Study On High Dynamic Range Image Displaying Algorithm

Today displaying a range image is becoming more and more important in many fields, such as digital photography,film processing,scientific image enhancement,virtual reality,computer vision,pattern recognition and so on. With the development of the digital technology, there is a higher requirement for the image displaying technology in both digital image filed and video filed. How to get a better visual output in a low dynamic range output device is now an important subject.According to the subject, this paper presents a summary of previous results and proposes a local adaptation algorithm of compressing high dynamic range images based on gradient attenuation to fit conventional display devices that are only capable of outputting a low dynamic range.This algorithm can solve the digital image tone mapping problem and have excellent displaying result adaptively according to the gradient. Based on Gaussian pyramid, the algorithm compresses the gradient according to the amplitudes, and then gets the luminance image through FFT to solve the Poisson function. Experimental results show the algorithm of manipulating the gradient field of luminance image by attenuating the large gradients'magnitudes can preserve fine details avoiding common artifacts, such as halos, gradient reversals, or loss of local contrast. In addition, this algorithm can be not only used in personal computer but also in embedded equipments.