Figure 2 The proposed image processing routines to automatically locate the center of LEDs.
image
It is further noted that the processes to produce both black and white counterparts still required some user intervention. This is performed in order to set the level at which all background and unwanted defects; i.e. internal holes and background resulting from a non-uniform illumination, within the images are removed as much as possible. In addition, the manual removal of some imperfections in the intermediate image resulting from adding the images from the left and right sides is required.
Software Implementation of the Proposed Routines
The proposed image processing routines detailed in the previous section were implemented on a personal computer in order to verify their functional correctness. Matlab version 7.0 was mainly used as a software development tool. The developed application running on the Windows XP machine is responsible for retrieving the RGB image of an LED array, producing the intermediate images following the proposed routines and supporting appropriate user interventions to adjust the black and white levels and remove defects. The final outcome image is also displayed by the application. Figure 3 shows the screen capture of the application as a whole.