sift

代码说明：

  1 SIFT 发展历程 SIFT算法由D.G.Lowe 1999年提出，2004年完善总结。后来Y.Ke将其描述子部分用PCA代替直方图的方式，对其进行改进。 2 SIFT 主要思想 SIFT算法是一种提取局部特征的算法，在尺度空间寻找极值点，提取位置，尺度，旋转不变量。 3 SIFT算法的主要特点： a) SIFT特征是图像的局部特征，其对旋转、尺度缩放、亮度变化保持不变性，对视角变化、仿射变换、噪声也保持一定程度的稳定性。 b) 独特性(Distinctiveness)好，信息量丰富，适用于在海量特征数据库中进行快速、准确的匹配[23]。 c) 多量性，即使少数的几个物体也可以产生大量SIFT特征向量。 d) 高速性，经优化的SIFT匹配算法甚至可以达到实时的要求。 e) 可扩展性，可以很方便的与其他形式的特征向量进行联合。 4 SIFT算法步骤： 1） 检测尺度空间极值点 2） 精确定位极值点 3） 为每个关键点指定方向参数 4） 关键点描述子的生成 本包内容为sift算法matlab源码(1 SIFT course of development SIFT algorithm by DGLowe in 1999, the perfect summary of 2004. Later Y.Ke its description of the sub-part of the histogram with PCA instead of its improvement. 2 the SIFT main idea The SIFT algorithm is an algorithm to extract local features in scale space to find the extreme point of the extraction location, scale, rotation invariant. 3 the main features of the SIFT algorithm: a) SIFT feature is the local characteristics of the image, zoom, rotate, scale, brightness change to maintain invariance, the perspective changes, affine transformation, the noise also maintain a certain degree of stability. b) unique (Distinctiveness), informative, and mass characteristics database for fast, accurate matching [23]. c) large amounts, even if a handful of objects can also produce a large number of SIFT feature vectors. d) high-speed and optimized SIFT matching algorithm can even achieve real-time requirements. e) The scalability can be very convenient fe)

文件列表：

sift
....\data
....\....\box.pgm,72310,2008-04-17
....\....\box.sift,233055,2008-04-17
....\....\circle.pgm,10060,2008-04-17
....\....\circle.sift,1362,2008-04-17





....\....\nest2.bmp,17462,2008-04-17
....\....\vessel-1.pgm,337980,2008-04-17
....\....\vessel-2.pgm,337980,2008-04-17
....\diffss.m,2797,2008-04-17
....\doc
....\...\bibliography.bib,246,2008-04-17
....\...\figures
....\...\.......\sift-descriptor-AI.bb,550,2008-04-17
....\...\.......\sift-descriptor-AI.pdf,475918,2008-04-17
....\...\.......\sift-descriptor-SAVED.tex,3275,2008-04-17
....\...\.......\sift-descriptor.aux,8,2008-04-17
....\...\.......\sift-descriptor.log,13430,2008-04-17
....\...\.......\sift-descriptor.pdf,443880,2008-04-17
....\...\.......\sift-descriptor.tex,3275,2008-04-17
....\...\.......\sift-descriptor.wrm,13,2008-04-17
....\...\.......\warmread.sty,48557,2008-04-17
....\...\sift.bbl,239,2008-04-17
....\...\sift.tex,22461,2008-04-17
....\...\visionlab.sty,6174,2008-04-17
....\gaussianss.m,7920,2008-04-17
....\imreadbw.m,2359,2008-04-17
....\imsmooth.c,3960,2008-04-17
....\imsmooth.dll,8192,2012-05-24
....\htm" target=_blank>LICENSE,1990,2008-04-17
....\Makefile,4345,2008-04-17
....\mexutils.c,2178,2008-04-17
....\plotmatches.m,10001,2008-04-17
....\plotsiftdescriptor.m,5466,2008-04-17
....\plotsiftframe.m,5222,2008-04-17
....\plotss.m,2734,2008-04-17
....\htm" target=_blank>README,2600,2008-04-17
....\sift.m,10029,2008-04-17
....\siftdescriptor.c,16452,2008-04-17
....\siftdescriptor.dll,14336,2012-05-24
....\siftdescriptor.m,4047,2008-04-17
....\siftlocalmax.c,8784,2008-04-17
....\siftlocalmax.dll,9216,2012-05-24
....\siftlocalmax.m,1637,2008-04-17
....\siftmatch.c,10420,2008-04-17
....\siftmatch.dll,10240,2012-05-24
....\siftmatch.m,2925,2008-04-17
....\siftormx.c,8580,2008-04-17
....\siftormx.dll,11264,2012-05-24
....\siftread.m,3575,2008-04-17
....\siftrefinemx.c,10019,2008-04-17
....\siftrefinemx.dll,11264,2012-05-24
....\siftrefinemx.m,3109,2008-04-17
....\sift_compile.m,963,2008-04-17
....\sift_demo.m,3435,2008-04-17
....\sift_demo2.m,4460,2008-04-17
....\sift_demo3.m,1744,2008-04-17
....\sift_demo4.m,1409,2008-04-17
....\sift_demo5.m,387,2008-04-17
....\sift_demo6.m,957,2008-04-17
....\sift_gendoc.css,2560,2008-04-17
....\sift_overview.m,1170,2008-04-17
....\tightsubplot.m,5136,2008-04-17
....\TIMESTAMP,63,2008-04-17
....\VERSION,7,2008-04-17