The invention described in this application is an image file system for the acquisition and storage of streaming digital image data onto persistent storage media in real time and for full-rate playback of streaming digital image data stored on persistent storage media. Input/output of non-streaming digital image data is processed in system memory with write/read operations buffered by native operating system input/output support. Input/output of streaming digital data is processed in high-speed streaming digital image data I/O memory with write/read operations buffered by a high-performance image buffer thread.