小波变换域中图像字符的定位提取方法

在对图像中字符特点分析的基础上,研究其在小波变换域中的特征,依据这些特征提出了小波变换域中字符的定位提取方法,进一步提出采用自适应动态阈值及结合块间信息提高检测的正确率及增强算法的适应性.所提出的方法对基于JPEG2000、MPEG4等利用小波变换处理的图像中的字符定位,只需要少量的解压缩,可以提高处理的速度;同时,又能充分利用其在频域中的特点.实验结果表明,此方法具有较高的准确率.

A New Character-Localization Method in Wavelet Transform Domain

Characters in an image often provide important information of the image. Extraction of characterregions enables one to quickly browse and retrieve specific images. Based on analysis of the property of characters and study of their features in the wavelet transform domain, a new method for localizing and extracting characters is proposed. By using an adaptive dynamic threshold together with information of the adjacent blocks, the rate of correct-detection may be raised. A special feature of the method is that only partial decoding is required for encoded images involving wavelets such as JPEG2000 and MPEG4. Experimental results show that the processing is fast and correct-localization rate is high.