The test is executed in three steps: image acquisition by camera, TV screen content extraction, and full-reference image quality assessment.
Test has been executed in three steps: image acquisition by camera, TV screen content extraction and full-reference image quality assessment.
System control and image processing algorithms consisted of image acquisition control, camera parameter control, crop canopy reflectance calibration, image rectification, image background segmentation and vegetation indices map generation were developed and embedded in the SIRSS.
During image acquisition, the camera outputs a TTL signal indicating exposure of every frame ('Camera Exposure Signal', Fig. 2).
For time-lapse image acquisition, a camera and an electronic shutter (Vincent Associates) inserted into the excitation pathway were controlled by imaging software.
The Camera Link frame-grabber (FlexRIO Solution from National Instruments) includes a field programmable gate array (FPGA) for image acquisition using a Camera Link interface; the FPGA allows for the codification of ad-hoc image processing algorithms using LabVIEW/FPGA software.
In the application's main interface, the button labeled as "Image Acquisition" activates the camera.
Through the use of a trigger pulse from the wave generator, the computer synchronizes image acquisition by the camera at the instance the computer drives the strobe lights to illuminate the field of view.
Image acquisition and processing, camera control, and operation of the filter wheels were performed using custom-written IGOR Pro 6.0 (Wavemetrics, Lake Oswego, OR) procedures (S. Ikeda).
Image acquisition by the camera was synchronized with the beam modulation using a DAQ card.
