The document describes an approach called Sparse Kernel Continuous Relevance Model (SKL-CRM) for image annotation. SKL-CRM learns data-adaptive visual kernels to better combine different image features like GIST, SIFT, color, and texture. It introduces a binary kernel-feature alignment matrix to learn which kernel functions are best suited to which features by directly optimizing annotation performance on a validation set. Evaluation on standard datasets shows SKL-CRM improves over baselines with fixed 'default' kernels, achieving a relative gain of 10-15% in F1 score.