This chapter presents a number of methods that generate High Dynamic Range (HDR) content from Low Dynamic Range (LDR). The expansion of LDR content is achieved by transforming LDR content into HDR content using operators commonly termed expansion operator (EO). EOs are frequently referred to in the literature as inverse tone mapping operators (iTMOs) or reverse tone mapping operators (rTMOs). However, many TMOs are not invertible because they require the inversion of a partial differential equation (PDE), or other noninvertible operations. The chapter provides the MATLAB code for four operators. The method takes the following parameters as input: the maximum luminance intensity of the HDR display maxOutput and the nonlinear scaling factor. The chapter proposes an interactive system for enhancing brightness of LDR videos, targeting and showing results for DVD content. This system was to classify a scene into three components: diffuse, reflections, and light sources, and then enhances only reflections and light sources.