Abstract: The values of an attribute, like color, to be assigned to the right and left half of a pixel of a display device, such as may be determined by a computer image generation system, are compared for determining a difference value. If the difference value is less than a predetermined threshold, an average of the left and right half values is assigned to the pixel. If the difference value is greater than or equal to the threshold, then the right and left half values are assigned to the respective right and left halves of the pixel and during the raster scan, the attribute value of the pixel to be displayed is transitioned at the beginning of the pixel interval and in the middle of the pixel interval so that the pixel presents an image in response to the corresponding right and left half values. The data for the left and right half values may be truncated and stored as a portion of the data word or may be encoded into logarithmetic form having a mantissa and shift code.