将mask图像转换成coco形式(包含bbox)

最近在医学图像上visual grounding的实验,由于大多息肉的任务都是分割,我之前收集的数据集也是无监督数据集or分割数据集,因此萌发了将mask转成bounding box标签的念头,来扩充目标检测数据集。

借鉴以下博客,但是我的数据在他的代码上有问题,所以做了一些修改。数据集:息肉二分类分割数据集,一张图中可能包含多个息肉。【coco】掩膜mask影像转coco格式txt(含python代码)_实例分割 将mask转化为txt-CSDN博客

coco数据集的格式

一张图片可以对应多个annotations,所以id是累加的,但注意images中的id要与annotations中的image_id一致

{
"info": [
{"year": "2023","version": "1","contributor": "bulibuli","url": "","date_created": "2023-01-17"
}
],
"lisence": [
{"id": 1,"url": "https://creativecommons.org/licenses/by/4.0/","name": "CC BY 4.0"
}
],
"categories": [
{"supercategory": "polyp","id": 1,"name": "polyp"
}
],
"images": [
{"height": 500,"width": 574,"id": 1,"file_name": "CVC-300151.png"
},
...
"annotations": [
{"segmentation": [[446,517,447,517,448,517,449,517,450,517,451,517,452,517,453,517,454,517,455,517]],"area": 46450.0,"iscrowd": 0,"image_id": 1,"bbox": [776,663,324,246],"category_id": 1,"id": 1
},
.....
]
}

路径设置

图像和mask的文件名必须一一对应,一模一样。

# mask图像路径
block_mask_path = 'your path'
block_mask_image_files = sorted(os.listdir(block_mask_path))# coco json保存的位置
jsonPath = "your path/label.json"
annCount = 1
imageCount = 1
# 原图像的路径, 原图像和mask图像的名称是一致的。
path = "your path"
rgb_image_files = sorted(os.listdir(path))
if block_mask_image_files!=rgb_image_files: print("error")

写入基本信息和lisence

with io.open(jsonPath, 'w', encoding='utf8') as output:# 那就全部写在一个文件夹好了output.write(unicode('{\n'))# 基本信息output.write(unicode('"info": [\n'))output.write(unicode('{\n'))info={"year": "2023","version": "1","contributor": "bulibuli","url": "","date_created": "2023-01-17"}str_ = json.dumps(info, indent=4)str_ = str_[1:-1]if len(str_) > 0:output.write(unicode(str_))output.write(unicode('}\n'))output.write(unicode('],\n'))#lisenceoutput.write(unicode('"lisence": [\n'))output.write(unicode('{\n'))info={"id": 1,"url": "https://creativecommons.org/licenses/by/4.0/","name": "CC BY 4.0"}str_ = json.dumps(info, indent=4)str_ = str_[1:-1]if len(str_) > 0:output.write(unicode(str_))output.write(unicode('}\n'))output.write(unicode('],\n'))

写入类别

这里只有一个类别:息肉,因此直接写入即可,如果有多个类别,也可以往里面添加,请自助修改,但是一般多分类的数据集应该不会只有一个mask吧。

# categoryoutput.write(unicode('"categories": [\n'))output.write(unicode('{\n'))categories = {"supercategory": "polyp","id": 1,"name": "polyp"}str_ = json.dumps(categories, indent=4)str_ = str_[1:-1]if len(str_) > 0:output.write(unicode(str_))output.write(unicode('}\n'))output.write(unicode('],\n'))

写入图像信息

需要用cv2读入图像,并获取宽高。

# images    output.write(unicode('"images": [\n'))for image in rgb_image_files:if os.path.exists(os.path.join(block_mask_path, image)):output.write(unicode('{'))block_im = cv2.imread(os.path.join(path, image))h,w,_=block_im.shapeannotation = {"height": h,"width": w,"id": imageCount,"file_name": image}str_ = json.dumps(annotation, indent=4)str_ = str_[1:-1]if len(str_) > 0:output.write(unicode(str_))imageCount = imageCount + 1if (image == rgb_image_files[-1]):output.write(unicode('}\n'))else:output.write(unicode('},\n'))output.write(unicode('],\n'))

写入标签信息

读取二值图像并转成array,获取该图像的annotations,传入image_id,类别id。对于每个annotation写入文件。

# 写annotationsoutput.write(unicode('"annotations": [\n'))for i in range(len(block_mask_image_files)):if os.path.exists(os.path.join(path, block_mask_image_files[i])):block_image = block_mask_image_files[i]# print(block_image)# 读取二值图像block_im = cv2.imread(os.path.join(block_mask_path, block_image), 0)_, block_im = cv2.threshold(block_im, 100, 1, cv2.THRESH_BINARY)if not block_im is None:block_im = np.array(block_im, dtype=object).astype(np.uint8)block_anno = maskToanno(block_im, annCount, 1)# print(block_image,len(block_anno))for b in block_anno:str_block = json.dumps(b, indent=4)str_block = str_block[1:-1]if len(str_block) > 0:output.write(unicode('{\n'))output.write(unicode(str_block))if (block_image == rgb_image_files[-1] and b == block_anno[-1]):output.write(unicode('}\n'))else:output.write(unicode('},\n'))annCount = annCount + 1else:print(block_image)

masktoanno函数

首先利用cv2.findContours函数,找到所有的轮廓,这里只取外轮廓,因为我们的分割mask是实心的。该函数有两个输出,我们取第一个输出,是一个列表存储了所有轮廓,如果该列表的长度为0,则说明, mask图像是全黑的,该图像中没有息肉。

