Figure 1 : The multi operator algorithm uses dynamic programming to find the optimal combination of retargeting operators. Here we show a comparison of several methods. The original image (left) is retargeted using: simple cropping, uniform scaling, seam carving [Rubinstein et al. 2008 ], non-uniform warping [Wang et al. 2008] and our multi-operator algorithm. In this example, the multi-operator algorithm combines cropping, scaling and seam carving to optimize our new image-to-image similarity

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... easure, termed Bidirectional Warping (BDW). The algorithm can use other retargeting operators and similarity measures. Abstract Content aware resizing gained popularity lately and users can now choose from a battery of methods to retarget their media. However, no single retargeting operator performs well on all images and all target sizes. In a user study we conducted, we found that users prefer to combine seam carving with cropping and scaling to produce results they are satisfied with. This inspires us to propose an algorithm that combines different operators in an optimal manner. We define a resizing space as a conceptual multi-dimensional space combining several resizing operators, and show how a path in this space defines a sequence of operations to retarget media. We define a new image similarity measure, which we term Bi-Directional Warping (BDW), and use it with a dynamic programming algorithm to find an optimal path in the resizing space. In addition, we show a simple and intuitive user interface allowing users to explore the resizing space of various image sizes interactively. Using key-frames and interpolation we also extend our technique to retarget video, providing the flexibility to use the best combination of operators at different times in the sequence.