An image acquisition system comprising: an illumination device for illuminating a scene ; an image sensor comprising a plurality of groups of sensor elements , each group of sensor elements providing a subspectral image of the scene by sensing a different spectral portion of the electromagnetic spectrum, preferably of the visible spectrum; a controller configured to control: the image sensor for acquiring a set of subspectral images of the scene during an acquisition time duration, and the illumination device for providing a given sequence of illuminations at different wavelengths during said given time duration (T); and an unmixer configured to provide a plurality of sequences of output images of the scene , each sequence comprising a plurality of output images at different times (T i-2 , T i-1 , T i ) separated by a given time interval, each output image being derived from a plurality of said subspectral images acquired during the same acquisition time duration (T); wherein the scene illuminated by at least one of said illumination (241-243) is sensed by at least two of said groups of sensor elements ; and wherein the unmixer is configured to provide a first output image at a first said time (T i-2 ) by: obtaining a first set of weighted subspectral images by weighting at least a portion of each subspectral image of the set according to spectral reconstruction contributions derived from spectral contributions of said illuminations to each group of sensor elements, and combining the weighted subspectral images ) of said first set at said first time (T i-2 ). an illumination device for illuminating a scene ; an image sensor comprising a plurality of groups of sensor elements , each group of sensor elements providing a subspectral image of the scene by sensing a different spectral portion of the electromagnetic spectrum, preferably of the visible spectrum; a controller configured to control: the image sensor for acquiring a set of subspectral images of the scene during an acquisition time duration, and the illumination device for providing a given sequence of illuminations at different wavelengths during said given time duration (T); and the image sensor for acquiring a set of subspectral images of the scene during an acquisition time duration, and the illumination device for providing a given sequence of illuminations at different wavelengths during said given time duration (T); and an unmixer configured to provide a plurality of sequences of output images of the scene , each sequence comprising a plurality of output images at different times (T i-2 , T i-1 , T i ) separated by a given time interval, each output image being derived from a plurality of said subspectral images acquired during the same acquisition time duration (T); wherein the scene illuminated by at least one of said illumination (241-243) is sensed by at least two of said groups of sensor elements ; and wherein the unmixer is configured to provide a first output image at a first said time (T i-2 ) by: obtaining a first set of weighted subspectral images by weighting at least a portion of each subspectral image of the set according to spectral reconstruction contributions derived from spectral contributions of said illuminations to each group of sensor elements, and combining the weighted subspectral images ) of said first set at said first time (T i-2 ). obtaining a first set of weighted subspectral images by weighting at least a portion of each subspectral image of the set according to spectral reconstruction contributions derived from spectral contributions of said illuminations to each group of sensor elements, and combining the weighted subspectral images ) of said first set at said first time (T i-2 ). <EOS>