'''Local ternary patterns''' (LTP) isare an extension of the [[Local binary patterns]] introduced by (LBP).<ref>Xiaoyang Tan and Bill Triggs, Enhanced Local Texture Feature Sets for Face Recognition Under Difficult Lighting Conditions, IEEE Transactions on Image Processing, 19(6), pp. 1635-1650, 2010</ref>. Unlike LBP, it does not threshold the pixels into 0 and 1, rather it uses a threshold constant to threshold pixels into three values. Considering k as the threshold constant, c as the value of the center pixel, a neighboring pixel p, the result of threshold is:<br />
