHyemin Yang
Hyemin Yang
Heekyung YangHeekyung Yang
Heekyung Yang
KMKyungha Min
Kyungha Min
We present a diffusion model-based approach that applies the artistic style of an artist or an art movement to a portrait photograph. Learning the style from the artworks of an artist or an art movement requires a training dataset composed of a lot of samples. We resolve this limitation by combining Contrastive Language Image Pretraining (CLIP) encoder and diffusion model, since the CLIP encoder extracts the features from an input portrait in a very effective way. Our framework includes three independent CLIP encoders that extract the text features, color features and Canny edge features from an input portrait, respectively. These features are incorporated to the style information extracted through a diffusion model to complete the stylization on an input portrait. The diffusion model extracts the style information from the sample images in the training dataset using an image encoder. The denoising steps in the diffusion model applies the style information from the training dataset to the CLIP-based features from an input portrait. Finally, our framework produces an artistic portrait that presents both the identity of the input portrait and the artistic style from the training dataset. The most important contribution of our framework is that our framework requires less than a hundred sample images for an artistic style. Therefore, our framework can successfully extract styles from an artist who has drawn less than a hundred artworks. We sample three artists and three art movements and apply these styles to the portraits of various identities and produce visually pleasing results. We evaluate our results using various metrics, including Frechet Inception Distance (FID), ArtFID and Language-Image Quality Evaluator (LIQE) to prove the excellence of our results.

13 August 2020 in Sensors
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Heekyung YangHeekyung Yang
Heekyung Yang
JHJongdae Han
Jongdae Han
KMKyungha Min
Kyungha Min
Visual contents such as movies and animation evoke various human emotions. We examine an argument that the emotion from the visual contents may vary according to the contrast control of the scenes contained in the contents. We sample three emotions including positive, neutral and negative to prove our argument. We also sample several scenes of these emotions from visual contents and control the contrast of the scenes. We manipulate the contrast of the scenes and measure the change of valence and arousal from human participants who watch the contents using a deep emotion recognition module based on electroencephalography (EEG) signals. As a result, we conclude that the enhancement of contrast induces the increase of valence, while the reduction of contrast induces the decrease. Meanwhile, the contrast control affects arousal on a very minute scale.

12 August 2020 in IEEE Access
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Journal Article
Open access
CPCheolseong Park
Cheolseong Park
Heekyung YangHeekyung Yang
Heekyung Yang
KMKyungha Min
Kyungha Min
We present a framework that generates a 2D Lego-compatible puzzle layout of greater than thousands pieces of bricks using a reinforcement learning technique. Many existing 2D legorization strategies have limitations in producing a Lego layout, which is composed of more than thousands of pieces. We attack this problem by employing a reinforcement learning technique, which accelerates the progress of various game strategies. We represent the legorization process as a game tree search problem, where each leaf node of the tree corresponds to a Lego layout. The goal of legorization is to find an optimal Lego layout that achieves maximum reward. To efficiently find a leaf node for the maximum reward layout, we reduce the search space using a dueling deep Q-Network (DQN), which is a widely used reinforcement learning model. Our framework is composed of a learning stage and a legorization stage. In the learning stage, we design a dueling DQN model and train this model using three heuristics for legorization strategies. In the legorization stage, we efficiently generate a large-scaled 2D Lego-compatible puzzle layout by reducing the search space using the trained dueling DQN. This approach enables us to produce a puzzle layout of more than a thousand of pieces, which has not been feasible for existing legorization schemes.

17 October 2021 in Electronics
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MJMinji Jung
Minji Jung
Heekyung YangHeekyung Yang
Heekyung Yang
KMKyungha Min
Kyungha Min
The advancement and popularity of computer games make game scene analysis one of the most interesting research topics in the computer vision society. Among the various computer vision techniques, we employ object detection algorithms for the analysis, since they can both recognize and localize objects in a scene. However, applying the existing object detection algorithms for analyzing game scenes does not guarantee a desired performance, since the algorithms are trained using datasets collected from the real world. In order to achieve a desired performance for analyzing game scenes, we built a dataset by collecting game scenes and retrained the object detection algorithms pre-trained with the datasets from the real world. We selected five object detection algorithms, namely YOLOv3, Faster R-CNN, SSD, FPN and EfficientDet, and eight games from various game genres including first-person shooting, role-playing, sports, and driving. PascalVOC and MS COCO were employed for the pre-training of the object detection algorithms. We proved the improvement in the performance that comes from our strategy in two aspects: recognition and localization. The improvement in recognition performance was measured using mean average precision (mAP) and the improvement in localization using intersection over union (IoU).