11. Method according to claim 1 , wherein the third elimination step comprises: performing projective correction on the basis of each identified horizontal vanishing point candidate; comparing the proximity of each horizontal vanishing point candidate to the resulting horizontal text direction after projective correction; and selecting the horizontal vanishing point candidate which is closest to the horizontal text direction of the image document after projective correction.
1. A method for projective correction of an image containing at least one text portion that is distorted by perspective, the method comprising the steps of: image binarization, wherein said image is binarized; connected component analysis, wherein pixel blobs are detected in said at least one text portion of said binarized image and wherein for each of said pixel blobs a position determining pixel is selected on a pixel blob baseline of the pixel blob, said position determining pixel defining the position of the pixel blob in the binarized image; horizontal vanishing point determination, comprising the steps of: estimating text baselines by means of said position determining pixels of said pixel blobs, identifying horizontal vanishing point candidates from said estimated text baselines, and determining a horizontal vanishing point of said at least one text portion by means of said horizontal vanishing point candidates; vertical vanishing point determination, wherein a vertical vanishing point is determined for said at least one text portion on the basis of vertical features thereof; and projective correction, wherein said perspective in said image is corrected on the basis of said horizontal and vertical vanishing points; wherein said horizontal vanishing point determination comprises a first elimination step on the level of said position determining pixels, a second elimination step on the level of text baselines and a third elimination step on the level of horizontal vanishing point candidates.