I tried to follow your advices,
I changed the Discriminator without any problem

class Discriminator(nn.Module):
def init(self, ngpu):
super(Discriminator, self).init()
self.ngpu = ngpu
self.main = nn.Sequential(
# input is (nc) x 64 x 64
nn.Conv2d(nc, ndf, 4, 2, 1, bias=False),
nn.LeakyReLU(0.2, inplace=True),
# state size. (ndf) x 32 x 32
nn.Conv2d(ndf, ndf * 2, 4, 2, 1, bias=False),
nn.BatchNorm2d(ndf * 2),
nn.LeakyReLU(0.2, inplace=True),
# state size. (ndf2) x 16 x 16
nn.Conv2d(ndf * 2, ndf * 4, 4, 2, 1, bias=False),
nn.BatchNorm2d(ndf * 4),
nn.LeakyReLU(0.2, inplace=True),
# state size. (ndf4) x 8 x 8
nn.Conv2d(ndf * 4, ndf * 16, 4, 2, 1, bias=False),
nn.BatchNorm2d(ndf * 16),
nn.LeakyReLU(0.2, inplace=True),
# state size. (ndf*16) x 4 x 4
nn.Conv2d(ndf * 16, 1, 4, 1, 0, bias=False),
nn.Sigmoid()
)
and I tried to change the Generator like that :
class Generator(nn.Module):
def init(self, ngpu):
super(Generator, self).init()
self.ngpu = ngpu
self.main = nn.Sequential(
# input is Z, going into a convolution
nn.ConvTranspose2d( nz, ngf * 8, 4, 1, 0, bias=False),
nn.BatchNorm2d(ngf * 8),
nn.ReLU(True),
# state size. (ngf8) x 4 x 4
nn.ConvTranspose2d(ngf * 8, ngf * 4, 4, 2, 1, bias=False),
nn.BatchNorm2d(ngf * 4),
nn.ReLU(True),
# state size. (ngf4) x 8 x 8
nn.ConvTranspose2d( ngf * 4, ngf * 2, 4, 2, 1, bias=False),
nn.BatchNorm2d(ngf * 2),
nn.ReLU(True),
# state size. (ngf*2) x 16 x 16
nn.ConvTranspose2d( ngf * 4, ngf * 16, 4, 2, 1, bias=False),
nn.BatchNorm2d(ngf * 16),
nn.ReLU(True),
# state size. (ngf) x 32 x 32
nn.ConvTranspose2d( ngf * 16, 1, 4, 1, 0, bias=False),
nn.Tanh()
# state size. (nc) x 64 x 64
)
But when I run the training code I have this error :

Capture d’écran 2019-08-07 à 09.06.09.png2618×766 228 KB

Also, should I change the image_size from 64 to 1024 ?
I’d love to have some help