A method is used for specifying a bit allocation for encoding a set of images in a sequence of video images. The method computes a masking value for one or more images. The method computes a bit allocation for a current image based on the computed masking value of one or more images. The method further ascertains a total number of bits used for images that have been already encoded before computing the bit allocation. The computed bit allocation for the current image is also based on the total number of bits used. The method specifies a bit allocation for the current image by specifying a quantization parameter (QP) value for the current image. The method then adjusts the specified QP value based on a categorization of the current image.