然后对于每一个轮廓,如果长度小于3,则说明该轮廓构不成一个面,因此该轮廓作废。其余的轮廓我们直接采取cv2.contourArea函数获取mask的面积,然后通过cv2.boundingRect直接将轮廓转成bounding box,添加进annotation,加入文件。

global segmentation_id
segmentation_id = 1
# annotations部分的实现
def maskToanno(ground_truth_binary_mask, ann_count, category_id):contours, _ = cv2.findContours(ground_truth_binary_mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)  # 根据二值图找轮廓annotations = [] #一幅图片所有的annotatons# print(len(contours),contours)global segmentation_idif(len(contours)==0):print("0")# 对每个实例进行处理for i,contour in enumerate(contours):if(len(contour)<3):print("The contour does not constitute an area")continueground_truth_area = cv2.contourArea(contour)x, y, w, h = cv2.boundingRect(contour)annotation = {"segmentation": [],"area": ground_truth_area,"iscrowd": 0,"image_id": ann_count,"bbox": [x,y,w,h],"category_id": category_id,"id": segmentation_id}# 求segmentation部分contour = np.flip(contour, axis=0)segmentation = contour.ravel().tolist()annotation["segmentation"].append(segmentation)annotations.append(annotation)segmentation_id = segmentation_id + 1return annotations

总代码

目前生成的json没有问题,但是还没训练看效果,效果过几天再更新。

import json
import numpy as np
from pycocotools import mask
import cv2
import os
import sysif sys.version_info[0] >= 3:unicode = strimport io
# 实例的id,每个图像有多个物体每个物体的唯一id
global segmentation_id
segmentation_id = 1
# annotations部分的实现
def maskToanno(ground_truth_binary_mask, ann_count, category_id):contours, _ = cv2.findContours(ground_truth_binary_mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)  # 根据二值图找轮廓annotations = [] #一幅图片所有的annotatons# print(len(contours),contours)global segmentation_idif(len(contours)==0):print("0")# 对每个实例进行处理for i,contour in enumerate(contours):if(len(contour)<3):print("The contour does not constitute an area")continueground_truth_area = cv2.contourArea(contour)x, y, w, h = cv2.boundingRect(contour)annotation = {"segmentation": [],"area": ground_truth_area,"iscrowd": 0,"image_id": ann_count,"bbox": [x,y,w,h],"category_id": category_id,"id": segmentation_id}# 求segmentation部分contour = np.flip(contour, axis=0)segmentation = contour.ravel().tolist()annotation["segmentation"].append(segmentation)annotations.append(annotation)segmentation_id = segmentation_id + 1return annotations# mask图像路径
block_mask_path = '...'
block_mask_image_files = sorted(os.listdir(block_mask_path))# coco json保存的位置
jsonPath = "..."
annCount = 1
imageCount = 1
# 原图像的路径, 原图像和mask图像的名称是一致的。
path = "..."
rgb_image_files = sorted(os.listdir(path))
if block_mask_image_files!=rgb_image_files: print("error")with io.open(jsonPath, 'w', encoding='utf8') as output:# 那就全部写在一个文件夹好了output.write(unicode('{\n'))# 基本信息output.write(unicode('"info": [\n'))output.write(unicode('{\n'))info={"year": "2023","version": "1","contributor": "bulibuli","url": "","date_created": "2023-01-17"}str_ = json.dumps(info, indent=4)str_ = str_[1:-1]if len(str_) > 0:output.write(unicode(str_))output.write(unicode('}\n'))output.write(unicode('],\n'))#lisenceoutput.write(unicode('"lisence": [\n'))output.write(unicode('{\n'))info={"id": 1,"url": "https://creativecommons.org/licenses/by/4.0/","name": "CC BY 4.0"}str_ = json.dumps(info, indent=4)str_ = str_[1:-1]if len(str_) > 0:output.write(unicode(str_))output.write(unicode('}\n'))output.write(unicode('],\n'))# categoryoutput.write(unicode('"categories": [\n'))output.write(unicode('{\n'))categories = {"supercategory": "polyp","id": 1,"name": "polyp"}str_ = json.dumps(categories, indent=4)str_ = str_[1:-1]if len(str_) > 0:output.write(unicode(str_))output.write(unicode('}\n'))output.write(unicode('],\n'))# imagesoutput.write(unicode('"images": [\n'))for image in rgb_image_files:if os.path.exists(os.path.join(block_mask_path, image)):output.write(unicode('{'))block_im = cv2.imread(os.path.join(path, image))h,w,_=block_im.shapeannotation = {"height": h,"width": w,"id": imageCount,"file_name": image}str_ = json.dumps(annotation, indent=4)str_ = str_[1:-1]if len(str_) > 0:output.write(unicode(str_))imageCount = imageCount + 1if (image == rgb_image_files[-1]):output.write(unicode('}\n'))else:output.write(unicode('},\n'))output.write(unicode('],\n'))# 写annotationsoutput.write(unicode('"annotations": [\n'))for i in range(len(block_mask_image_files)):if os.path.exists(os.path.join(path, block_mask_image_files[i])):block_image = block_mask_image_files[i]# print(block_image)# 读取二值图像block_im = cv2.imread(os.path.join(block_mask_path, block_image), 0)_, block_im = cv2.threshold(block_im, 100, 1, cv2.THRESH_BINARY)if not block_im is None:block_im = np.array(block_im, dtype=object).astype(np.uint8)block_anno = maskToanno(block_im, annCount, 1)# print(block_image,len(block_anno))for b in block_anno:str_block = json.dumps(b, indent=4)str_block = str_block[1:-1]if len(str_block) > 0:output.write(unicode('{\n'))output.write(unicode(str_block))if (block_image == rgb_image_files[-1] and b == block_anno[-1]):output.write(unicode('}\n'))else:output.write(unicode('},\n'))annCount = annCount + 1else:print(block_image)output.write(unicode(']\n'))output.write(unicode('}\n'))