The invention provides a scanner for scanning a surface having a one-dimensional optical sensor and no mechanical moving parts for determining the scanning speed. A method is also provided for processing a text image obtained by scanning a text with a scanner, where the text image is distorted due to variability of the instantaneous scanning speed. The method utilizes the mode character height and font ration for each font in the text obtaining a local correction factor at each location in the text image. The correction factor is related to the instantaneous scanning speed at the location and is used to correct the distorted text image.