resnet-classifier/image_classifier/models/base.py

93 lines
2.2 KiB
Python
Executable File

import math
import torch
import torch.nn.functional as F
import traceback
from typing import Literal, overload
from functools import partial
from einops import rearrange
from torch import Tensor, einsum, nn
from torch.distributions import Categorical
from torch.nn.utils.rnn import pad_sequence
from torch.utils.checkpoint import checkpoint
from torchmetrics.classification import BinaryAccuracy, MulticlassAccuracy, MulticlassPrecision
from torchvision.models import resnet18
from ..data import get_symmap
class Model(nn.Module):
def __init__(
self,
n_tokens: int = 0, # number of token types
n_len: int = 6, # how long a sequence can be
d_model: int = 512,
):
super().__init__()
_symmap = get_symmap()
self.symmap = { f'{v}': k for k, v in _symmap.items() }
self.symmap['0'] = ""
if n_tokens == 0:
n_tokens = len(_symmap.keys())
self.n_tokens = n_tokens
self.n_len = n_len + 2 # start/stop tokens
self.d_model = d_model
self.resnet = resnet18(pretrained=False)
self.resnet.fc = nn.Linear( self.d_model, self.n_tokens * self.n_len )
self.accuracy_metric = MulticlassAccuracy(
n_tokens,
#top_k=10,
average="micro",
multidim_average="global",
)
self.precision_metric = MulticlassPrecision(
n_tokens,
#top_k=10,
average="micro",
multidim_average="global",
)
def forward(
self,
image,
text = None, #
sampling_temperature: float = 1.0,
):
x_list = torch.stack( image, dim=0 )
x = self.resnet( x_list )
y = x.view(x.size(0), self.n_len, self.n_tokens)
# either of these should do, but my VALL-E forward pass uses this, so might as well keep to it
# pred = y.argmax(dim=2)
pred = Categorical(logits=y / sampling_temperature).sample()
answer = [ "".join([ self.symmap[f'{x.item()}'] for x in t ]) for t in pred ]
if text is not None:
y_list = rearrange(pad_sequence(text), "t b -> b t")
loss = 0
for i in range(self.n_len):
if i >= y_list.shape[1]:
break
loss += F.cross_entropy( y[:, i], y_list[:, i] )
self.loss = dict(
nll=loss
)
self.stats = dict(
acc = self.accuracy_metric( pred, y_list ),
precision = self.precision_metric( pred, y_list ),
)
return answer