Artificial intelligence GC–LSTM model HKPolyU-DB K-nearest neighbors Krawtchouk polynomials Marr wavelets RANSAC SDUMLA-HMT-DB Social aspects Tchebichef polynomials Technology: general issues action recognition active learning armature artificial image generation artificial intelligence autoencoders bag of deep features binarized statistical image features biometrics body orientation bounding box regression brain computer interface building extraction camera position channel interaction character recognition common spatial patterns computer vision continuous wavelet transform