2 research outputs found
Expressive line drawings of human faces from range images
We propose a novel technique to extract features from a range image and use them to produce a 3D pen-and-ink
style portrait similar to a traditional artistic drawing. Unlike most previous template-based, component-based or
example-based face sketching methods, which work from a frontal photograph as input, our system uses a range
image as input. Our method runs in real-time for models of moderate complexity, allowing the pose and drawing
style to be modied interactively.
Portrait drawing in our system makes use of occluding contours and suggestive contours as the most important
shape cues. However, current 3D feature line detection methods require a smooth mesh and cannot be reliably
applied directly to noisy range images. We thus present an improved silhouette line detection algorithm.
Feature edges related to the signicant parts of a face are extracted from the range image, connected, and
smoothed, allowing us to construct chains of line paths which can then be rendered as desired.
We also incorporate various portrait-drawing principles to provide several simple yet eective non-photorealistic
portrait renderers such as a pen-and-ink shader, a hatch shader and a sketch shader. These are able to generate
various life-like impressions in dierent styles from a user-chosen viewpoint. To obtain satisfactory results, we
rene rendered output by smoothing changes in line thickness and opacity. We are careful to provide appropriate
visual cues to enhance the viewer's comprehension of the human face.
Our experimental results demonstrate the robustness and eectiveness of our approach, and further suggest that
our approach can be extended to other 3D geometric objects