摘要:
针对JPEG压缩标准中直流(DC)系数和交流(AC)系数表征图像内容信息的不同,提出一种基于离散余弦变换(DCT)系数空间分布的检索算法。构造具有旋转不变性的DC系数差向量描述图像特征,根据DCT块中AC系数量化后的特点,提取AC系数分布熵表征图像内容,设置权值函数避免由于AC系数分布熵相同、空间分布不同造成的误检和漏检情况。实验结果表明,该算法不需要完全解压缩、计算复杂度低,能较好体现图像的内容分布。
关键词:
JPEG图像检索,
离散余弦变换,
直流系数差向量,
交流系数分布熵
Abstract:
Aiming at the problem that Direct Current(DC) coefficient and Alternating Current(AC) coefficient express different image content information, this paper presents a JPEG image retrieval algorithm based on DCT coefficient. The difference vector of DC coefficient is constructed to describe image feature. The AC coefficient distribution entropy is presented according to the characteristic of the AC coefficients. The weight function for the entropy is presented to avoid the mistaken retrieval and losing retrieval. Experimental results show that the algorithm has no use for decompression and has lower complexity, and it can embody the content distribution of images well.
Key words:
JPEG image retrieval,
Discrete Cosine Transform(DCT),
Direct Current(DC) coefficient difference vector,
Alternating Current(AC) coefficient distribution entropy
中图分类号:
赵珊, 赵倩. 基于DCT系数的JPEG图像检索算法[J]. 计算机工程, 2010, 36(19): 190-192.
DIAO Shan, DIAO Qian. JPEG Image Retrieval Algorithm Based on DCT Coefficient[J]. Computer Engineering, 2010, 36(19): 190-192.