1. A method for determining a quality measure for a video image, comprising steps of selecting a first encoding unit of the video image as a measuring point; determining a context area of the selected first encoding unit, the context area comprising said selected first encoding unit and at least portions of a plurality of second encoding units that are directly adjacent to the selected first encoding unit; calculating a variance of pixel values in the context area; calculating a variance of pixel values in the selected first encoding unit; calculating a relation between the variance of pixel values in the selected first encoding unit and the variance of pixel values in the context area; and averaging for a plurality of selected first encoding units said relations, wherein a quality measure for a video image is obtained.