Process MPII Scale

process_scale.py

# avoid invisible keypoints whose value are <= 0
masked_keypoint_x = tf.boolean_mask(keypoint_x, keypoint_x > 0)
masked_keypoint_y = tf.boolean_mask(keypoint_y, keypoint_y > 0)

# find \left-most, top, bottom, and right-most keypoints
keypoint_xmin = tf.reduce_min(masked_keypoint_x)
keypoint_xmax = tf.reduce_max(masked_keypoint_x)
keypoint_ymin = tf.reduce_min(masked_keypoint_y)
keypoint_ymax = tf.reduce_max(masked_keypoint_y)

# add a padding according to human body height
xmin = keypoint_xmin - tf.cast(body_height * margin, dtype=tf.int32)
xmax = keypoint_xmax + tf.cast(body_height * margin, dtype=tf.int32)
ymin = keypoint_ymin - tf.cast(body_height * margin, dtype=tf.int32)
ymax = keypoint_ymax + tf.cast(body_height * margin, dtype=tf.int32)

# make sure the crop is valid
effective_xmin = xmin if xmin > 0 else 0
effective_ymin = ymin if ymin > 0 else 0
effective_xmax = xmax if xmax < img_width else img_width
effective_ymax = ymax if ymax < img_height else img_height
effective_height = effective_ymax - effective_ymin
effective_width = effective_xmax - effective_xmin