def processFile(filename, inDir, outDir, dichroics, mergeList):

	if mergeList is None:
		merge = False
	else:
		merge = True
	
	filenameExExt = os.path.splitext(filename)[0]
	filepath = inDir + filename
      
	# parse metadata
	reader = ImageReader()
	omeMeta = MetadataTools.createOMEXMLMetadata()
	reader.setMetadataStore(omeMeta)
	reader.setId(filepath)
	numChannels = reader.getSizeC()
	numSlices = reader.getSizeZ()
	numFrames = reader.getSizeT()
	seriesCount = reader.getSeriesCount()

	globalMetadata = reader.getGlobalMetadata()
	seriesMetadata = reader.getSeriesMetadata()

	objLensName = globalMetadata['- Objective Lens name #1']

	areaRotation = float(seriesMetadata['area rotation #1'])
	acquisitionValueRotation = float(seriesMetadata['acquisitionValue rotation #1'])
	if 'regionInfo rotation #1' in seriesMetadata:
		regionInfoRotation = float(seriesMetadata['regionInfo rotation #1'])
	else:
		regionInfoRotation = float(0)

	totalRotation = areaRotation + regionInfoRotation
	physSizeX = omeMeta.getPixelsPhysicalSizeX(0)
	physSizeY = omeMeta.getPixelsPhysicalSizeY(0)
	pxSizeX = physSizeX.value(UNITS.MICROM)
	pxSizeY = physSizeY.value(UNITS.MICROM)

	# log metadata
	IJ.log("\nMETADATA")
	#IJ.log("Filename: " + filepath)
	IJ.log("Number of series: " + str(seriesCount))
	IJ.log("Number of channels: " + str(numChannels))
	IJ.log("Number of frames: " + str(numFrames))
	IJ.log("Number of slices: " + str(numSlices))
	IJ.log("Objective lens: " + objLensName)
	IJ.log("FOV rotation: " + str(areaRotation))
	IJ.log("ROI rotation: " + str(regionInfoRotation))
	IJ.log("Total rotation: " + str(totalRotation))
	IJ.log("Pixel size:")
	IJ.log("\t\tX = " + str(physSizeX.value()) + " " + physSizeX.unit().getSymbol())
	IJ.log("\t\tY = " + str(physSizeY.value()) + " " + physSizeY.unit().getSymbol())
  
	if merge:
		tifDir = outDir + "." + str(datetime.now()).replace(" ", "").replace(":", "") + "/"
		if not os.path.exists(tifDir):
			os.makedirs(tifDir)
			IJ.log("\nCreated temporary folder: " + tifDir + "\n")
		else:
			IJ.log("Unable to create temporary folder!\n")
	else:
		tifDir = outDir + filenameExExt + "/"
		if not os.path.exists(tifDir):
			os.makedirs(tifDir)
			IJ.log("\nCreated subfolder: " + tifDir + "\n")
		else:
			IJ.log("\nSubfolder " + tifDir +  " already exists.\n")

	# correct images
	tifFilePaths = []
	for i in range(numChannels):
		ip = extractChannel(oirFile=filepath, ch=i)
		if dichroics[i] == "DM1":
			IJ.log("Channel " + str(i+1) + " was imaged using DM1, so no correction required.")
		else:
			offsets = getOffset(obj=objLensName,dm=dichroicDict[dichroics[i]])
			xom = offsets['x']
			yom = offsets['y']
			if abs(totalRotation) > 0.1:
				rotOff = rotateOffset(x=xom, y=yom, angle=-totalRotation)
				xom = rotOff['x']
				yom = rotOff['y']
			xop = int(round(xom/pxSizeX))
			yop = int(round(yom/pxSizeY))
			IJ.log("Channel " + str(i+1) + " offsets")
			IJ.log("\t\tMicrometres")
			IJ.log("\t\t\t\tx = " + str(xom))
			IJ.log("\t\t\t\ty = " + str(yom))
			IJ.log("\t\tPixels")
			IJ.log("\t\t\t\tx = " + str(xop))
			IJ.log("\t\t\t\ty = " + str(yop))
			IJ.run(ip, "Translate...", "x=" + str(-xop) + " y=" + str(-yop) + " interpolation=None stack")

		tifFilePath = tifDir + filenameExExt + "_ch_"+str(i+1)+".tif"
		tifFilePaths.append(tifFilePath)
		if os.path.exists(tifFilePath):
			IJ.log("\nOutput file exists: " + tifFilePath)
			IJ.log("Rerun plugin choosing a different output folder")
			IJ.log("or delete file and then rerun plugin.")
			IJ.log("Image processing terminated!\n")
			return
		FileSaver(ip).saveAsTiff(tifFilePath)

