usage.md

Metadata

Full metadata comparison

Metadata can be directly compared using:

def tiff      = path('image.tiff').tiff
def reference = path('reference.tiff').tiff

assert tiff.meta == reference.meta

This will check every metadata field in every directory of the TIFF files for equality.

Compare dimensions

The height and width of TIFF files can be compared using the meta.getDimensions() function:

def tiff      = path('image.tiff').tiff
def reference = path('reference.tiff').tiff

def dim          = tiff.meta.getDimensions()
def referenceDim = reference.meta.getDimensions()

assert dim == referenceDim

Check for field counts

The number of metadata fields in each directory of a TIFF file can be checked using the meta.getFieldCounts() function:

def tiff = path('image.tiff').tiff

assert tiff.meta.getFieldCounts()[0] == 10

Note that meta.getFieldCounts() returns a list, where each element corresponds to the directory at the same position.

Check for field names

The names of metadata fields in each directory of a TIFF file can be checked using the meta.getFieldNames() function:

def tiff      = path('image.tiff').tiff
def reference = path('reference.tiff').tiff

def fields          = tiff.meta.getFieldNames()
def referenceFields = reference.meta.getFieldNames()

assert fields == referenceFields
assert fields[0].contains('Compression')

Note that meta.getFieldNames() returns a list, where each element corresponds to the directory at the same position.

Check individual metadata fields

Individual (lists of) metadata fields in each directory of a TIFF file can be compared using the meta.getFields() function:

def tiff      = path('image.tiff').tiff
def reference = path('reference.tiff').tiff

def fields          = tiff.meta.getFields(['ImageWidth', 'PlanarConfiguration', 'Compression'])
def referenceFields = reference.meta.getFields(['ImageWidth', 'PlanarConfiguration', 'Compression'])

assert fields == referenceFields

Note that meta.getFields() returns a List of Maps. Each index in the list corresponds to a directory in the TIFF file. The maps assign the field name to the corresponding value.

The function meta.getFields() also accepts a single field as a String and may be called without any parameters to compare every metadata field.

Bitmaps

Full bitmap comparison

Bitmaps can be directly compared using:

def tiff      = path('image.tiff').tiff
def reference = path('reference.tiff').tiff

assert tiff.bitmaps == reference.bitmaps

Bitmap comparison with tolerance

A comparison of bitmaps, where a certain percentage of entries must be equal, can be performed using the bitmaps.matchesWithTolerance() function:

def tiff      = path('image.tiff').tiff
def reference = path('reference.tiff').tiff

assert tiff.bitmaps.matchesWithTolerance(reference.bitmaps, 80)

In this example the TIFF files image.tiff and reference.tiff are compared and 80% of bitmap entries have to match.

Bitmap comparison with checksums

The values of bitmaps can be compared using md5 checksums using the bitmaps.md5() function:

def tiff      = path('image.tiff').tiff
def reference = path('reference.tiff').tiff

def md5Sum          = tiff.bitmaps.md5()
def referenceMd5Sum = reference.bitmaps.md5()

assert md5Sum == referenceMd5Sum

This is particularly useful with snapshots:

def tiff = path('image.tiff').tiff
def md5  = tiff.bitmaps.md5()

assert snapshot(md5).match()