mmpose/projects/rtmpose/examples/onnxruntime/main.py

# Copyright (c) OpenMMLab. All rights reserved.
import argparse
import time
from typing import List, Tuple

import cv2
import loguru
import numpy as np
import onnxruntime as ort

logger = loguru.logger


def parse_args():
    parser = argparse.ArgumentParser(
        description='RTMPose ONNX inference demo.')
    parser.add_argument('onnx_file', help='ONNX file path')
    parser.add_argument('image_file', help='Input image file path')
    parser.add_argument(
        '--device', help='device type for inference', default='cpu')
    parser.add_argument(
        '--save-path',
        help='path to save the output image',
        default='output.jpg')
    args = parser.parse_args()
    return args


def preprocess(
    img: np.ndarray, input_size: Tuple[int, int] = (192, 256)
) -> Tuple[np.ndarray, np.ndarray, np.ndarray]:
    """Do preprocessing for RTMPose model inference.

    Args:
        img (np.ndarray): Input image in shape.
        input_size (tuple): Input image size in shape (w, h).

    Returns:
        tuple:
        - resized_img (np.ndarray): Preprocessed image.
        - center (np.ndarray): Center of image.
        - scale (np.ndarray): Scale of image.
    """
    # get shape of image
    img_shape = img.shape[:2]
    bbox = np.array([0, 0, img_shape[1], img_shape[0]])

    # get center and scale
    center, scale = bbox_xyxy2cs(bbox, padding=1.25)

    # do affine transformation
    resized_img, scale = top_down_affine(input_size, scale, center, img)

    # normalize image
    mean = np.array([123.675, 116.28, 103.53])
    std = np.array([58.395, 57.12, 57.375])
    resized_img = (resized_img - mean) / std

    return resized_img, center, scale


def build_session(onnx_file: str, device: str = 'cpu') -> ort.InferenceSession:
    """Build onnxruntime session.

    Args:
        onnx_file (str): ONNX file path.
        device (str): Device type for inference.

    Returns:
        sess (ort.InferenceSession): ONNXRuntime session.
    """
    providers = ['CPUExecutionProvider'
                 ] if device == 'cpu' else ['CUDAExecutionProvider']
    sess = ort.InferenceSession(path_or_bytes=onnx_file, providers=providers)

    return sess


def inference(sess: ort.InferenceSession, img: np.ndarray) -> np.ndarray:
    """Inference RTMPose model.

    Args:
        sess (ort.InferenceSession): ONNXRuntime session.
        img (np.ndarray): Input image in shape.

    Returns:
        outputs (np.ndarray): Output of RTMPose model.
    """
    # build input
    input = [img.transpose(2, 0, 1)]

    # build output
    sess_input = {sess.get_inputs()[0].name: input}
    sess_output = []
    for out in sess.get_outputs():
        sess_output.append(out.name)

    # run model
    outputs = sess.run(sess_output, sess_input)

    return outputs


def postprocess(outputs: List[np.ndarray],
                model_input_size: Tuple[int, int],
                center: Tuple[int, int],
                scale: Tuple[int, int],
                simcc_split_ratio: float = 2.0
                ) -> Tuple[np.ndarray, np.ndarray]:
    """Postprocess for RTMPose model output.

    Args:
        outputs (np.ndarray): Output of RTMPose model.
        model_input_size (tuple): RTMPose model Input image size.
        center (tuple): Center of bbox in shape (x, y).
        scale (tuple): Scale of bbox in shape (w, h).
        simcc_split_ratio (float): Split ratio of simcc.

    Returns:
        tuple:
        - keypoints (np.ndarray): Rescaled keypoints.
        - scores (np.ndarray): Model predict scores.
    """
    # use simcc to decode
    simcc_x, simcc_y = outputs
    keypoints, scores = decode(simcc_x, simcc_y, simcc_split_ratio)

    # rescale keypoints
    keypoints = keypoints / model_input_size * scale + center - scale / 2

    return keypoints, scores


def visualize(img: np.ndarray,
              keypoints: np.ndarray,
              scores: np.ndarray,
              filename: str = 'output.jpg',
              thr=0.3) -> np.ndarray:
    """Visualize the keypoints and skeleton on image.

