YOLOV5补边操作
时间: 2024-04-16 11:20:20 浏览: 14
根据引用所述,YOLOv5对原始图像自适应的添加最少的黑边,以减少信息冗余,提高目标检测速度。具体实现方法如下:
1. 对于宽高比例小于1的图像,将其缩放到416x416或者608x608的大小,并在图像高度上添加黑边,使得黑边的高度等于宽度与高度差的一半。
2. 对于宽高比例大于1的图像,将其缩放到416x416或者608x608的大小,并在图像宽度上添加黑边,使得黑边的宽度等于宽度与高度差的一半。
3. 对于宽高比例等于1的图像,将其缩放到416x416或者608x608的大小,不需要添加黑边。
下面是一个示例代码,演示如何使用YOLOv5对图像进行补边操作:
```python
import cv2
import numpy as np
def letterbox(img, new_shape=(416, 416), color=(114, 114, 114), auto=True, scaleFill=False, scaleup=True):
shape = img.shape[:2] # current shape [height, width]
if isinstance(new_shape, int):
new_shape = (new_shape, new_shape)
# Scale ratio (new / old)
r = min(new_shape[0] / shape[0], new_shape[1] / shape[1])
if not scaleup: # only scale down, do not scale up (for better test mAP)
r = min(r, 1.0)
# Compute padding
ratio = r, r # width, height ratios
new_unpad = int(round(shape[1] * r)), int(round(shape[0] * r))
dw, dh = new_shape[1] - new_unpad[0], new_shape[0] - new_unpad[1]
if auto: # minimum rectangle
dw, dh = np.mod(dw, 64), np.mod(dh, 64) # wh padding
elif scaleFill: # stretch
dw, dh = 0.0, 0.0
new_unpad = (new_shape[1], new_shape[0])
ratio = new_shape[1] / shape[1], new_shape[0] / shape[0] # width, height ratios
dw /= 2 # divide padding into 2 sides
dh /= 2
if shape[::-1] != new_unpad: # resize
img = cv2.resize(img, new_unpad, interpolation=cv2.INTER_LINEAR)
top, bottom = int(round(dh - 0.1)), int(round(dh + 0.1))
left, right = int(round(dw - 0.1)), int(round(dw + 0.1))
img = cv2.copyMakeBorder(img, top, bottom, left, right, cv2.BORDER_CONSTANT, value=color) # add border
return img, ratio, (dw, dh)
# 读取图像
img = cv2.imread('test.jpg')
# 对图像进行补边操作
img, _, _ = letterbox(img, new_shape=(608, 608))
# 显示结果
cv2.imshow('image', img)
cv2.waitKey(0)
cv2.destroyAllWindows()
```