Realtime Depth of Field Rendering with Bokeh Effect via Interactive Depth Labeling

Shallow focus is a kind of photographic technique, which means taking a picture with a small depth of field (DOF) so that the objects outside of the DOF will be blurred to highlight the subject inside of the DOF. Common digital cameras, unlike the Digital Single Lens Reflex Camera (DSLR), cannot produce this special vision effect due to its limitations in aperture and focal length. Commercial softwares and even some common digital cameras are endued with built-in shallow focus simulation programs. However, the rendering quality of the existing tools is not very well due to several problems: 1) boundaries of the focused objects are often over smoothed caused by poor auto-generated object segmentation result, 2) the blurring effect usually looks fake since the element of image formation principle, i.e. the depth of the object, is not properly utilized in the rendering process, and 3) even though some refocusing methods model the blurring effect with depth information, it is hard to extract accurate depth map from a single image. Therefore, we develop a friendly user interface which can interactively achieve reliable depth labeling based on the techniques of semi-automatic object segmentation and 3D modeling. Moreover, to realize shallow focus effect efficiently, we apply a real-time gather-based DOF rendering method and modify it to be capable of simulating the bokeh effect.