An image represented by multiple nodes can be processed by determining whether information can be propagated to a node from another node (e.g., source node) of the image, thereby allowing significantly greater parallelism and scalability by taking advantage of multiprocessing or multi-core processors that are prevalent and widely available today. Conceptually, an image can be presented as a “structured grid” of multiple nodes (e.g., a structured grid of pixels of an image). In a “structured grid,” two or more of the nodes can determine whether to propagate information in parallel. In fact, each node of a “structured grid” can perform operations relating to propagation of information in parallel. This means that for an image of N pixels, it is possible to perform N operations in parallel. It is also possible to divide the processing of N operations for N pixels substantially equally between the number processors or processing cores available at a given time.