Compatibility between items, such as clothes and shoes, is a major factor among customer's purchasing decisions. However, learning "compatibility" is challenging due to (1) broader notions of compatibility than those of similarity, (2) the asymmetric nature of compatibility, and (3) only a small set of compatible and incompatible items are observed. We propose an end-to-end trainable system to embed each item into a latent vector and project a query item into K compatible prototypes in the same space. These prototypes reflect the broad notions of compatibility. We refer to both the embedding and prototypes as "Compatibility Family." In our learned space, we introduce a novel Projected Compatibility Distance (PCD) function which is differentiable and ensures diversity by aiming for at least one prototype to be close to a compatible item, whereas none of the prototypes are close to an incompatible item. We evaluate our system on a toy dataset, two Amazon product datasets, and Polyvore outfit dataset. Our method consistently achieves state-of-the-art performance. Finally, we show that we can visualize the candidate compatible prototypes using a Metric-regularized Conditional Generative Adversarial Network (MrCGAN), where the input is a projected prototype and the output is a generated image of a compatible item. We ask human evaluators to judge the relative compatibility between our generated images and images generated by CGANs conditioned directly on query items. Our generated images are significantly preferred, with roughly twice the number of votes as others.

We propose a new framework for performing object segmentation and detection simultaneously. Our method leverages with an MRF graphical model that comprises two kinds of nodes and two types of labels for inference. Specifically, we decompose an image into super pixels and generate segment proposals from each super pixel. The super pixels are then duplicated to form the two types of nodes. For each segmentation node, the model is to predict the object class label, while it is to decide the label corresponding to the best segment proposal selection at each detection node. The former is clearly a segmentation problem and the latter a detection problem. We link the two tasks by establishing a unified energy function that has a joint energy term accounting for the compatibility of the segmentation and detection labelings. Marginalizing by fixing either type of variables, the energy function can be switched into the one specifically for detection or segmentation. This property enables an alternating procedure to conveniently obtain the optimal labelings. To better explain the geometry about the objects and the scene, we use the depth information so that 3-D distances between super pixels are available in computing each energy term. Experimental results on a dataset with depth information are provided to support the effectiveness of our method.

We address two key issues of co-segmentation over multiple images. The first is whether a pure unsupervised algorithm can satisfactorily solve this problem. Without the user's guidance, segmenting the foregrounds implied by the common object is quite a challenging task, especially when substantial variations in the object's appearance, shape, and scale are allowed. The second issue concerns the efficiency if the technique can lead to practical uses. With these in mind, we establish an MRF optimization model that has an energy function with nice properties and can be shown to effectively resolve the two difficulties. Specifically, instead of relying on the user inputs, our approach introduces a co-saliency prior as the hint about possible foreground locations, and uses it to construct the MRF data terms. To complete the optimization framework, we include a novel global term that is more appropriate to co-segmentation, and results in a submodular energy function. The proposed model can thus be optimally solved by graph cuts. We demonstrate these advantages by testing our method on several benchmark datasets.

We present a novel computational model to explore the relatedness of objectness and saliency, each of which plays an important role in the study of visual attention. The proposed framework conceptually integrates these two concepts via constructing a graphical model to account for their relationships, and concurrently improves their estimation by iteratively optimizing a novel energy function realizing the model. Specifically, the energy function comprises the objectness, the saliency, and the interaction energy, respectively corresponding to explain their individual regularities and the mutual effects. Minimizing the energy by fixing one or the other would elegantly transform the model into solving the problem of objectness or saliency estimation, while the useful information from the other concept can be utilized through the interaction term. Experimental results on two benchmark datasets demonstrate that the proposed model can simultaneously yield a saliency map of better quality and a more meaningful objectness output for salient object detection.

This paper describes a novel graphical model approach to seamlessly coupling and simultaneously analyzing facial emotions and the action units. Our method is based on the hidden conditional random fields (HCRFs) where we link the output class label to the underlying emotion of a facial expression sequence, and connect the hidden variables to the image frame-wise action units. As HCRFs are formulated with only the clique constraints, their labeling for hidden variables often lacks a coherent and meaningful configuration. We resolve this matter by introducing a partially-observed HCRF model, and establish an efficient scheme via Bethe energy approximation to overcome the resulting difficulties in training. For real-time applications, we also propose an online implementation to perform incremental inference with satisfactory accuracy.