In order to segment each LED pixels from the image which is acquired by CCD and is used to brightness correction

a method based on optimal threshold segmentation with area constraint has been proposed. Based on optimal threshold method

taking prior information into account

an area constraint is introduced to restrain the range of threshold. Compared with traditional method

it is well done to avoid the LED region segmented connecting together. In the optimal threshold method with area constraint

the histogram of the captured image is generated

using the method of optimal threshold with area constraint

the optimal threshold is acquired. Finally

the optimal threshold method is used to segment the captured image. Experiments demonstrate that it is good to use this method to segment the LED pixels from the captured image

and also it can avoid the segmented region of LED pixels with a dense distribution connecting together.