A method for pre-dithering images to be coded by an encoder, the method comprising: receiving an input of low dynamic range image in a first bit depth to be encoded by the encoder at a target bit rate, wherein low dynamic range is also referred to as standard dynamic range; generating a random noise image of uniformly-distributed noise; filtering (200A-1; 200B-1) the random noise image with a spatial filter to generate a spatial-filtered noise image (206; 220); storing the spatial-filtered noise image in a ring buffer; repeating the generation of the spatial-filtered noise images (206; 220) and storing the same in the ring buffer; applying (200A-2; 200B-2) a temporal filter to images in the ring buffer to generate a temporal-filtered noise image (216; 240); adding the temporal-filtered noise image to the input LDR image to generate a noise-enhanced LDR image; and quantizing the noise-enhanced image to a second bit-depth to generate an output dithered LDR image, wherein the second bit-depth is lower than the first bit depth, wherein the spatial filter is based on a low-pass filter representation of the optical transfer function, OTF, of the human visual system; wherein the spatial filter and the temporal filter are low-pass filters, or the spatial filter and the temporal filter are high-pass filters; wherein in case of the spatial filter being a high-pass filter generating (200A-1) the spatial-filtered noise image comprises: filtering the random noise image with the OTF-based low pass filter to generate a low-pass filtered noise image; and subtracting the low-pass filtered noise image from the random noise image to generate a high-pass spatial-filtered noise image; and wherein in case of the spatial filter being a low-pass filter generating (200B-1) the spatial-filtered noise image comprises: filtering the random noise image with the OTF-based low-pass filter to generate a low-pass filtered noise image; and subtracting from the low-pass filtered noise image its average to generate a low-pass spatial-filtered noise image, the method further comprising: determining whether the target bit rate is a low bit rate; and for the spatial and temporal filtering steps: if the target bit rate is determined to be a low bit rate, selecting the low-pass spatial filter and a low-pass temporal filter, otherwise selecting the high-pass spatial filter and a high-pass temporal filter. receiving an input of low dynamic range image in a first bit depth to be encoded by the encoder at a target bit rate, wherein low dynamic range is also referred to as standard dynamic range; generating a random noise image of uniformly-distributed noise; filtering (200A-1; 200B-1) the random noise image with a spatial filter to generate a spatial-filtered noise image (206; 220); storing the spatial-filtered noise image in a ring buffer; repeating the generation of the spatial-filtered noise images (206; 220) and storing the same in the ring buffer; applying (200A-2; 200B-2) a temporal filter to images in the ring buffer to generate a temporal-filtered noise image (216; 240); adding the temporal-filtered noise image to the input LDR image to generate a noise-enhanced LDR image; and quantizing the noise-enhanced image to a second bit-depth to generate an output dithered LDR image, wherein the second bit-depth is lower than the first bit depth, wherein the spatial filter is based on a low-pass filter representation of the optical transfer function, OTF, of the human visual system; wherein the spatial filter and the temporal filter are low-pass filters, or the spatial filter and the temporal filter are high-pass filters; wherein in case of the spatial filter being a high-pass filter generating (200A-1) the spatial-filtered noise image comprises: filtering the random noise image with the OTF-based low pass filter to generate a low-pass filtered noise image; and subtracting the low-pass filtered noise image from the random noise image to generate a high-pass spatial-filtered noise image; and filtering the random noise image with the OTF-based low pass filter to generate a low-pass filtered noise image; and subtracting the low-pass filtered noise image from the random noise image to generate a high-pass spatial-filtered noise image; and wherein in case of the spatial filter being a low-pass filter generating (200B-1) the spatial-filtered noise image comprises: filtering the random noise image with the OTF-based low-pass filter to generate a low-pass filtered noise image; and subtracting from the low-pass filtered noise image its average to generate a low-pass spatial-filtered noise image, filtering the random noise image with the OTF-based low-pass filter to generate a low-pass filtered noise image; and subtracting from the low-pass filtered noise image its average to generate a low-pass spatial-filtered noise image, the method further comprising: determining whether the target bit rate is a low bit rate; and for the spatial and temporal filtering steps: if the target bit rate is determined to be a low bit rate, selecting the low-pass spatial filter and a low-pass temporal filter, otherwise selecting the high-pass spatial filter and a high-pass temporal filter. determining whether the target bit rate is a low bit rate; and for the spatial and temporal filtering steps: if the target bit rate is determined to be a low bit rate, selecting the low-pass spatial filter and a low-pass temporal filter, otherwise selecting the high-pass spatial filter and a high-pass temporal filter.