Multispectral imaging produces large amounts of data which extend processing, transmission and storage systems to their upper limits. Although there are several interface standards specific to image data acquisition, such as CameraLink, it is Firewire which provides a high-speed data bus, integrated control capability, without loss of flexibility, and which is commonly available as a low cost solution.
The class of multispectral imaging requires a different treatment of the processing principals than standard imaging. The same spatial region is captured multiple times using different optical wavelengths. This technique finds application in such diverse areas as coastal monitoring, fruit sorting and automated agriculture. Modifications and additional features to the camera operating and configuration parameters are therefore required which are not generally present with conventional imaging sensors.
This paper describes extensions to the IIDC Digital Camera (D-Cam) specification in the development of a Firewire technology platform for transmitting the data structures described and for providing real-time, online control of spectral information acquisition. Additionally, it describes how a set of registers in the sub-unit architecture of the Firewire protocol is augmented to accommodate the demands of a multispectral system. The extensions are specification conformant and do not alter underlining compliance with the base standard. The paper also describes the implementation of the extended D-Cam in the Firewire subsystem of a smart multispectral camera used in commercial applications.