Cell Extraction and Horizontal-Scale Correction in Structured Documents

Preprocessing techniques form an important task in document image analysis. In structured documents like forms, cheques, etc., there is a predefined space called frame field/cell for the user to fill the entry. When the user is writing, the nonuniformity of inter-character spacing becomes an issue. Many times, the starting characters of the word are written with sparse spacing between the characters and then gradually with a more compact spacing so as to accommodate the word within the frame field. To deal with this variation in intra-word spacing, horizontal-scale correction is applied to the extracted form fields. The effectiveness of the system is proved by applying it as a preprocessing step in a recognition system proposed in (Almazán et al. in Pattern Anal Mach Intell 36(12):21552–2566, 2014 [2]). The recognition framework results in reduced error rates with this normalization.