Wireless capsule endoscopy is used to capture images from inside body which are used for diagnosis of various diseases. Diagnosis of disease and detail analysis of endoscopic images is based on the quality of image which is heavily dependent on the image size, frame rate and illumination system. The design of illumination system involves choice and placement of proper light source. Light emitting diodes (LED) are widely used as light source for illumination. The brightness in a captured image depends on the distance of the object from the light source and surrounding environment. In this paper, we propose a new algorithm that uses the captured image for determining the proper illumination condition for future frames. Based on it, the brightness of the LEDs is controlled individually in real-time to give proper illumination for clear image acquisition.