def __init__(self, img, staffline_height=0, staffspace_height=0):
_virtual_MusicStaves.__init__(self, img,\
staffline_height, staffspace_height)
# use external class for staff line finding
self.stafffinder = StaffFinder_projections(img,\
staffline_height=self.staffline_height,\
staffspace_height=self.staffspace_height)
# for caching staff position information
self.__staffobjlist = None
def __init__(self, img, staffline_height=0, staffspace_height=0):
_virtual_MusicStaves.__init__(self, img,\
staffline_height, staffspace_height)
# use external class for staff line finding
self.stafffinder = StaffFinder_projections(img,\
staffline_height=self.staffline_height,\
staffspace_height=self.staffspace_height)
# for caching staff position information
self.__staffobjlist = None
class MusicStaves_rl_simple(_virtual_MusicStaves):
"""This staff removal algorithm is a simplified implementation of some
ideas in Ichiro Fujinaga's dissertation (see below).
The Method:
The basic idea is that black horizontal run lengths within a staff line are
typically greater than staffspace_height, while the musical symbols
have shorter runlenghts. Thus only sufficiently short runlengths are kept.
Stafflines are detected with `StaffFinder_projections`__.
.. __: gamera.toolkits.musicstaves.stafffinder_projections.StaffFinder_projections.html
In contrast to Fujinaga's approach, we do not try a deskewing by
shearing. Moreover we only care for crossing symbols in a very crude way.
Assumptions and Limitations:
- Staff lines must not be heavily broken
- Skew correction (eg. with ``rotation_angle_projections`` from
the gamera core distribution) should be applied beforehand
- Symbols crossing staff lines are often distorted
- Staff lines highly varying in thickness are not completely removed
References:
- Ichiro Fujinaga: *Adaptive Optical Music Recognition*. Dissertation,
McGill University Montreal, Canada (1996)
- Ichiro Fujinaga: *Staff Detection and Removal*. in S. George (editor):
\"Visual Perception of Music Notation\". Idea Group (2004)
:Author: Christoph Dalitz and Thomas Karsten
"""
def __init__(self, img, staffline_height=0, staffspace_height=0):
_virtual_MusicStaves.__init__(self, img,\
staffline_height, staffspace_height)
# use external class for staff line finding
self.stafffinder = StaffFinder_projections(img,\
staffline_height=self.staffline_height,\
staffspace_height=self.staffspace_height)
# for caching staff position information
self.__staffobjlist = None
######################################################################
# remove_staves
#
# Thomas Karsten, Christoph Dalitz
#
def remove_staves(self, crossing_symbols='all', num_lines=0):
"""Detects and removes staff lines from a music/tablature image.
Signature:
``remove_staves(crossing_symbols='all', num_lines=0)``
with
*crossing_symbols*:
Determines which symbols crossing staff lines should be kept intact.
Supported values are 'all', 'bars' or 'none'.
*num_lines*:
Number of lines within one staff. A value of zero for automatic
detection is supported, but if you give the actual number, staff line
detection will improve.
"""
# save for later use
orig_image = self.image.image_copy()
# save the tall runs of the image for later
tall_runs = self.image.image_copy()
if crossing_symbols == 'all':
# try to save letters/numbers/bars crossing staves
tall_runs.filter_short_runs(self.staffline_height * 2 + 1, 'black')
elif crossing_symbols == 'bars':
# save only bar lines and flag stems
tall_runs.filter_short_runs(self.staffspace_height + 1, 'black')
elif crossing_symbols == 'none':
tall_runs.fill_white()
else:
raise RuntimeError, "Invalid value '%s' for crossing_symbols" % crossing_symbols
#tall_runs.save_tiff("tall_runs.tiff")
# keep only the stafflines
staves = self.image.image_copy()
# Solution by toom (*not* equivalent to Fujinaga):
staves.filter_narrow_runs(int(1.5 * self.staffspace_height), 'black')
# Fujinaga removes short cc's, assuming a wide distance
# between noteheads/fretsymbols:
#staves.xor_image(tall_runs, True)
#for c in staves.cc_analysis:
# if c.ncols < staffspace_height:
# c.fill_white()
#staves.save_tiff("staves.tiff")
# use external class for staff line finding
self.stafffinder.find_staves(num_lines=num_lines, preprocessing=2)
# remove the stafflines
self.image.xor_image(staves, True)
#self.image.save_tiff("staves-xor-orig.tiff")
# remove remaining speckles from staff edge
# [Possible improvement (CD):
# remove only shortruns/ccs close to staff positions]
self.image.filter_short_runs(int(self.staffline_height / 3.0 + 0.5),
'black')
#for c in self.image.cc_analysis():
# if c.nrows <= self.staffline_height * 0.5:
# c.fill_white()
#self.image.despeckle(self.staffline_height)
# copy over previously saved stuff
self.image.or_image(tall_runs, True)
# isolate remaining thin staff filaments
filaments = self.image.image_copy()
#rgb=self.image.to_rgb()
# subtract all tall runs in original image so that remaining
# thin filaments are isolated
tall_runs = orig_image.image_copy()
tall_runs.filter_short_runs(int(self.staffline_height * 2), 'black')
filaments.subtract_images(tall_runs, True)
#rgb.highlight(filaments, RGBPixel(255, 0, 0))
for c in filaments.cc_analysis():
if c.nrows <= self.staffline_height * 0.8:
pass
elif c.nrows < self.staffline_height * 1.0 and \
c.ncols > c.nrows * 2:
pass
else:
#rgb.highlight(c, RGBPixel(0, 255, 0))
c.fill_white()
#rgb.save_PNG("filaments.png")
self.image.subtract_images(filaments, True)
#self.image.despeckle(self.staffline_height*2)
del staves
del tall_runs
del filaments
del orig_image
######################################################################
# get_staffpos
#
# Christoph Dalitz
#
def get_staffpos(self, x=0):
"""Returns the y-positions of all staff lines at a given x-position.
