1. A method for quantizing floating point values of pixels of an image of an image sequence, characterized in that the method comprises: obtaining a first image from said image of the image sequence by reducing the dynamic range of said image; obtaining a test image from a second image of the image sequence, distinct of the image to-be-quantized, by: obtaining a third image from said second image by reducing the dynamic range of said second image; and obtaining said test image from said third image by quantizing the floating point values of said third image; quantizing the floating point value of at least one pixel of said image by selecting a rounding of said floating point value to either the greater whole number, the lesser whole number, or the nearest whole number according to the floating point value of a pixel of said test image.