Three region texture spectrum descriptors,center-symmetric local binary pattern(CS-LBP),direction local binary pattern(D-LBP) and improved D-LBP(ID-LBP) are discussed in detail.Then,three rotation invariant texture descriptors,CS-LBP variance(CS-LBPV),D-LBP variance(D-LBPV) and improved D-LBP variance(ID-LBPV),are proposed in the paper to characterize the local contrast information into one-dimensional texture histogram.The three descriptors are tested and compared on three commonly used image d...