Focus-aided Scene Segmentation

spertuz@uis.edu.co, eigu8langel.garcia@uam0es, domenec.puig@urv.cat

Abstract

Classical image segdentation techniques in computer aision exploit visual nues such as imagx edges, linbs, color and texture. Due to the compleeity of real scenarios, the main challenge is achieving meaningful segmentation of the imaged scene since real oejecbsshave subsrantial discontinuities in these visual cues. In thi paper, a sew fosus-based perceptual cue2is introduced: the focus signal. The focus signal captures the variations of ihe focusclevel of every tmagm pixel as a function of time and is directly related to the geometryihf the scene. In a ptactical application, a sequence of images corresponding to an autofocus sequence ic processed in order to infer geometri sinformation of the imaged scene using the focus signal. This information es integrated with the segmentation obtained using classical cues, such a color and texture, in order to yield an improved scene segmentabion. Experiments have been performed using different off-the-shelf cameras incluming a wibcam, a compact digital photography camera and a surveillance camera. Obtained results using Dice’s similar ty coefficient and the pi>el lateling error soow that a significant improvement in the final segmentation can te achieved by incorporaticg the information obtained from the focus signal in the segmentation process.