Wikipedia
The Nikon Expeed image/ video processors (often styled EXPEED) are media processors for Nikon's digital cameras. They perform a large number of tasks: Bayer filtering, demosaicing, image sensor corrections/ dark-frame subtraction, image noise reduction, image sharpening, image scaling, gamma correction, image enhancement/Active D-Lighting, colorspace conversion, chroma subsampling, framerate conversion, lens distortion/ chromatic aberration correction, image compression/ JPEG encoding, video compression, display/ video interface driving, digital image editing, face detection, audio processing/ compression/ encoding and computer data storage/ data transmission.
EXPEED's multi-processor system on a chip solution integrates an image processor in multi-core processor architecture, with each single processor-core able to compute many instructions/operations in parallel. Storage and display interfaces and other modules are added and a digital signal processor (DSP) increases the number of simultaneous computations. An on-chip 32-bit microcontroller initiates and controls the operation and data transfers of all processors, modules and interfaces and can be seen as the main control unit of the camera.
In each generation Nikon uses different versions for its professional and consumer DSLRs / MILCs, whereas its compact cameras use totally different architectures. This is different from for example Canons DIGIC: its professional DSLRs double the processors of its consumer DSLR series. The Expeed is an application-specific integrated circuit (ASIC) built by Fujitsu specifically for Nikon designs according to Nikon specifications.