Improved Image Retargeting by Distinguishing between Faces in Focus and Out of Focus

The identification of relevant objects in an image is highly relevant in the context of image retargeting. Especially faces draw the attention of viewers. But the level of relevance may change between different faces depending on the size, the location, or whether a face is in focus or not. In this paper, we present a novel algorithm which distinguishes in-focus and out-of-focus faces. A face detector with multiple cascades is used first to locate initial face regions. We analyze the ratio of strong edges in each face region to classify out-of-focus faces. Finally, we use the Grab Cut algorithm to segment the faces and define binary face masks. These masks can then be used as an additional input to image retargeting algorithms.

[1]  Jian Shi,et al.  Image Retargeting Using Mesh Parametrization , 2009, IEEE Transactions on Multimedia.

[2]  Andrew Blake,et al.  "GrabCut" , 2004, ACM Trans. Graph..

[3]  Carlo Tomasi,et al.  Alpha estimation in natural images , 2000, Proceedings IEEE Conference on Computer Vision and Pattern Recognition. CVPR 2000 (Cat. No.PR00662).

[4]  Yael Pritch,et al.  Shift-map image editing , 2009, 2009 IEEE 12th International Conference on Computer Vision.

[5]  Yoav Freund,et al.  A decision-theoretic generalization of on-line learning and an application to boosting , 1995, EuroCOLT.

[6]  Olga Sorkine-Hornung,et al.  A comparative study of image retargeting , 2010, ACM Trans. Graph..

[7]  Alan C. Bovik,et al.  Handbook of Image and Video Processing (Communications, Networking and Multimedia) , 2005 .

[8]  Mohan M. Trivedi,et al.  Head Pose Estimation in Computer Vision: A Survey , 2009, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[9]  Paul A. Viola,et al.  Rapid object detection using a boosted cascade of simple features , 2001, Proceedings of the 2001 IEEE Computer Society Conference on Computer Vision and Pattern Recognition. CVPR 2001.

[10]  Azriel Rosenfeld,et al.  Face recognition: A literature survey , 2003, CSUR.

[11]  S. Avidan,et al.  Seam carving for content-aware image resizing , 2007, SIGGRAPH 2007.

[12]  Jerry D. Gibson,et al.  Handbook of Image and Video Processing , 2000 .

[13]  S. Avidan,et al.  Multi-operator media retargeting , 2009, SIGGRAPH 2009.

[14]  O. Sorkine,et al.  Optimized scale-and-stretch for image resizing , 2008, SIGGRAPH 2008.

[15]  Ariel Shamir,et al.  Cropping Scaling Seam carving Warping Multi-operator , 2009 .

[16]  Wolfgang Effelsberg,et al.  SeamCrop for image retargeting , 2012, Electronic Imaging.

[17]  Ariel Shamir,et al.  Seam Carving for Content-Aware Image Resizing , 2007, ACM Trans. Graph..

[18]  Wolfgang Effelsberg,et al.  SeamCrop: changing the size and aspect ratio of videos , 2012, MoVid '12.