Mask R-CNN是一个实例分割算法，可以用来做目标检测、目标实例分割、目标关键点检测。
下面测试它的onnx版本。

onnx的model和相关资料在此处下载。

测试图片：

图片的预处理部分，参考中用了Image来读图片，这里改成了opencv版本。

import numpy as np
import cv2
import onnxruntime
from utils import _COLORS  #自己定义一些mask颜色

#这里把Image版本改成了opencv版本
def preprocess(image):
    # Resize
    ratio = 800.0 / min(image.shape[0], image.shape[1])
    image = cv2.resize(image, (int(ratio * image.shape[1]), int(ratio * image.shape[0])))

    # Convert to BGR
    image = np.array(image)[:, :, [2, 1, 0]].astype('float32')

    # HWC -> CHW
    image = np.transpose(image, [2, 0, 1])

    # Normalize
    mean_vec = np.array([102.9801, 115.9465, 122.7717])
    for i in range(image.shape[0]):
        image[i, :, :] = image[i, :, :] - mean_vec[i]

    # Pad to be divisible of 32
    import math
    padded_h = int(math.ceil(image.shape[1] / 32) * 32)
    padded_w = int(math.ceil(image.shape[2] / 32) * 32)

    padded_image = np.zeros((3, padded_h, padded_w), dtype=np.float32)
    padded_image[:, :image.shape[1], :image.shape[2]] = image
    image = padded_image

    return image

后处理部分。
原版是画轮廓，这里改成了画mask区域。

def display_objdetect_image(image, boxes, labels, scores, masks, score_threshold=0.7):
    # Resize boxes
    ratio = 800.0 / min(image.shape[0], image.shape[1])
    boxes /= ratio

    image = np.array(image)

    for mask, box, label, score in zip(masks, boxes, labels, scores):
        # Showing boxes with score > 0.7
        if score <= score_threshold:
            continue

        # Finding contour based on mask
        #mask:(1,28,28)
        mask = mask[0, :, :, None]  #(28,28,1)
        int_box = [int(i) for i in box]
        mask = cv2.resize(mask, (int_box[2]-int_box[0]+1,int_box[3]-int_box[1]+1)) #box区域大小
        mask = mask > 0.5
        im_mask = np.zeros((image.shape[0], image.shape[1]), dtype=np.uint8) #image大小的全0mask
        x_0 = max(int_box[0], 0)
        x_1 = min(int_box[2] + 1, image.shape[1])
        y_0 = max(int_box[1], 0)
        y_1 = min(int_box[3] + 1, image.shape[0])
        mask_y_0 = max(y_0 - box[1], 0)
        mask_y_1 = max(0, mask_y_0 + y_1 - y_0)
        mask_x_0 = max(x_0 - box[0], 0)
        mask_x_1 = max(0, mask_x_0 + x_1 - x_0)
     
        im_mask[y_0:y_1, x_0:x_1] = mask[  #box区域填上mask，（480,640,1)
            mask_y_0 : mask_y_1, mask_x_0 : mask_x_1
        ]

        im_mask = im_mask[:, :, None] #(480,640,1)
        mask3 = image.copy()  #填上颜色的mask

        color = (_COLORS[label]*255).astype(np.uint8).tolist()
        mask3[im_mask[:,:,0]>0] = color
        image = cv2.addWeighted(image, 0.5, mask3, 0.5, 0)
		
        text = "{}:{:.1f}%".format(classes[label], score * 100)
        txt_color = (0, 0, 0) if np.mean(_COLORS[label]) > 0.5 else (255, 255, 255)
        font = cv2.FONT_HERSHEY_SIMPLEX
        txt_size = cv2.getTextSize(text, font, 0.5, 2)[0]
        #画box框
        cv2.rectangle(image, (x_0, y_0), (x_1, y_1), color, 1)
        #标签区域框
        cv2.rectangle(
            image,
            (x_0, y_0 - txt_size[1] - 1),
            (x_0 + txt_size[0] + txt_size[1], y_0 - 1),
            color,
            -1,
        )
        #填上标签
        cv2.putText(image, text, (x_0, y_0 - 1), font, 0.5, txt_color, thickness=1)
    cv2.imshow("image", image)
    cv2.waitKey(0)

ONNX推理部分（main函数）

if __name__ == '__main__':
    img = cv2.imread('./demo.jpg')
    #前处理
    img_data = preprocess(img)

    #onnx process
    session = onnxruntime.InferenceSession("./MaskRCNN-12.onnx",
                                           providers=['CUDAExecutionProvider',
                                                      'CPUExecutionProvider'])
    model_inputs = session.get_inputs()
    input_names = [model_inputs[i].name for i in range(len(model_inputs))]

    input_shape = model_inputs[0].shape
    input_height = input_shape[1]
    input_width = input_shape[2]
    model_outputs = session.get_outputs()
    output_names = [model_outputs[i].name for i in range(len(model_outputs))]
    # time1 = time.time()
    outputs = session.run(output_names, {input_names[0]: img_data})
    # time2 = time.time()
    boxes = outputs[0]
    labels = outputs[1]
    scores = outputs[2]
    masks = outputs[3]
  	#后处理
    display_objdetect_image(img, boxes, labels, scores, masks)