1. A method implemented in a data processing apparatus for processing a set of multiple input images of a scene taken at various exposure values, comprising: (a) using one or more of the multiple input images, classifying the scene into one of a plurality of scene classes, wherein the plurality of scene classes either include a class of scenes that contains a significant presence of people, a class of outdoor scenes and a class of indoor scenes, or include a class of scenes that contains a significant presence of people, a class of daylight scenes and a class of night scenes, wherein step (a) comprises: (a1) selecting a subset of two or more images from the multiple input images; (a2) down-sampling the selected images; (a3) after down-sampling, fusing the selected images into a single fused image, by generating a weight map for each selected image and combining the selected images using the weight maps, the weight maps being generated based on only one of saturation, contrast, and well-exposedness of each pixel in each selected image; and (a4) classifying the fused image into one of the plurality of scene classes; (b) based on the scene class determined in step (a), selecting one of a plurality of pre-stored tone mapping operators; (c) merging the multiple input images to generate a high dynamic range (HDR) image; (d) tone mapping the HDR image using the tone mapping operator selected in step (b) to generate a low dynamic range (LDR) image; (e) based on the scene class determined in step (a), selecting one of a plurality of pre-stored gamut mapping algorithms; and (f) using the gamut mapping algorithm selected in step (e), converting the LDR image generated in step (d) from a color space of the image to a color space of an output device.