    Args:
        img (np.ndarray): Input image in shape.
        keypoints (np.ndarray): Keypoints in image.
        scores (np.ndarray): Model predict scores.
        thr (float): Threshold for visualize.

    Returns:
        img (np.ndarray): Visualized image.
    """
    # default color
    skeleton = [(15, 13), (13, 11), (16, 14), (14, 12), (11, 12), (5, 11),
                (6, 12), (5, 6), (5, 7), (6, 8), (7, 9), (8, 10), (1, 2),
                (0, 1), (0, 2), (1, 3), (2, 4), (3, 5), (4, 6), (15, 17),
                (15, 18), (15, 19), (16, 20), (16, 21), (16, 22), (91, 92),
                (92, 93), (93, 94), (94, 95), (91, 96), (96, 97), (97, 98),
                (98, 99), (91, 100), (100, 101), (101, 102), (102, 103),
                (91, 104), (104, 105), (105, 106), (106, 107), (91, 108),
                (108, 109), (109, 110), (110, 111), (112, 113), (113, 114),
                (114, 115), (115, 116), (112, 117), (117, 118), (118, 119),
                (119, 120), (112, 121), (121, 122), (122, 123), (123, 124),
                (112, 125), (125, 126), (126, 127), (127, 128), (112, 129),
                (129, 130), (130, 131), (131, 132)]
    palette = [[51, 153, 255], [0, 255, 0], [255, 128, 0], [255, 255, 255],
               [255, 153, 255], [102, 178, 255], [255, 51, 51]]
    link_color = [
        1, 1, 2, 2, 0, 0, 0, 0, 1, 2, 1, 2, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2,
        2, 2, 2, 2, 2, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 1, 1, 1, 1, 2, 2, 2,
        2, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 1, 1, 1, 1
    ]
    point_color = [
        0, 0, 0, 0, 0, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 2, 2, 2, 2, 2, 2, 3,
        3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
        3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
        3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2,
        4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 1, 1, 1, 1, 3, 2, 2, 2, 2, 4, 4, 4,
        4, 5, 5, 5, 5, 6, 6, 6, 6, 1, 1, 1, 1
    ]

    # draw keypoints and skeleton
    for kpts, score in zip(keypoints, scores):
        for kpt, color in zip(kpts, point_color):
            cv2.circle(img, tuple(kpt.astype(np.int32)), 1, palette[color], 1,
                       cv2.LINE_AA)
        for (u, v), color in zip(skeleton, link_color):
            if score[u] > thr and score[v] > thr:
                cv2.line(img, tuple(kpts[u].astype(np.int32)),
                         tuple(kpts[v].astype(np.int32)), palette[color], 2,
                         cv2.LINE_AA)

    # save to local
    cv2.imwrite(filename, img)

    return img


def bbox_xyxy2cs(bbox: np.ndarray,
                 padding: float = 1.) -> Tuple[np.ndarray, np.ndarray]:
    """Transform the bbox format from (x,y,w,h) into (center, scale)

    Args:
        bbox (ndarray): Bounding box(es) in shape (4,) or (n, 4), formatted
            as (left, top, right, bottom)
        padding (float): BBox padding factor that will be multilied to scale.
            Default: 1.0

    Returns:
        tuple: A tuple containing center and scale.
        - np.ndarray[float32]: Center (x, y) of the bbox in shape (2,) or
            (n, 2)
        - np.ndarray[float32]: Scale (w, h) of the bbox in shape (2,) or
            (n, 2)
    """
    # convert single bbox from (4, ) to (1, 4)
    dim = bbox.ndim
    if dim == 1:
        bbox = bbox[None, :]

    # get bbox center and scale
    x1, y1, x2, y2 = np.hsplit(bbox, [1, 2, 3])
    center = np.hstack([x1 + x2, y1 + y2]) * 0.5
    scale = np.hstack([x2 - x1, y2 - y1]) * padding

    if dim == 1:
        center = center[0]
        scale = scale[0]

    return center, scale


def _fix_aspect_ratio(bbox_scale: np.ndarray,
                      aspect_ratio: float) -> np.ndarray:
    """Extend the scale to match the given aspect ratio.

