model.py 文件源码

def get_tiled_anchors_for_shape(self, width, height):
        """ creates/tiles anchors for a width x height image/feature map,
            producing coordinates from [0, width) and [0, height) for the
            resulting bounding boxes, according to the feature stride
            of the last conv layer """
        anchors = tf.expand_dims(self.anchors, axis=0)
        feat_height = tf.cast(tf.ceil(height/self.feat_stride), tf.int32)
        feat_width = tf.cast(tf.ceil(width/self.feat_stride), tf.int32)
        anchor_shape = [feat_height * feat_width, 1, 1]
        anchors = tf.tile(anchors, tf.stack(anchor_shape))

        x = tf.range(0.0, feat_width * self.feat_stride, self.feat_stride)
        y = tf.range(0.0, feat_height * self.feat_stride, self.feat_stride)

        X, Y = tf.meshgrid(x, y)
        X = tf.expand_dims(X, 2)
        Y = tf.expand_dims(Y, 2)

        shift = tf.reshape(tf.concat([Y, X, tf.zeros_like(X), tf.zeros_like(X)], 2), [-1, 1, 4])

        shift = tf.tile(shift, [1, self.num_anchors, 1])

        anchors = tf.cast(anchors, tf.float32) + shift
        return tf.reshape(anchors, [-1, 4])