RuntimeError: Given groups=1, weight of size [64, 3, 5, 5], expected input[64, 1, 128, 128] to have 3 channels, but got 1 channels instead

class Network(nn.Module):
def init(self,kernels1=1,extra_kernels=0):
self.conv1 = nn.Conv2d(in_channels = 3, out_channels = 64, kernel_size = 5, padding = (1,1))#,kernels=kernels1, stride=1)
self.bn1 = nn.BatchNorm2d(64,eps=1e-05,momentum=0.15)
self.cnn1_drop = nn.Dropout2d(p=0.15)
self.conv2 = nn.Conv2d (in_channels = 64, out_channels = 128, kernel_size = 4, padding = (1,1))
self.cnn2_drop = nn.Dropout2d(p=0.15)
self.bn2 = nn.BatchNorm2d(128,eps=1e-05,momentum=0.25)
self.conv3 = nn.Conv2d(in_channels = 128, out_channels = 256, kernel_size = 3, padding = (1,1))
self.bn3 = nn.BatchNorm2d(256,eps=1e-05,momentum=0.25)
self.cnn3_drop = nn.Dropout2d(p=0.25)
self.fc1 = nn.Linear(in_features =57600,out_features= 1000)
self.bn4 = nn.BatchNorm1d(1000)
self.cnn4_drop = nn.Dropout2d(p=0.25)
self.fc2 = nn.Linear(in_features = 1000, out_features = 100)
self.bn5 = nn.BatchNorm1d(100)
self.cnn5_drop = nn.Dropout2d(p=0.25)
self.out = nn.Linear(in_features = 100, out_features = 1)
#self.cnn6_drop = nn.Dropout2d(p=0.25)

def forward(self, t):
    t = t.view(-1, t.size(-3), t.size(-2), t.size(-1))
    #print('t', str(t.size()))
    t = self.relu(self.bn1(self.conv1(t)))
    #t=lip2d(t,kernel=3, stride=2, padding=1)
    t = F.max_pool2d(t, kernel_size = 2, stride = 2)
    t = self.cnn1_drop(t)
    #t = self.conv1(t)
   # t = F.max_pool2d(t,(t.size(-2), t.size(-1)))
   # t1 = -F.max_pool2d(-t,(t.size(-2), t.size(-1)))
    #t  =, t1),1)
    #t = t.squeeze(3).squeeze(2)
    #t = t.view (t.size(0),-1)
    #t  = t.unsqueeze(3).unsqueeze(2)
    t = self.relu(self.bn2(self.conv2(t)))
    t = F.max_pool2d(t, kernel_size = 2, stride = 2)
    t =self.cnn2_drop(t)
    t = self.relu(self.bn3(self.conv3(t)))
    t = F.max_pool2d(t, kernel_size = 2, stride = 2)
    t =self.cnn3_drop(t)
    t = t.view (t.size(0),-1)
    t = self.relu(self.bn4(self.fc1(t)))
    t =self.cnn4_drop(t)
    t = self.relu(self.bn5(self.fc2(t)))
    t =self.cnn5_drop(t)
    t = self.out(t)
    #t =self.cnn6_drop(t)
    return t

I am trying dis code , when i run it got the following error
RuntimeError: Given groups=1, weight of size [64, 3, 5, 5], expected input[64, 1, 128, 128] to have 3 channels, but got 1 channels instead

Based on the error message it seems you are passing an input with a single channel while 3 are expected. You could change the in_channels argument of the first conv layer to 1 or make sure the input has 3 channels.

def default_loader(path):
return‘RGB’) this is how i m passing input, from this function it means i m passing RGB images only right .how to make sure whether i m passing RGB images only

is it correct what i did?
def default_loader(path):
** return‘RGB’)**

Yes, this looks correct.
Check the shape of t inside the forward and see if it still reports a single channel.
Also, I don’t understand why you are using a view operation here, which should not change anything assuming the input is already a 4D tensor:

t = t.view(-1, t.size(-3), t.size(-2), t.size(-1))

ok will check .i can remove this t = t.view(-1, t.size(-3), t.size(-2), t.size(-1)) and dirctly feed input to conv1 layer

t torch.Size([64, 1, 128, 128]) this is taking single channel as input .how to pass 3channels

Try to narrow down why the input has a single channel as you expect it to have 3 based on your current description. I.e. check the output of the DataLoader, then the output of the Dataset, then the __getitem__ and narrow down why the convert("RGB") call is used.

i didnt get u properly, can u be more clear as i m beginner to this pytorch an when i give the input directly to conv1 layer without view operation i got this error
ValueError: too many values to unpack (expected 4)

Sir ,please tell me how to pass on 3channels

As @ptrblck has mentioned, you should narrow down your debugging to the outputs of your custom Dataset class and Dataloader first, as the problem essentially lies with the dimensionality of your input tensors and those are the two classes that (should) primarily deal with putting the data in a format compatible with the model.

