A method of generating a piecewise-linear inter-layer prediction function for bit-depth scalable coding of high dynamic range video data, the method comprising: accessing with a processor a first group of images in a first bit depth; accessing with the processor a second group of corresponding images in a second bit depth, wherein the second bit depth is lower than the first bit depth and the first group and second group of images represent the same scene; for at least one image in the second group: filtering the image in the second group to generate a first filtered image; filtering the corresponding image in the first group to generate a second filtered image; computing a frame-significance pixel map based on the first and second filtered images, wherein the frame significance pixel map value for a pixel in an image in the second group is computed based on the absolute difference between corresponding pixel values in the first and second filtered images, multiplied by a luminance value for a corresponding pixel in the corresponding image in the first group; and computing a frame-significance histogram based on the frame significance pixel map; generating a scene-significance histogram based on the one or more computed frame-significance histograms for the images in the second group; and determining slope segments of a piecewise linear inter-layer prediction function based on the scene-significance histogram, wherein a slope for a segment in the piecewise-linear inter-layer prediction function is inversely proportional to a measure of energy in the segment under the scene-significance histogram, the measure of energy being computed based on the sum of scene-significance histogram values in the segment, wherein the first filtered image and the second filtered image are computed using an entropy filter. accessing with a processor a first group of images in a first bit depth; accessing with the processor a second group of corresponding images in a second bit depth, wherein the second bit depth is lower than the first bit depth and the first group and second group of images represent the same scene; for at least one image in the second group: filtering the image in the second group to generate a first filtered image; filtering the corresponding image in the first group to generate a second filtered image; computing a frame-significance pixel map based on the first and second filtered images, wherein the frame significance pixel map value for a pixel in an image in the second group is computed based on the absolute difference between corresponding pixel values in the first and second filtered images, multiplied by a luminance value for a corresponding pixel in the corresponding image in the first group; and computing a frame-significance histogram based on the frame significance pixel map; filtering the image in the second group to generate a first filtered image; filtering the corresponding image in the first group to generate a second filtered image; computing a frame-significance pixel map based on the first and second filtered images, wherein the frame significance pixel map value for a pixel in an image in the second group is computed based on the absolute difference between corresponding pixel values in the first and second filtered images, multiplied by a luminance value for a corresponding pixel in the corresponding image in the first group; and computing a frame-significance histogram based on the frame significance pixel map; generating a scene-significance histogram based on the one or more computed frame-significance histograms for the images in the second group; and determining slope segments of a piecewise linear inter-layer prediction function based on the scene-significance histogram, wherein a slope for a segment in the piecewise-linear inter-layer prediction function is inversely proportional to a measure of energy in the segment under the scene-significance histogram, the measure of energy being computed based on the sum of scene-significance histogram values in the segment, wherein the first filtered image and the second filtered image are computed using an entropy filter.