Raise ValueError('Expected more than 1 value per channel when training, got input size {}'.format(size)) ValueError: Expected more than 1 value per channel when training, got input size torch.Size([1, 256, 1, 1])

1

Why I got this error? my image and label are the same size(166*190 24bit rgb)
RuntimeError: stack expects each tensor to be equal size, but got [3, 185, 204] at entry 0 and [3, 190, 166] at entry 1

The following is the resize:where is wrong?
class Resize(object):

"""Resize image and/or masks."""

def __init__(self, imageresize, maskresize):

    self.imageresize = imageresize

    self.maskresize = maskresize

def __call__(self, sample):

    image, mask = sample['image'], sample['mask']

    if len(image.shape) == 3:

        image = image.transpose(1, 2, 0)

    if len(mask.shape) == 3:

        mask = mask.transpose(1, 2, 0)

    mask = cv2.resize(mask, self.maskresize, cv2.INTER_AREA)

    image = cv2.resize(image, self.imageresize, cv2.INTER_AREA)

    if len(image.shape) == 3:

        image = image.transpose(2, 0, 1)

    if len(mask.shape) == 3:

        mask = mask.transpose(2, 0, 1)

    return {'image': image,

            'mask': mask}

class ToTensor(object):

"""Convert ndarrays in sample to Tensors."""

def __call__(self, sample, maskresize=None, imageresize=None):

    image, mask = sample['image'], sample['mask']

    if len(mask.shape) == 2:

        mask = mask.reshape((1,)+mask.shape)

    if len(image.shape) == 2:

        image = image.reshape((1,)+image.shape)

    return {'image': torch.from_numpy(image),

            'mask': torch.from_numpy(mask)}

class Normalize(object):

'''Normalize image'''

def __call__(self, sample):

    image, mask = sample['image'], sample['mask']

    return {'image': image.type(torch.FloatTensor)/255,

            'mask': mask.type(torch.FloatTensor)/255}
2

This is probably due to BatchNorm. You cannot use BatchNorm with batch_size=1. You should use InstanceNorm instead.

3

Thanks, I made the change, but get this error:
RuntimeError: stack expects each tensor to be equal size, but got [3, 530, 500] at entry 0 and [3, 500, 530] at entry 3
image(32bit) and label (4bit) , the same size(500*530), is there anything wrong with my transpose process?

class Resize(object):
“”“Resize image and/or masks.”""

def __init__(self, imageresize, maskresize):
    self.imageresize = imageresize
    self.maskresize = maskresize

def __call__(self, sample):
    image, mask = sample['image'], sample['mask']
    if len(image.shape) == 3:
        image = image.transpose(1, 2, 0)
    if len(mask.shape) == 3:
        mask = mask.transpose(1, 2, 0)
    mask = cv2.resize(mask, self.maskresize, cv2.INTER_AREA)
    image = cv2.resize(image, self.imageresize, cv2.INTER_AREA)
    if len(image.shape) == 3:
        image = image.transpose(2, 0, 1)
    if len(mask.shape) == 3:
        mask = mask.transpose(2, 0, 1)

    return {'image': image,
            'mask': mask}
4

You probably have some image where the length condition is failing. This is a general error and you have to debug where the image is not getting transposed.

5

I am confusing…can you list some debug code for me?

6

Just use print statements in the resize and check manually. The resize method looks correct, so there must be something wrong elsewhere (maybe image loading)

7

Thanks a lot, I can not use the tensor in pytorch well, I will try it more.

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