Heatmap is not displayed

[okamura-6880]

The visualization is done using a model created in Lobe.
I tried to get a heatmap using the usage code but what was displayed was a slightly darkened original image.

from lobe import ImageModel
from PIL import Image
import os
import sys
os.environ["CUDA_VISIBLE_DEVICES"] = "-1"
mePath = os.path.dirname(file)
model = ImageModel.load('path/to/exported/model/folder')
img = Image.open('path/to/file.jpg')
result = model.predict(img)
img.show()

print(result.prediction)

for label, confidence in result.labels:
print(f"{label}: {confidence*100}%")

heatmap = model.visualize(img)
heatmap.show()

I added a sentence to display heatmap_img at line 162 of image_model.py to test it, and found that heatmap_img was completely dark.

heatmap_img = heatmap_img.resize((height, width))
heatmap_img .show()