4. The grayscale character dictionary generation apparatus according to claim 1 , further comprising: a 1st synthetic grayscale degraded character dictionary generation unit for linear transformation of the template of each of the clusters using the transformation matrix to generate a 1st synthetic grayscale character dictionary.
4. The grayscale character dictionary generation apparatus according to claim 1 , further comprising: a 1st synthetic grayscale degraded character dictionary generation unit for linear transformation of the template of each of the clusters using the transformation matrix to generate a 1st synthetic grayscale character dictionary. 5. The grayscale character dictionary generation apparatus according to claim 4 , wherein the 1st synthetic grayscale degraded character image generation unit includes: a degradation level estimation unit, for estimating degradation levels of the synthetic characters required to be generated, with different degradation levels corresponding to different degradation extents; and, a degraded grayscale character generation unit, for generating synthetic grayscale degraded character images corresponding to each of the degradation levels respectively for each of the inputted binary character images; the transformation matrix generation unit generates the transformation matrix using Principle Component Analysis method; the 2nd synthetic grayscale degraded character dictionary generation unit constructs eigenspace of each category of the synthetic grayscale degraded character using Principle Component Analysis method.