Table Of Contents
Table Of Contents

1. Getting Started with FCN Pre-trained Models

This is a quick demo of using GluonCV FCN model on PASCAL VOC dataset. Please follow the installation guide to install MXNet and GluonCV if not yet.

import mxnet as mx
from mxnet import image
from mxnet.gluon.data.vision import transforms
import gluoncv
# using cpu
ctx = mx.cpu(0)

Prepare the image

download the example image

url = 'https://raw.githubusercontent.com/dmlc/web-data/master/gluoncv/segmentation/voc_examples/1.jpg'
filename = 'example.jpg'
gluoncv.utils.download(url, filename)

Out:

Downloading example.jpg from https://raw.githubusercontent.com/dmlc/web-data/master/gluoncv/segmentation/voc_examples/1.jpg...

load the image

img = image.imread(filename)

from matplotlib import pyplot as plt
plt.imshow(img.asnumpy())
plt.show()
../../_images/sphx_glr_demo_fcn_001.png

normalize the image using dataset mean

transform_fn = transforms.Compose([
    transforms.ToTensor(),
    transforms.Normalize([.485, .456, .406], [.229, .224, .225])
])
img = transform_fn(img)
img = img.expand_dims(0).as_in_context(ctx)

Load the pre-trained model and make prediction

get pre-trained model

model = gluoncv.model_zoo.get_model('fcn_resnet101_voc', pretrained=True)

make prediction using single scale

output = model.demo(img)
predict = mx.nd.squeeze(mx.nd.argmax(output, 1)).asnumpy()

Add color pallete for visualization

from gluoncv.utils.viz import get_color_pallete
import matplotlib.image as mpimg
mask = get_color_pallete(predict, 'pascal_voc')
mask.save('output.png')

show the predicted mask

mmask = mpimg.imread('output.png')
plt.imshow(mmask)
plt.show()
../../_images/sphx_glr_demo_fcn_002.png
More Examples
https://raw.githubusercontent.com/dmlc/web-data/master/gluoncv/segmentation/voc_examples/4.jpg https://raw.githubusercontent.com/dmlc/web-data/master/gluoncv/segmentation/voc_examples/4.png https://raw.githubusercontent.com/dmlc/web-data/master/gluoncv/segmentation/voc_examples/5.jpg https://raw.githubusercontent.com/dmlc/web-data/master/gluoncv/segmentation/voc_examples/5.png https://raw.githubusercontent.com/dmlc/web-data/master/gluoncv/segmentation/voc_examples/6.jpg https://raw.githubusercontent.com/dmlc/web-data/master/gluoncv/segmentation/voc_examples/6.png

Total running time of the script: ( 0 minutes 4.423 seconds)

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