Importance prioritization coding in JPEG2000 for interpretability with application to surveillance imagery

Surveillance imagery is used for supporting the decision processes in strategic, operational and tactical tasks. The visual tasks associated with the interpretation of such imagery may require the detection of targets or the recognition of image contents. It is important for an image compression scheme to be tuned to maximise the imagery's interpretability (or content recognition) performance. Importance prioritisation coding of an image, where image contents are prioritised in order of importance for interpretability, is hence a very desirable feature for such applications. The paper presents a flexible framework for such prioritisation in JPEG2000 using regions of interests (ROIs) and importance maps. The coding scheme allows multiple and arbitrary shaped ROIs to be defined at different spatial locations, sub-band orientations and scale, and subsequently be prioritised using arbitrary importance scores. No ROI or importance map information need to be signalled to the decoder, and progressive lossy to lossless reconstruction of ROIs and the background is also possible. Furthermore, the prioritisation maintains the JPEG2000 code-stream syntax and can be decoded by any generic JPEG2000 decoder.