Multimedia algorithms deal with enormous amounts of data transfers and storage, resulting in huge bandwidth requirements at the off-chip memory and system bus level. As a result the related energy consumption becomes critical. Even for execution time the bottleneck can shift from the CPU to the external bus load. This paper demonstrates a systematic software approach to reduce this system bus load. It consists of source-to-source code transformations, that have to be applied before the conventional ILP compilation. To illustrate this we use a cavity detection algorithm for medical imaging, that is mapped on a general-purpose programmable processor.