B-cos / app.py
Navdeeppal Singh
mention to scroll to the end for example images
a0120f2
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 = True,
do_center_crop: bool = False,
normalization_mode: str = NormalizationMode.WRT_PREDICTION,
smooth: int = 15,
alpha_percentile: Union[int, float] = 99.99,
plot_dpi: int = 120,
topk: int = 3,
) -> 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
This demo generates explanations for images using the B-cos models.
GitHub: [link](https://github.com/B-cos/B-cos-v2/)
***Scroll to the end to try out some example images!***
"""
)
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="Explanation 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,
)
gr.Examples(
fn=run,
examples=[
[
"resnet50",
"./examples/polizeifahrzeug-zebra.png",
True,
False,
NormalizationMode.WRT_PREDICTION,
15,
99.99,
120,
],
[
"resnet50",
"./examples/cat-dog.png",
True,
False,
NormalizationMode.INDIVIDUAL,
15,
99.99,
120,
]
],
inputs=[
selected_model,
input_image,
do_resize,
do_center_crop,
normalization_mode,
smooth,
alpha_percentile,
plot_dpi,
],
outputs=[output_labels, output],
cache_examples=True,
)
demo.launch()