the obtained stitched nuclei segmentation image is blank

[raycaohmu]

import fast

Download a nuclei segmentation model from the DataHub

model = fast.DataHub().download('nuclei-segmentation-model')

importer = fast.WholeSlideImageImporter
.create(fast.Config.getTestDataPath() + "/WSI/CMU-1.svs")

tissueSegmentation = fast.TissueSegmentation.create()
.connect(importer)

Generate 256x256 patches at 20X magnification with 10% overlap

generator = fast.PatchGenerator.create(
256, 256,
magnification=20,
overlapPercent=0.1
).connect(importer)
.connect(1, tissueSegmentation)

segmentation = fast.SegmentationNetwork.create(
model.paths[0] + '/high_res_nuclei_unet.onnx',
scaleFactor=1./255.
).connect(generator)

stitcher = fast.PatchStitcher.create()
.connect(segmentation)

Display the stitched segmentation results on top of the WSI

renderer = fast.ImagePyramidRenderer.create()
.connect(importer)

segmentationRenderer = fast.SegmentationRenderer.create()
.connect(stitcher)

fast.SimpleWindow2D.create()
.connect(renderer)
.connect(segmentationRenderer)
.run()

the displayed image is not the same as that in the tutorial, I get the only WSI instead of nuclei.

[smistad]

This might be the same issue as this: #223

Try this:
tissueSegmentation = fast.TissueSegmentation.create(True) .connect(importer)