Sketch-Guided Motion Diffusion for Stylized Cinemagraph Synthesis

Designing stylized cinemagraphs is challenging due to the difficulty in customizing complex and expressive flow motions. To achieve intuitive and detailed control of the generated cinemagraphs, freehand sketches can provide a better solution to convey personalized design requirements than only text inputs. In this paper, we propose Sketch2Cinemagraph, a sketch-guided framework that enables the conditional generation of stylized cinemagraphs from freehand sketches. Sketch2Cinemagraph adopts text prompts for initial content generation and provides hand-drawn sketch controls for both spatial and motion cues. The latent diffusion model is adopted to generate target stylized landscape images along with realistic versions. Then, a pre-trained object detection model is utilized to segment and obtain masks for the flow regions. We proposed a novel latent motion diffusion model to estimate the motion field in the fluid regions of the generated landscape images. The input motion sketches serve as the conditions to control the generated vector fields in the masked fluid regions with the prompt. To synthesize the cinemagraph frames, the pixels within fluid regions are subsequently warped to the target locations for each timestep using a frame generator. The results verified that Sketch2Cinemagraph can generate high-fidelity and aesthetically appealing stylized cinemagraphs with continuous temporal flow from intuitive sketch inputs. We showcase the advantages of Sketch2Cinemagraph through quantitative comparisons against the state-of-the-art generation approaches.

A Semi-automatic Oriental Ink Painting Framework for Robotic Drawing from 3D Models

Creating visually pleasing stylized ink paintings from 3D models is a challenge in robotic manipulation. We propose a semi-automatic framework that can extract expressive strokes from 3D models and draw them in oriental ink painting styles by using a robotic arm. The framework consists of a simulation stage and a robotic drawing stage. In the simulation stage, geometrical contours were automatically extracted from a certain viewpoint and a neural network was employed to create simplified contours. Then, expressive digital strokes were generated after interactive editing according to user's aesthetic understanding. In the robotic drawing stage, an optimization method was presented for drawing smooth and physically consistent strokes to the digital strokes, and two oriental ink painting styles termed as Noutan (shade) and Kasure (scratchiness) were applied to the strokes by robotic control of a brush's translation, dipping and scraping. Unlike existing methods that concentrate on generating paintings from 2D images, our framework has the advantage of rendering stylized ink paintings from 3D models by using a consumer-grade robotic arm. We evaluate the proposed framework by taking 3 standard models and a user-defined model as examples. The results show that our framework is able to draw visually pleasing oriental ink paintings with expressive strokes.