Python 使用 ITK ImageFileWriter 串流分批寫入大型檔案教學與範例

import itk

# 設定分割數量
numberOfSplits = 4

# 影像維度
Dimension = 3

# 輸入影像類型
InputPixelType = itk.US
InputImageType = itk.Image[InputPixelType, Dimension]

# 輸出影像類型
OutputPixelType = itk.UC
OutputImageType = itk.Image[OutputPixelType, Dimension]

# 讀取 MHA 影像檔案
inputImageFilename = "input.mha"
outputImageFilename = "output.mha"

# 建立影像 Reader
reader = itk.ImageFileReader[InputImageType].New(FileName=inputImageFilename)

# 建立 PipelineMonitorImageFilter 查看 Streaming 每次處理的範圍
monitorFilter = itk.PipelineMonitorImageFilter[InputImageType].New()
monitorFilter.SetInput(reader.GetOutput())

# 影像資料轉換
rescaler = itk.RescaleIntensityImageFilter[InputImageType, InputImageType].New()
rescaler.SetInput(monitorFilter.GetOutput())
rescaler.SetOutputMinimum(0)
outputPixelTypeMaximum = itk.NumericTraits[OutputPixelType].max()
rescaler.SetOutputMaximum(outputPixelTypeMaximum)

# 影像轉型
castImageFilter = itk.CastImageFilter[InputImageType, OutputImageType].New()
castImageFilter.SetInput(rescaler.GetOutput())

# 寫入影像檔案
writer = itk.ImageFileWriter[OutputImageType].New()
writer.SetFileName(outputImageFilename)
writer.SetInput(castImageFilter.GetOutput())
writer.SetNumberOfStreamDivisions(numberOfSplits)

# 實際執行
writer.Update()

# 輸出 Streaming 的分批 Region 資訊
updatedRequestedRegions = monitorFilter.GetUpdatedRequestedRegions()
print("Updated RequestedRegion's:")
for r in range(len(updatedRequestedRegions)):
    print('  ' + str(updatedRequestedRegions[r]))