	if merge:
		max_list = []
		for i in range(len(mergeList)):
			if mergeList[i] != None:
				mergeList[i] = readSingleChannelImg(tifFilePaths[mergeList[i]])
				channel = mergeList[i]#https://python.hotexamples.com/examples/ij.plugin/RGBStackMerge/mergeChannels/python-rgbstackmerge-mergechannels-method-examples.html
				projector = ZProjector(channel)
				projector.setMethod(ZProjector.MAX_METHOD)
				projector.doProjection()
				max_list.append(projector.getProjection())
		merged = RGBStackMerge.mergeChannels(mergeList, False)
		merged_max = RGBStackMerge.mergeChannels(max_list, False)
		mergedChannelFilepath = outDir + filenameExExt + ".tif"
		maxMergedChannelFilepath = outDir + filenameExExt + "_max.tif"
		if os.path.exists(mergedChannelFilepath):
			IJ.log("\nOutput file exists: " + mergedChannelFilepath)
			IJ.log("Rerun plugin choosing a different output folder")
			IJ.log("or delete file and then rerun plugin.")
			IJ.log("Image processing terminated!\n")
		FileSaver(merged).saveAsTiff(mergedChannelFilepath)
		FileSaver(merged_max).saveAsTiff(maxMergedChannelFilepath)
		for tf in tifFilePaths:
			os.remove(tf)
		os.rmdir(tifDir)	

	IJ.log("\nFinished processing file:\n" + filepath + "\n")
	if merge:
		IJ.log("Image file with channels aligned:\n" + outDir + filenameExExt + ".tif\n")
	else:
		IJ.log("Aligned images (one tiff file for each channel) can be found in:\n" + tifDir + "\n")
def processFile():
	# start logging
	IJ.log("\n______________________________\n\n\t\tOlympus DM correction\n\t\tVersion " + pluginVersion +"\n______________________________\n")

	# ask user for file
	ofd = OpenDialog("Choose a file", None)  
	filename = ofd.getFileName()  
  
	if filename is None:  
  		IJ.log("User canceled the dialog!\nImage processing canceled!\n")
  		return

  	directory = ofd.getDirectory()  
  	filepath = directory + filename  
  	IJ.log("File path: " + filepath)

	if not filename.endswith(".oir"):
		IJ.log("Not an Olympus (.oir) file.\nNo image to process.\n")
		return

	filenameExExt = os.path.splitext(filename)[0]
      
	# parse metadata
	reader = ImageReader()
	omeMeta = MetadataTools.createOMEXMLMetadata()
	reader.setMetadataStore(omeMeta)
	reader.setId(filepath)
	numChannels = reader.getSizeC()
	numSlices = reader.getSizeZ()
	numFrames = reader.getSizeT()
	seriesCount = reader.getSeriesCount()

	globalMetadata = reader.getGlobalMetadata()
	seriesMetadata = reader.getSeriesMetadata()

	objLensName = globalMetadata['- Objective Lens name #1']

	areaRotation = float(seriesMetadata['area rotation #1'])
	acquisitionValueRotation = float(seriesMetadata['acquisitionValue rotation #1'])
	if 'regionInfo rotation #1' in seriesMetadata:
		regionInfoRotation = float(seriesMetadata['regionInfo rotation #1'])
	else:
		regionInfoRotation = float(0)

	totalRotation = areaRotation + regionInfoRotation
	physSizeX = omeMeta.getPixelsPhysicalSizeX(0)
	physSizeY = omeMeta.getPixelsPhysicalSizeY(0)
	pxSizeX = physSizeX.value(UNITS.MICROM)
	pxSizeY = physSizeY.value(UNITS.MICROM)

	# log metadata
	IJ.log("\nMETADATA")
	#IJ.log("Filename: " + filepath)
	IJ.log("Number of series: " + str(seriesCount))
	IJ.log("Number of channels: " + str(numChannels))
	IJ.log("Number of frames: " + str(numFrames))
	IJ.log("Number of slices: " + str(numSlices))
	IJ.log("Objective lens: " + objLensName)
	IJ.log("FOV rotation: " + str(areaRotation))
	IJ.log("ROI rotation: " + str(regionInfoRotation))
	IJ.log("Total rotation: " + str(totalRotation))
	IJ.log("Pixel size:")
	IJ.log("\t\tX = " + str(physSizeX.value()) + " " + physSizeX.unit().getSymbol())
	IJ.log("\t\tY = " + str(physSizeY.value()) + " " + physSizeY.unit().getSymbol())

