A robust OCR system requiring little computing capacity is obtained by first carrying out an adaptive pre-processing optimised in terms of pixel groups, which analyses the image in line segments. The most significant difference compared to previously known methods is that there is no longer a direct pattern comparison, instead the line segments are gone over in as optimum a manner as possible. The corresponding character is then deduced from the sequence of movements. As this sequence of movements can be scaled well and described in a relatively simple manner, this technique is especially suitable for mobile use. The sequence of movements of know characters is stored in a search word, such that the letters can be directly deduced from the movement. A dictionary/lexicon can also be used. If words are recognized by means of the dictionary/lexicon, the recognized letters can be used for an even more optimized character font identification. The invention is advantageous in that a robust OCR system is provided, which also requires little computing capacity. The system according to the invention is robust especially in that the recognition works better than with conventional systems even under bad conditions, especially light ratios and interferences.