DCT的相似性及其在图像匹配中的应用

Similarity of DCT and application in image matching

从理论上研究了图像在发生亮度和对比度变化、镜像或转置变化时,其DCT变换后的矩阵元素之间具有相似性。并在该特性基础上,提出了基于DCT变换的自适应图像匹配算法。鉴于图像匹配标准和抗噪声干扰的鲁棒性,可以只考虑主要能量所存在的区域。另外,图像经过DCT变换后的主要能量集中在左上角,因此,只匹配DCT变换后左上角子矩阵,即可以满足匹配要求。实验证明该方法十分有效。

The similarity of the element of matrix after DCT is studied by theory with changing of brightness or contrasts, and with transformation of mirroring or transposing. On the other hand, by making full use of the characteristic, an adaptive matching approach based on DCT is proposed. With respect to matching criterion and robustness of noise interference, attention is mainly given to a majority of energy, so it can meet the demand when only matching a few elements of matrix on the upper-left corner after transform. Experimental result proves that the method based on DCT is perfect.