Otherwise, you could post the code of those two classes here for us to look at and potentially help you.
Please also ensure to enclose your code within a block that begins and ends with ```

‘’'class IQADataset(Dataset):
def init(self, conf, exp_id=0, status=‘train’, loader=default_loader):
self.loader = loader
im_dir = conf[‘im_dir’]
self.patch_size = conf[‘patch_size’]
self.stride = conf[‘stride’]
datainfo = conf[‘datainfo’]

    Info = h5py.File(datainfo, 'r')
    index = Info['index'][:, int(exp_id) % 1000]
    ref_ids = Info['ref_ids'][0, :]
    test_ratio = conf['test_ratio']
    train_ratio = conf['train_ratio']
    trainindex = index[:int(train_ratio * len(index))]
    testindex = index[int((1-test_ratio) * len(index)):]
    train_index, val_index, test_index = [],[],[]
    for i in range(len(ref_ids)):
        train_index.append(i) if (ref_ids[i] in trainindex) else \
            test_index.append(i) if (ref_ids[i] in testindex) else \
    if status == 'train':
        self.index = train_index
        print("# Train Images: {}".format(len(self.index)))
        print('Ref Index:')
    if status == 'test':
        self.index = test_index
        print("# Test Images: {}".format(len(self.index)))
        print('Ref Index:')
    if status == 'val':
        self.index = val_index
        print("# Val Images: {}".format(len(self.index)))

    self.mos = Info['subjective_scores'][0, self.index]
    self.mos_std = Info['subjective_scoresSTD'][0, self.index]
    im_names = [Info[Info['im_names'][0, :][i]][()].tobytes()\
                    [::2].decode() for i in self.index]
    self.patches = ()
    self.label = []
    self.label_std = []
    for idx in range(len(self.index)):
        # print("Preprocessing Image: {}".format(im_names[idx]))
        im = self.loader(os.path.join(im_dir, im_names[idx]))

        patches = NonOverlappingCropPatches(im, self.patch_size, self.stride)
        if status == 'train':
            self.patches = self.patches + patches #
            for i in range(len(patches)):
            self.patches = self.patches + (torch.stack(patches), ) #

def __len__(self):
    return len(self.patches)

def __getitem__(self, idx):
    return self.patches[idx], (torch.Tensor([self.label[idx]]), torch.Tensor([self.label_std[idx]]))

n this is the dataloader

def get_data_loaders(config, train_batch_size, exp_id=0):
train_dataset = IQADataset(config, exp_id, ‘train’)
train_loader =,

val_dataset = IQADataset(config, exp_id, 'val')
val_loader =

if config['test_ratio']:
    test_dataset = IQADataset(config, exp_id, 'test')
    test_loader =

    return train_loader, val_loader, test_loader

return train_loader, val_loader'''

can you help me out , this is the class for Dataset n dataloader

@srishti-git1110 n @ptrblck please help me

Both of us have explained where the error is coming from and how to narrow it down.
You’ve followed up with a code snippet which is not executable and didn’t respond to any suggestions how to narrow it down, so I’m unsure how else we can help.

Oh i m sorry i was busy n came back to work yesterday only so couldn’t respond .This is the data loader in the code , i just have changed it to RGB
def default_loader(path):
** return‘L’)**
and i changed it to RGB
def default_loader(path):
** return‘RGB’)**

For your DataLoader assuming your __getitem__() call returns List[Tensor, Tensor] try this out:
next(iter(DataLoader))[0].shape it should give you [b, c, h, w]

b → batch_size
c → number of channels
h → height
w → width

and then if you are getting c = 1 you can further debug your __getitem__() as to see why
Hope this helped.

@parthshah231 thank u , i will try it.