“…These data-independent method produce more generalized encodings, but tend to need long codes because they are randomly selected and do not con- sider the distribution of the data. In contrast, datadependent methods that consider the neighbor structure of the data points are able to obtain more compact binary codes (e.g., Restricted Boltzmann Machines (RBMs) [7], spectral hashing [5], PCA hashing [18], spherical hashing [11], kmeans-hashing [13], semi-supervised hashing [19,20], and iterative quantization [21,22]). …”