A New Invariant Algorithm for Recognition of Alphabets of Multi- lingual Documents

In this paper, we have proposed a new algorithm which is invariant to image transformations such as Rotation, Scaling and Translation (RST), to recognize the alphabets of different languages such as Kannada, Telugu, Tamil, Malayalam, Parsian, English-upper case, English-lower case and numerals. The method maps the spatial coordinates of the image to polar coordinates of polar domain. The features are extracted by counting number of black pixels and white pixels in each ring. These features are invariant to RST. The method gives less accuracy. To improve the accuracy we have introduced a new method based on distance measures such as Euclidian and city-block. This algorithm extracts features by estimating distance between the first black pixel and centroid and last black pixel and centroid in 8 directions. However, this method is not invariant to rotation and scaling [16].