A gradient domain compression system generates, from an input image having
a high luminance dynamic range, an output image having a lower luminance
dynamic range. The system comprises a gradient image generator module, a
gradient compression module, and an output image generator module. The
gradient image generator module is configured to generate, from the input
image, a gradient image representing, for respective points of the input
image, gradient values in the luminance of the input image. The gradient
compression module is configured to receive the gradient image and
generate a compressed range gradient image in which the range of gradient
values are compressed. The output image generator module is configured to
receive the compressed range gradient image and to generate therefrom an
image, the image generated by the output image generator module
comprising the output image.