File size: 5,510 Bytes
4875d48
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
from dataclasses import dataclass
from typing import Optional, Tuple, Union, List
from PIL import Image
import PIL
import torch
import torch.nn as nn
import torch.nn.functional as F
from transformers import (
    PreTrainedModel,
    CLIPSegProcessor,
    CLIPSegForImageSegmentation,
)
from transformers.modeling_outputs import ModelOutput

from .config import ClipSegMultiClassConfig
from sklearn.metrics import precision_score, recall_score, f1_score, accuracy_score
import numpy as np
from torch.utils.data import DataLoader
from collections import defaultdict

def flatten_outputs(preds, targets, num_classes):
    """Flatten predictions and targets to 1D arrays, filter ignored labels."""
    preds = preds.cpu().numpy().reshape(-1)
    targets = targets.cpu().numpy().reshape(-1)

    mask = (targets >= 0) & (targets < num_classes)
    return preds[mask], targets[mask]

def compute_metrics(all_preds, all_targets, num_classes, average="macro"):
    y_pred = np.concatenate(all_preds)
    y_true = np.concatenate(all_targets)

    metrics = {
        "accuracy": accuracy_score(y_true, y_pred),
        "precision": precision_score(y_true, y_pred, average=average, zero_division=0),
        "recall": recall_score(y_true, y_pred, average=average, zero_division=0),
        "f1": f1_score(y_true, y_pred, average=average, zero_division=0),
    }

    return metrics


@dataclass
class ClipSegMultiClassOutput(ModelOutput):
    loss: Optional[torch.FloatTensor] = None
    logits: Optional[torch.FloatTensor] = None
    predictions: Optional[torch.LongTensor] = None


class ClipSegMultiClassModel(PreTrainedModel):
    config_class = ClipSegMultiClassConfig
    base_model_prefix = "clipseg_multiclass"

    def __init__(self, config: ClipSegMultiClassConfig):
        super().__init__(config)

        self.config = config
        self.class_labels = config.class_labels
        self.num_classes = config.num_classes
        self.processor = CLIPSegProcessor.from_pretrained(config.model)
        self.clipseg = CLIPSegForImageSegmentation.from_pretrained(config.model)
        self.loss_fct = nn.CrossEntropyLoss()

    def forward(

        self,

        pixel_values: Optional[torch.Tensor] = None,

        input_ids: Optional[torch.Tensor] = None,

        labels: Optional[torch.Tensor] = None,

        **kwargs

    ) -> ClipSegMultiClassOutput:

        if pixel_values is None or input_ids is None:
            raise ValueError("Both `pixel_values` and `input_ids` must be provided.")

        pixel_values = pixel_values.to(self.device)
        input_ids = input_ids.to(self.device)

        outputs = self.clipseg(pixel_values=pixel_values, input_ids=input_ids)
        raw_logits = outputs.logits  # shape: [B * C, H, W]

        B = raw_logits.shape[0] // self.num_classes
        C = self.num_classes
        H, W = raw_logits.shape[-2:]

        logits = raw_logits.view(B, C, H, W)  # [B, C, H, W]
        pred = torch.argmax(logits, dim=1)   # [B, H, W]

        loss = self.loss_fct(logits, labels.long()) if labels is not None else None

        return ClipSegMultiClassOutput(
            loss=loss,
            logits=logits,
            predictions=pred
        )

    @torch.no_grad()
    def predict(self, images: Union[List, "PIL.Image.Image"]) -> torch.Tensor:
        self.eval()
        if isinstance(images, Image.Image):
            images = [images]

        inputs = self.processor(
            images=[img for img in images for _ in self.class_labels],
            text=self.class_labels * len(images),
            return_tensors="pt",
            padding=True,
            truncation=True
        ).to(self.device)

        output = self.forward(
            pixel_values=inputs["pixel_values"],
            input_ids=inputs["input_ids"]
        )
        return output.predictions

    def evaluate(self, dataloader: torch.utils.data.DataLoader) -> dict:
        from sklearn.metrics import accuracy_score, precision_score, recall_score, f1_score
        import numpy as np

        self.eval()

        all_preds = []
        all_targets = []

        with torch.no_grad():
            for batch in dataloader:
                pixel_values = batch["pixel_values"].to(self.device)     # [B * C, 3, H, W]
                input_ids = batch["input_ids"].to(self.device)           # [B * C, T]
                labels = batch["labels"].to(self.device)                 # [B, H, W]

                outputs = self.forward(pixel_values=pixel_values, input_ids=input_ids)
                preds = outputs.predictions  # [B, H, W]

                for pred, label in zip(preds, labels):
                    pred = pred.cpu().flatten()
                    label = label.cpu().flatten()

                    mask = label != 0
                    pred = pred[mask]
                    label = label[mask]

                    all_preds.append(pred)
                    all_targets.append(label)

        y_pred = torch.cat(all_preds).numpy()
        y_true = torch.cat(all_targets).numpy()

        return {
            "accuracy": accuracy_score(y_true, y_pred),
            "precision": precision_score(y_true, y_pred, average="macro", zero_division=0),
            "recall": recall_score(y_true, y_pred, average="macro", zero_division=0),
            "f1": f1_score(y_true, y_pred, average="macro", zero_division=0),
        }