The widespread adoption of the JPEG2000 standard calls for the development of computationally efficient algorithms to analyze the content of imagery compressed using this standard. For this purpose, we propose the use of the information content (IC) of wavelet subbands, defined as the number of bytes that JPEG2000 spends to encode the subbands. The IC of subbands can be obtained from the packet headers of the JPEG2000 codestream, thereby avoiding decompressing the arithmetically encoded bitplane data. We present experimental results for two content analysis tasks; namely, image classification and scene change detection. Our results indicate that performance comparable to that of methods operating on decompressed data can be achieved, while saving computational and bandwidth resources.