File size: 5,208 Bytes
cbef243
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
from typing import Tuple, Union

import gradio as gr
import matplotlib.pyplot as plt
import torch
from PIL import Image

import bcos.models.pretrained as pretrained
from bcos.data.categories import IMAGENET_CATEGORIES

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")


def get_model(model_name):
    model = getattr(pretrained, model_name)(pretrained=True)
    model = model.to(device)
    model.eval()
    return model


MODEL_NAMES = pretrained.list_available()


class NormalizationMode:
    # this is normalization for the explanations!
    INDIVIDUAL = "individual"
    WRT_PREDICTION = "wrt prediction's confidence"
    INDIVIDUAL_X_CONFIDENCE = "individual×confidence"

    @classmethod
    def all(cls):
        return [cls.WRT_PREDICTION, cls.INDIVIDUAL_X_CONFIDENCE, cls.INDIVIDUAL]


def freeze(model):
    for param in model.parameters():
        param.requires_grad = False


def run(
    model_name: str,
    input_image: Image,
    do_resize: bool,
    do_center_crop: bool,
    normalization_mode: str,
    smooth: int,
    alpha_percentile: Union[int, float],
    plot_dpi: int,
    topk: int = 5,
) -> Tuple[dict, plt.Figure]:
    # cleanup previous stuff
    plt.close("all")
    torch.cuda.empty_cache()

    # preprocess - get model and transform input image
    model = get_model(model_name)
    freeze(model)
    x = model.transform.transform_with_options(
        input_image,
        center_crop=do_center_crop,
        resize=do_resize,
    )
    x = x.unsqueeze(0).to(device).requires_grad_()

    # predict and explain
    with model.explanation_mode():
        out = model(x)

        topk_values, topk_preds = torch.topk(out, topk, dim=1)
        topk_values, topk_preds = topk_values[0], topk_preds[0]

        dynamic_weights = []  # list of grad tensors of shape (C, H, W)
        for i in range(topk):
            topk_values[i].backward(inputs=[x], retain_graph=i < topk - 1)
            dynamic_weights.append(
                x.grad.detach().cpu()[0],
            )
            x.grad = None  # reset

    # prepare output labels+confidences
    topk_probabilities = (
        model.to_probabilities(out.detach()).topk(topk, dim=1).values[0].cpu()
    )
    confidences = {
        IMAGENET_CATEGORIES[i]: v.item() for i, v in zip(topk_preds, topk_probabilities)
    }

    # output plot of images
    output_fig, axs = plt.subplots(
        1, topk + 1, dpi=plot_dpi, figsize=((topk + 1) * 2.1, 2)
    )

    # visualize input image
    x = x.detach().cpu()[0]
    axs[0].imshow(x[:3].permute(1, 2, 0).numpy())
    axs[0].set_xlabel("Input Image")

    # visualize explanations
    pred_confidence = topk_probabilities[0]  # first one is pred
    for i, ax in enumerate(axs[1:]):
        expl = model.gradient_to_image(
            x,
            dynamic_weights[i],
            smooth=smooth,
            alpha_percentile=alpha_percentile,
        )

        if normalization_mode == NormalizationMode.INDIVIDUAL_X_CONFIDENCE:
            expl[:, :, -1] *= topk_probabilities[i].item()
        elif normalization_mode == NormalizationMode.WRT_PREDICTION and i > 0:
            expl[:, :, -1] *= (topk_probabilities[i] / pred_confidence).item()
        else:  # NormalizationMode.INDIVIDUAL
            pass

        ax.imshow(expl)
        ax.set_xlabel(IMAGENET_CATEGORIES[topk_preds[i]])

    for ax in axs:
        ax.set_xticks([])
        ax.set_yticks([])

    output_fig.tight_layout()

    return confidences, output_fig


with gr.Blocks() as demo:
    # basic info
    gr.Markdown(
        """# B-cos Explanation Generation Demo
        [Repository](https://github.com/B-cos/B-cos-v2/)
        """
    )

    with gr.Row():
        selected_model = gr.Dropdown(
            MODEL_NAMES, value="densenet121_long", label="Select model"
        )

        with gr.Accordion("Options", open=False):
            do_resize = gr.Checkbox(
                label="Resize input image's shorter side to 256", value=True
            )
            do_center_crop = gr.Checkbox(
                label="Center crop input image to 224x224", value=False
            )
            normalization_mode = gr.Radio(
                NormalizationMode.all(),
                value=NormalizationMode.WRT_PREDICTION,
                label="Normalization Mode",
            )

            smooth = gr.Slider(1, 51, value=15, step=2, label="Smoothing kernel size")
            alpha_percentile = gr.Number(value=99.99, label="Percentile")
            plot_dpi = gr.Number(value=100, label="Plot DPI")

    input_image = gr.Image(type="pil", label="Image")
    run_button = gr.Button("Predict and Explain", variant="primary")

    # will contain all outputs in a plot
    output = gr.Plot(label="Explanations")
    # labels
    output_labels = gr.Label(label="Top-5 Predictions")

    run_button.click(
        fn=run,
        inputs=[
            selected_model,
            input_image,
            do_resize,
            do_center_crop,
            normalization_mode,
            smooth,
            alpha_percentile,
            plot_dpi,
        ],
        outputs=[output_labels, output],
        scroll_to_output=True,
    )


demo.launch(
    queue=True,
)