	# ask user to identify dichroic mirror used for each channel  
	gdDM = GenericDialog("Dichroic mirrors")
	DMs = ["DM1", "DM2", "DM3", "DM4", "DM5"] 
	for i in range(numChannels):
		gdDM.addChoice("Channel " + str(i+1), DMs, DMs[0])
	gdDM.addCheckbox("Merge channels", False) 
	gdDM.showDialog()
	if gdDM.wasCanceled():
		IJ.log("User canceled the dialog!\nImage processing canceled!\n")
		return
	dichroics = []
	for i in range(numChannels):
		dichroics.append(gdDM.getNextChoice())
	merge = gdDM.getNextBoolean()
	IJ.log("\nUser selected dichroic mirrors")
	for i in range(numChannels):
		IJ.log("\t\tChannel " + str(i+1) + ": " + dichroics[i])	

	if merge:
		channels = []
		chDict = {}
		for i in range(numChannels):
			chName = "Channel"+str(i+1)
			channels.append(chName)
			chDict[chName] = i
		channels.append("NONE")
		colourChoices = ["red", "green", "blue", "gray", "cyan", "magenta", "yellow"]
		gdMerge = GenericDialog("Merge channels")
		for c in colourChoices:
			gdMerge.addChoice(c + ":", channels, channels[numChannels])
		gdMerge.showDialog()
		if gdMerge.wasCanceled():
			IJ.log("User canceled the dialog!\nImage processing canceled!\n")
			return
		IJ.log("\nUser selected channel colours")
		mergeList = []
		for i in range(len(colourChoices)):
			ch = gdMerge.getNextChoice()
			if ch == "NONE":
				mergeList.append(None)
			else:
				mergeList.append(chDict[ch])
				IJ.log("\t\t" + colourChoices[i] + ": " + ch)

	# ask user for an output directory
	dc = DirectoryChooser("Choose folder for output")  
	od = dc.getDirectory()    
	if od is None:  
		IJ.log("User canceled the dialog!\nImage processing canceled!\n")  
		return  
  
	if merge:
		tifDir = od + "." + str(datetime.now()).replace(" ", "").replace(":", "") + "/"
		if not os.path.exists(tifDir):
			os.makedirs(tifDir)
			IJ.log("\nCreated temporary folder: " + tifDir + "\n")
		else:
			IJ.log("Unable to create temporary folder!\n")
	else:
		tifDir = od + filenameExExt + "/"
		if not os.path.exists(tifDir):
			os.makedirs(tifDir)
			IJ.log("\nCreated subfolder: " + tifDir + "\n")
		else:
			IJ.log("\nSubfolder " + tifDir +  " already exists")

	# correct images
	tifFilePaths = []
	for i in range(numChannels):
		ip = extractChannel(oirFile=filepath, ch=i)
		if dichroics[i] == "DM1":
			IJ.log("Channel " + str(i+1) + " was imaged using DM1, so no correction required.")
		else:
			offsets = getOffset(obj=objLensName,dm=dichroicDict[dichroics[i]])
			xom = offsets['x']
			yom = offsets['y']
			if abs(totalRotation) > 0.1:
				rotOff = rotateOffset(x=xom, y=yom, angle=-totalRotation)
				xom = rotOff['x']
				yom = rotOff['y']
			xop = int(round(xom/pxSizeX))
			yop = int(round(yom/pxSizeY))
			IJ.log("Channel " + str(i+1) + " offsets")
			IJ.log("\t\tMicrometres")
			IJ.log("\t\t\t\tx = " + str(xom))
			IJ.log("\t\t\t\ty = " + str(yom))
			IJ.log("\t\tPixels")
			IJ.log("\t\t\t\tx = " + str(xop))
			IJ.log("\t\t\t\ty = " + str(yop))
			IJ.run(ip, "Translate...", "x=" + str(-xop) + " y=" + str(-yop) + " interpolation=None stack")

		tifFilePath = tifDir + filenameExExt + "_ch_"+str(i+1)+".tif"
		tifFilePaths.append(tifFilePath)
		if os.path.exists(tifFilePath):
			IJ.log("\nOutput file exists: " + tifFilePath)
			IJ.log("Rerun plugin choosing a different output folder")
			IJ.log("or delete file and then rerun plugin.")
			IJ.log("Image processing terminated!\n")
			return
		FileSaver(ip).saveAsTiff(tifFilePath)

	if merge:
		for i in range(len(mergeList)):
			if mergeList[i] != None:
				mergeList[i] = readSingleChannelImg(tifFilePaths[mergeList[i]])
		merged = RGBStackMerge.mergeChannels(mergeList, False)
		mergedChannelFilepath = od + filenameExExt + ".tif"
		if os.path.exists(mergedChannelFilepath):
			IJ.log("\nOutput file exists: " + mergedChannelFilepath)
			IJ.log("Rerun plugin choosing a different output folder")
			IJ.log("or delete file and then rerun plugin.")
			IJ.log("Image processing terminated!\n")
		FileSaver(merged).saveAsTiff(mergedChannelFilepath)
		for tf in tifFilePaths:
			os.remove(tf)
		os.rmdir(tifDir)
			
	IJ.log("\nFinished processing file:\n" + filepath + "\n")
	if merge:
		IJ.log("Image file with channels aligned:\n" + od + filenameExExt + ".tif\n")
	else:
		IJ.log("Aligned images (one tiff file for each channel) can be found in:\n" + tifDir + "\n")