I am currently reading the paper arXiv:1810.03787. The authors claim that QCNN uses only $O(\log N)$ variational parameters, where $N$ is the number of qubits. However, I am having difficulty understanding how to count the number of variational parameters for an input size of $N$ qubits.
Furthermore, in the case of Convolutional Neural Networks (CNNs), to my knowledge, the number of parameters is determined by the structure of the CNN rather than the size of the input. Could you help me revise this for clarity?