image annotation by composite kernel learning with group structure
We can obtain more and more kinds of heterogeneous features (such as color, shape and texture) in images which can be extracted to describe various aspects of visual characteristics. Those high-dimensional heterogeneous visual features are intrinsically embedded in a non-linear space. In order to effectively utilize these heterogeneous features, this paper proposes an approach, called Composite Kernel Learning with Group Structure (CKLGS), to select groups of discriminative features for image annotation. For each image label, the CKLGS method embeds the nonlinear image data with discriminative features into different Reproducing Kernel Hilbert Spaces (RKHS), and then composes these kernels to select groups of discriminative features. Thus a classification model can be trained for image annotation. By the comparisons with other image annotation algorithms, experiments show that the proposed CKLGS for image annotation achieves a better performance.
image annotation composite kernel learning group structure feature selection