X-AnyLabeling系列：多类别单通道掩码转多边形坐标点

多类别单通道掩码转多边形坐标点

整体与掩码转多边形坐标点类似，主要是单类别单通道掩码改为多类别单通道掩码。

示例代码

import os
import cv2
import json
import numpy as np
from copy import deepcopydef get_image_size(image_file):image = cv2.imdecode(np.fromfile(image_file, dtype=np.uint8), 0)height, width = image.shape[:2]return width, heightdef reset(version):custom_data = dict(version=version,flags={},shapes=[],imagePath="",imageData=None,imageHeight=-1,imageWidth=-1,)return custom_datadef mask_to_polygon(mask, shape_dict, image_name,epsilon_factor,approx_len_threshold,point_interval_num=1
):contours, _ = cv2.findContours(mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)for contour in contours:epsilon = epsilon_factor * cv2.arcLength(contour, True)approx = cv2.approxPolyDP(contour, epsilon, True)if len(approx) < approx_len_threshold:print(f"{image_name}: \contour too small, len={len(approx)}")continuefor point in approx:x, y = point[0].tolist()shape_dict["points"].append([x, y])return shape_dictdef multiclass_mask_to_polygon(image_path, mask_path, json_path,mask_label_list, mask_color_list,shape_dict, epsilon_factor, approx_len_threshold,point_interval_num=1,
):# mask = cv2.imread(mask_path, cv2.IMREAD_GRAYSCALE)mask = cv2.imdecode(np.fromfile(mask_path, dtype=np.uint8), 0)image_name = os.path.basename(image_path)image_width, image_height = get_image_size(image_path)custom_data = reset("2.4.0")custom_data["imagePath"] = image_namecustom_data["imageHeight"] = image_heightcustom_data["imageWidth"] = image_widthfor label, color in zip(mask_label_list, mask_color_list):# 选择特定颜色的maskmask_label = cv2.inRange(mask, color, color)mask_label_shape_dict = deepcopy(shape_dict)mask_label_shape_dict["label"] = labelmask_label_shape_dict = mask_to_polygon(mask_label, mask_label_shape_dict, image_name,epsilon_factor,approx_len_threshold,point_interval_num,)custom_data["shapes"].append(mask_label_shape_dict)with open(json_path, "w", encoding="utf-8") as f:json.dump(custom_data, f, indent=2, ensure_ascii=False)if __name__ == '__main__':image_path = "./images/test.jpg"mask_path = "./masks/test.png"json_path = "./json/test.json"mask_label_list = ["label_1", "label_2"]mask_color_list = [255, 128]shape_dict = {"label": "","description": "","difficult": False,"points": [],"shape_type": "polygon",}multiclass_mask_to_polygon(image_path, mask_path, json_path,mask_label_list, mask_color_list,shape_dict, epsilon_factor=0.001, approx_len_threshold=5,point_interval_num=2,)