    Args:
        scale (np.ndarray): The image scale (w, h) in shape (2, )
        aspect_ratio (float): The ratio of ``w/h``

    Returns:
        np.ndarray: The reshaped image scale in (2, )
    """
    w, h = np.hsplit(bbox_scale, [1])
    bbox_scale = np.where(w > h * aspect_ratio,
                          np.hstack([w, w / aspect_ratio]),
                          np.hstack([h * aspect_ratio, h]))
    return bbox_scale


def _rotate_point(pt: np.ndarray, angle_rad: float) -> np.ndarray:
    """Rotate a point by an angle.

    Args:
        pt (np.ndarray): 2D point coordinates (x, y) in shape (2, )
        angle_rad (float): rotation angle in radian

    Returns:
        np.ndarray: Rotated point in shape (2, )
    """
    sn, cs = np.sin(angle_rad), np.cos(angle_rad)
    rot_mat = np.array([[cs, -sn], [sn, cs]])
    return rot_mat @ pt


def _get_3rd_point(a: np.ndarray, b: np.ndarray) -> np.ndarray:
    """To calculate the affine matrix, three pairs of points are required. This
    function is used to get the 3rd point, given 2D points a & b.

    The 3rd point is defined by rotating vector `a - b` by 90 degrees
    anticlockwise, using b as the rotation center.

    Args:
        a (np.ndarray): The 1st point (x,y) in shape (2, )
        b (np.ndarray): The 2nd point (x,y) in shape (2, )

    Returns:
        np.ndarray: The 3rd point.
    """
    direction = a - b
    c = b + np.r_[-direction[1], direction[0]]
    return c


def get_warp_matrix(center: np.ndarray,
                    scale: np.ndarray,
                    rot: float,
                    output_size: Tuple[int, int],
                    shift: Tuple[float, float] = (0., 0.),
                    inv: bool = False) -> np.ndarray:
    """Calculate the affine transformation matrix that can warp the bbox area
    in the input image to the output size.

    Args:
        center (np.ndarray[2, ]): Center of the bounding box (x, y).
        scale (np.ndarray[2, ]): Scale of the bounding box
            wrt [width, height].
        rot (float): Rotation angle (degree).
        output_size (np.ndarray[2, ] | list(2,)): Size of the
            destination heatmaps.
        shift (0-100%): Shift translation ratio wrt the width/height.
            Default (0., 0.).
        inv (bool): Option to inverse the affine transform direction.
            (inv=False: src->dst or inv=True: dst->src)

    Returns:
        np.ndarray: A 2x3 transformation matrix
    """
    shift = np.array(shift)
    src_w = scale[0]
    dst_w = output_size[0]
    dst_h = output_size[1]

    # compute transformation matrix
    rot_rad = np.deg2rad(rot)
    src_dir = _rotate_point(np.array([0., src_w * -0.5]), rot_rad)
    dst_dir = np.array([0., dst_w * -0.5])

    # get four corners of the src rectangle in the original image
    src = np.zeros((3, 2), dtype=np.float32)
    src[0, :] = center + scale * shift
    src[1, :] = center + src_dir + scale * shift
    src[2, :] = _get_3rd_point(src[0, :], src[1, :])

    # get four corners of the dst rectangle in the input image
    dst = np.zeros((3, 2), dtype=np.float32)
    dst[0, :] = [dst_w * 0.5, dst_h * 0.5]
    dst[1, :] = np.array([dst_w * 0.5, dst_h * 0.5]) + dst_dir
    dst[2, :] = _get_3rd_point(dst[0, :], dst[1, :])

    if inv:
        warp_mat = cv2.getAffineTransform(np.float32(dst), np.float32(src))
    else:
        warp_mat = cv2.getAffineTransform(np.float32(src), np.float32(dst))

    return warp_mat


def top_down_affine(input_size: dict, bbox_scale: dict, bbox_center: dict,
                    img: np.ndarray) -> Tuple[np.ndarray, np.ndarray]:
    """Get the bbox image as the model input by affine transform.

    Args:
        input_size (dict): The input size of the model.
        bbox_scale (dict): The bbox scale of the img.
        bbox_center (dict): The bbox center of the img.
        img (np.ndarray): The original image.

