in a method for converting the coordinates of image data , the positions of new picture elements in a new coordinate system are calculated by means of coordinate transformation equations from the positions of initial picture elements in an initial coordinate system . the positions of the new picture elements are randomly modified in a variation range around the positions calculated by way of the coordinate transformation . for this purpose , random values are added to the calculated coordinates of the new picture elements . the method can be used in case of scale conversions , image rotation , etc . to improve the quality of the converted image . the method avoids both the corruption of the image structures caused by coordinate conversion and the formation of disruptive moire patterns . the method can be combined with known methods for calculating the color values of the new picture elements , such as the nearest - neighbor method or the interpolation method .