DicomTreeCompare.py

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#
# Copyright 2021, MeVis Medical Solutions AG
#
# The user may use this file in accordance with the license agreement provided with
# the Software or, alternatively, in accordance with the terms contained in a
# written agreement between the user and MeVis Medical Solutions AG.
#
# For further information use the contact form at https://www.mevislab.de/contact
#
 
from mevis import MLAB
 
 
# -- class DicomTreeCompare ------------------------------------------------------------------{{{-
 
class DicomTreeCompare:
 
    def __init__(self):
        self.printDifferences = True
        self.printOnlyFirstDifference = False
        self.outputFunction = MLAB.logError
        self._hadDifferences = False
 
    def hadDifferences(self):
        return self._hadDifferences
 
    def tagName(self, tag):
        name = tag.tagName()
        if not name:
            name = tag.id()
        elif name == "PrivateCreator":
            name += " '" + tag.toString() + "' " + tag.id()
        else:
            name += " " + tag.id()
        return name
 
    def dicomPathToString(self, path):
        result = ""
        for tag, index in path:
            result += f"in {self.tagName(tag)}, position {index} "
        return result
 
    def tagValueToString(self, tag):
        if tag.isBinary():
            return f"<{tag.numberOfValues()} items>"
        else:
            return f"'{tag.toString()}'"
 
    def dicomTagError(self, path, message, tag=None):
        if self.printDifferences:
            if not self._hadDifferences or not self.printOnlyFirstDifference:
                tagString = (", tag " + self.tagName(tag)) if tag else ""
                msg = self.dicomPathToString(path) + message + tagString
                self.outputFunction(msg)
        self._hadDifferences = True
 
    def compareTags(self, tag1, tag2, path):
        if tag1.vr() != tag2.vr():
            self.dicomTagError(path, f"Different VRs ({tag1.vr()} and {tag2.vr()})", tag1)
            return False
        elif tag1.isSequence():
            n1 = tag1.numberOfSequenceItems()
            n2 = tag2.numberOfSequenceItems()
            if n1 != n2:
                self.dicomTagError(path, f"Tags have different number of sequence items ({n1} and {n2})", tag1)
                return False
            else:
                ok = True
                for i in range(tag1.numberOfSequenceItems()):
                    ok = self.compareTrees(tag1.getSequenceItem(i), tag2.getSequenceItem(i), path + ((tag1, i),)) and ok
                return ok
        elif not tag1.isEqual(tag2):
            s1 = self.tagValueToString(tag1)
            s2 = self.tagValueToString(tag2)
            self.dicomTagError(path, f"Different values ({s1} != {s2})", tag1)
            return False
        else:
            return True
 
    def compareTrees(self, tree1, tree2, path=()):
        ok = True
        if tree1 and not tree2:
            self.dicomTagError(path, "Second tree not existing")
            return False
        elif tree2 and not tree1:
            self.dicomTagError(path, "First tree not existing")
            return False
        tags1 = list(tree1.getTags())
        tags2 = list(tree2.getTags())
        tag1 = tags1.pop(0) if tags1 else None
        tag2 = tags2.pop(0) if tags2 else None
        while tag1 or tag2:
            if (
                not tag2
                or tag1.groupId() < tag2.groupId()
                or (tag1.groupId() == tag2.groupId() and tag1.elementId() < tag2.elementId())
            ):
                self.dicomTagError(path, "Extra tag in first tree", tag1)
                ok = False
                tag1 = tags1.pop(0) if tags1 else None
            elif (
                not tag1
                or tag1.groupId() > tag2.groupId()
                or (tag1.groupId() == tag2.groupId() and tag1.elementId() > tag2.elementId())
            ):
                self.dicomTagError(path, "Extra tag in second tree", tag2)
                ok = False
                tag2 = tags2.pop(0) if tags2 else None
            else:
                ok = self.compareTags(tag1, tag2, path) and ok
                tag1 = tags1.pop(0) if tags1 else None
                tag2 = tags2.pop(0) if tags2 else None
        return ok
 
 
# --------------------------------------------------------------------------------------------}}}-
 
 
# -- def compareDicomTrees -------------------------------------------------------------------{{{-
 
def compareDicomTrees(
    tree1, tree2, printDifferences=True, printOnlyFirstDifference=False, outputFunction=MLAB.logError
):
    dc = DicomTreeCompare()
    dc.printDifferences = printDifferences
    dc.printOnlyFirstDifference = printOnlyFirstDifference
    dc.outputFunction = outputFunction
    return dc.compareTrees(tree1, tree2)
 
 
# --------------------------------------------------------------------------------------------}}}-