Yolo实例分割坐标和coco实例分割坐标间转换 python

在Yolo格式中，每个目标都用一个包含其类别、中心点、宽度和高度的矩形来表示。在COCO格式中，每个目标都用一个包含其所有像素的掩码来表示。因此，将Yolo格式转换为COCO格式需要通过计算目标的像素掩码来实现。

以下是将Yolo格式转换为COCO格式的Python代码示例：

import numpy as np
import cv2

# Yolo格式坐标转换为COCO格式坐标
def yolo2coco(bbox, img_width, img_height):
    x, y, w, h = bbox
    left = int((x - w / 2) * img_width)
    right = int((x + w / 2) * img_width)
    top = int((y - h / 2) * img_height)
    bottom = int((y + h / 2) * img_height)
    return [left, top, right, bottom]

# COCO格式坐标转换为Yolo格式坐标
def coco2yolo(bbox, img_width, img_height):
    left, top, right, bottom = bbox
    x = (left + right) / 2 / img_width
    y = (top + bottom) / 2 / img_height
    w = (right - left) / img_width
    h = (bottom - top) / img_height
    return [x, y, w, h]

# 读取Yolo格式标注文件
def read_yolo_annotation(annotation_file):
    with open(annotation_file, 'r') as f:
        lines = f.readlines()
    annotations = []
    for line in lines:
        line = line.strip()
        if not line:
            continue
        parts = line.split()
        class_id = int(parts[0])
        bbox = [float(x) for x in parts[1:]]
        annotations.append((class_id, bbox))
    return annotations

# 将Yolo格式标注转换为COCO格式标注
def yolo2coco_annotation(yolo_annotation, img_width, img_height):
    coco_annotation = []
    for class_id, bbox in yolo_annotation:
        coco_bbox = yolo2coco(bbox, img_width, img_height)
        mask = np.zeros((img_height, img_width), dtype=np.uint8)
        cv2.rectangle(mask, (coco_bbox[0], coco_bbox[1]), (coco_bbox[2], coco_bbox[3]), 1, thickness=-1)
        coco_annotation.append({'category_id': class_id, 'bbox': coco_bbox, 'segmentation': mask})
    return coco_annotation

# 将COCO格式标注转换为Yolo格式标注
def coco2yolo_annotation(coco_annotation, img_width, img_height):
    yolo_annotation = []
    for ann in coco_annotation:
        class_id = ann['category_id']
        coco_bbox = ann['bbox']
        yolo_bbox = coco2yolo(coco_bbox, img_width, img_height)
        yolo_annotation.append((class_id, yolo_bbox))
    return yolo_annotation

其中，`yolo2coco`函数将Yolo格式的坐标转换为COCO格式的坐标，`coco2yolo`函数将COCO格式的坐标转换为Yolo格式的坐标。`read_yolo_annotation`函数从Yolo格式的标注文件中读取标注信息，`yolo2coco_annotation`函数将Yolo格式的标注转换为COCO格式的标注，`coco2yolo_annotation`函数将COCO格式的标注转换为Yolo格式的标注。