Analyzed the SIFT(Scale Invariant Feature Transform) and its Variants.

• SIFT
• PCA-SIFT
• GSIFT
• CSIFT
• SURF
• ASIFT

Summary

According to research work done by researchers ,

• SIFT and CSIFT perform the best under scale and rotation change.
• CSIFT improves SIFT under blur change and affine change, but not illumination change. 
• GSIFT performs the best under blur change and illumination change.
• ASIFT performs the best under affine change. 
• PCA-SIFT is always the second in different situations. 
• SURF performs the worst in different situations, but runs the fastest.