    Returns:
        tuple: A tuple containing center and scale.
        - np.ndarray[float32]: img after affine transform.
        - np.ndarray[float32]: bbox scale after affine transform.
    """
    w, h = input_size
    warp_size = (int(w), int(h))

    # reshape bbox to fixed aspect ratio
    bbox_scale = _fix_aspect_ratio(bbox_scale, aspect_ratio=w / h)

    # get the affine matrix
    center = bbox_center
    scale = bbox_scale
    rot = 0
    warp_mat = get_warp_matrix(center, scale, rot, output_size=(w, h))

    # do affine transform
    img = cv2.warpAffine(img, warp_mat, warp_size, flags=cv2.INTER_LINEAR)

    return img, bbox_scale


def get_simcc_maximum(simcc_x: np.ndarray,
                      simcc_y: np.ndarray) -> Tuple[np.ndarray, np.ndarray]:
    """Get maximum response location and value from simcc representations.

    Note:
        instance number: N
        num_keypoints: K
        heatmap height: H
        heatmap width: W

    Args:
        simcc_x (np.ndarray): x-axis SimCC in shape (K, Wx) or (N, K, Wx)
        simcc_y (np.ndarray): y-axis SimCC in shape (K, Wy) or (N, K, Wy)

    Returns:
        tuple:
        - locs (np.ndarray): locations of maximum heatmap responses in shape
            (K, 2) or (N, K, 2)
        - vals (np.ndarray): values of maximum heatmap responses in shape
            (K,) or (N, K)
    """
    N, K, Wx = simcc_x.shape
    simcc_x = simcc_x.reshape(N * K, -1)
    simcc_y = simcc_y.reshape(N * K, -1)

    # get maximum value locations
    x_locs = np.argmax(simcc_x, axis=1)
    y_locs = np.argmax(simcc_y, axis=1)
    locs = np.stack((x_locs, y_locs), axis=-1).astype(np.float32)
    max_val_x = np.amax(simcc_x, axis=1)
    max_val_y = np.amax(simcc_y, axis=1)

    # get maximum value across x and y axis
    mask = max_val_x > max_val_y
    max_val_x[mask] = max_val_y[mask]
    vals = max_val_x
    locs[vals <= 0.] = -1

    # reshape
    locs = locs.reshape(N, K, 2)
    vals = vals.reshape(N, K)

    return locs, vals


def decode(simcc_x: np.ndarray, simcc_y: np.ndarray,
           simcc_split_ratio) -> Tuple[np.ndarray, np.ndarray]:
    """Modulate simcc distribution with Gaussian.

    Args:
        simcc_x (np.ndarray[K, Wx]): model predicted simcc in x.
        simcc_y (np.ndarray[K, Wy]): model predicted simcc in y.
        simcc_split_ratio (int): The split ratio of simcc.

    Returns:
        tuple: A tuple containing center and scale.
        - np.ndarray[float32]: keypoints in shape (K, 2) or (n, K, 2)
        - np.ndarray[float32]: scores in shape (K,) or (n, K)
    """
    keypoints, scores = get_simcc_maximum(simcc_x, simcc_y)
    keypoints /= simcc_split_ratio

    return keypoints, scores


def main():
    args = parse_args()
    logger.info('Start running model on RTMPose...')

    # read image from file
    logger.info('1. Read image from {}...'.format(args.image_file))
    img = cv2.imread(args.image_file)

    # build onnx model
    logger.info('2. Build onnx model from {}...'.format(args.onnx_file))
    sess = build_session(args.onnx_file, args.device)
    h, w = sess.get_inputs()[0].shape[2:]
    model_input_size = (w, h)

    # preprocessing
    logger.info('3. Preprocess image...')
    resized_img, center, scale = preprocess(img, model_input_size)

    # inference
    logger.info('4. Inference...')
    start_time = time.time()
    outputs = inference(sess, resized_img)
    end_time = time.time()
    logger.info('4. Inference done, time cost: {:.4f}s'.format(end_time -
                                                               start_time))

    # postprocessing
    logger.info('5. Postprocess...')
    keypoints, scores = postprocess(outputs, model_input_size, center, scale)

    # visualize inference result
    logger.info('6. Visualize inference result...')
    visualize(img, keypoints, scores, args.save_path)

    logger.info('Done...')


if __name__ == '__main__':
    main()