Towards Efficient Parallel Image Processing on Cluster Grids Using GIMP

As it is not realistic to expect that all users, especially specialists in the graphic business, use complex low-level parallel programs to speed up image processing, we have developed a plugin for the highly acclaimed GIMP which enables to invoke a series of filter operations in a pipeline in parallel on a set of images loaded by the plugin. We present the software developments, test scenarios and experimental results on cluster grid systems possibly featuring singleprocessors and SMP nodes and being used by other users at the same time. Behind the GUI, the plugin invokes a smart DAMPVM cluster grid shell which spawns processes on the best nodes in the cluster, taking into account their loads including other user processes. This enables to select the fastest nodes for the stages in the pipeline. We show by experiment that the approach prevents scenarios in which other user processes or even slightly more loaded processors become the bottlenecks of the whole pipeline. The parallel mapping is completely transparent to the end user who interacts only with the GUI. We present the results achieved with the GIMP plugin using the smart cluster grid shell as well as a simple round robin scheduling and prove the former solution to be superior.