region.py 文件源码

def _process_input(self, x):
        """Apply logistic and softmax activations to input tensor
        """
        logistic_activate = lambda x: 1.0/(1.0 + K.exp(-x))

        (batch, w, h, channels) = x.get_shape()
        x_temp = K.permute_dimensions(x, (3, 0, 1, 2))
        x_t = []
        for i in range(self.num):
            k = self._entry_index(i, 0)
            x_t.extend([
                logistic_activate(K.gather(x_temp, (k, k + 1))), # 0
                K.gather(x_temp, (k + 2, k + 3))])
            if self.background:
                x_t.append(K.gather(x_temp, (k + 4,)))
            else:
                x_t.append(logistic_activate(K.gather(x_temp, (k + 4,))))

            x_t.append(
                softmax(
                    K.gather(x_temp, tuple(range(k + 5, k + self.coords + self.classes + 1))),
                    axis=0))
        x_t = K.concatenate(x_t, axis=0)
        return K.permute_dimensions(x_t, (1, 2, 3, 0))