The application can double-buffer images coming from camera. Keep capturing image while the graph is executing. Here are the steps:
[S1]. allocate two buffers for camera capture (i.e., using malloc)
[S2]. create input image using vxCreateImageFromHandle with one of the buffers in S1
[S3]. build the graph using vx_image object created in S2 and call vxVerifyGraph
[S4]. call vxSwapImageHandle with buffer with camera data prior to calling vxProcessGraph
You could also double-buffer the output.
Another approach is to use vx_delay object with two delay elements for double buffering.
Hope that helps.