图像格式转换_np.transpose(img, (2, 0, 1))

tensor–>numpy img = img.numpy()
numpy–>tensor
tensor = transforms.ToTensor()
tensor_img = tensor(img)

tensor–>PIL
CHW–>HWC img = np.transpose(img, (1,2,0))

HWC–>CHW img = np.transpose(img, (2,0,1))

查看tensor格式图像 tensor–>numpy

img,tar = test_set[0]
print(type(img))  # <class 'torch.Tensor'>
img = img.numpy()
print(type(img)) # <class 'numpy.ndarray'>
print(img.shape) # (3, 32, 32)
img = np.transpose(img, (1,2,0))
print(img.shape) # (32, 32, 3)

# opencv中的颜色通道顺序是BGR而PIL、torch里面的图像颜色通道是RGB
img=cv2.cvtColor(mat,cv2.COLOR_BGR2RGB)
cv2.imshow('image', img)
cv2.waitKey(0)
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查看tensor格式图像 tensor–>PIL

from torchvision import transforms
unloader = transforms.ToPILImage()
image = original_tensor.cpu().clone()  # clone the tensor
image = image.squeeze(0)  # remove the fake batch dimension
image = unloader(image)
image.save('example.jpg')

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