Can only be called *after* ``remove_staves``.
Signature:
``get_staffpos(x=0)``
with
*x*:
This parameter has no effect, because the staffline is assumed to
be horizontal.
The return value is a list of `StaffObj`__.
.. __: gamera.toolkits.musicstaves.musicstaves.StaffObj.html#staffobj
"""
if not self.__staffobjlist and self.stafffinder.linelist != None:
self.__staffobjlist = []
for i, staff in enumerate(self.stafffinder.linelist):
if len(staff) > 0:
so = StaffObj()
so.staffno = i + 1
so.yposlist=[avg.average_y for avg in \
[line.to_average() for line in staff]]
so.staffrect = Rect(Point(staff[0].left_x, so.yposlist[0]),\
Point(staff[-1].right_x, so.yposlist[-1]))
self.__staffobjlist.append(so)
return self.__staffobjlist
class MusicStaves_rl_simple(_virtual_MusicStaves):
"""This staff removal algorithm is a simplified implementation of some
ideas in Ichiro Fujinaga's dissertation (see below).
The Method:
The basic idea is that black horizontal run lengths within a staff line are
typically greater than staffspace_height, while the musical symbols
have shorter runlenghts. Thus only sufficiently short runlengths are kept.
Stafflines are detected with `StaffFinder_projections`__.
.. __: gamera.toolkits.musicstaves.stafffinder_projections.StaffFinder_projections.html
In contrast to Fujinaga's approach, we do not try a deskewing by
shearing. Moreover we only care for crossing symbols in a very crude way.
Assumptions and Limitations:
- Staff lines must not be heavily broken
- Skew correction (eg. with ``rotation_angle_projections`` from
the gamera core distribution) should be applied beforehand
- Symbols crossing staff lines are often distorted
- Staff lines highly varying in thickness are not completely removed
References:
- Ichiro Fujinaga: *Adaptive Optical Music Recognition*. Dissertation,
McGill University Montreal, Canada (1996)
- Ichiro Fujinaga: *Staff Detection and Removal*. in S. George (editor):
\"Visual Perception of Music Notation\". Idea Group (2004)
:Author: Christoph Dalitz and Thomas Karsten
"""
def __init__(self, img, staffline_height=0, staffspace_height=0):
_virtual_MusicStaves.__init__(self, img,\
staffline_height, staffspace_height)
# use external class for staff line finding
self.stafffinder = StaffFinder_projections(img,\
staffline_height=self.staffline_height,\
staffspace_height=self.staffspace_height)
# for caching staff position information
self.__staffobjlist = None
######################################################################
# remove_staves
#
# Thomas Karsten, Christoph Dalitz
#
def remove_staves(self, crossing_symbols='all', num_lines=0):
"""Detects and removes staff lines from a music/tablature image.
Signature:
``remove_staves(crossing_symbols='all', num_lines=0)``
with
*crossing_symbols*:
Determines which symbols crossing staff lines should be kept intact.
Supported values are 'all', 'bars' or 'none'.
*num_lines*:
Number of lines within one staff. A value of zero for automatic
detection is supported, but if you give the actual number, staff line
detection will improve.
"""
# save for later use
orig_image=self.image.image_copy()
# save the tall runs of the image for later
tall_runs=self.image.image_copy()
if crossing_symbols == 'all':
# try to save letters/numbers/bars crossing staves
tall_runs.filter_short_runs(self.staffline_height * 2 + 1, 'black')
elif crossing_symbols == 'bars':
# save only bar lines and flag stems
tall_runs.filter_short_runs(self.staffspace_height + 1, 'black')
elif crossing_symbols == 'none':
tall_runs.fill_white()
else:
raise RuntimeError, "Invalid value '%s' for crossing_symbols" % crossing_symbols
#tall_runs.save_tiff("tall_runs.tiff")
# keep only the stafflines
staves=self.image.image_copy()
# Solution by toom (*not* equivalent to Fujinaga):
staves.filter_narrow_runs(int(1.5 * self.staffspace_height), 'black')
# Fujinaga removes short cc's, assuming a wide distance
# between noteheads/fretsymbols:
#staves.xor_image(tall_runs, True)
#for c in staves.cc_analysis:
# if c.ncols < staffspace_height:
# c.fill_white()
#staves.save_tiff("staves.tiff")
# use external class for staff line finding
self.stafffinder.find_staves(num_lines=num_lines, preprocessing=2)
# remove the stafflines
self.image.xor_image(staves, True)
#self.image.save_tiff("staves-xor-orig.tiff")
# remove remaining speckles from staff edge
# [Possible improvement (CD):
# remove only shortruns/ccs close to staff positions]
self.image.filter_short_runs(int(self.staffline_height / 3.0 + 0.5), 'black')
#for c in self.image.cc_analysis():
# if c.nrows <= self.staffline_height * 0.5:
# c.fill_white()
#self.image.despeckle(self.staffline_height)
# copy over previously saved stuff
self.image.or_image(tall_runs, True)
# isolate remaining thin staff filaments
filaments=self.image.image_copy()
#rgb=self.image.to_rgb()
# subtract all tall runs in original image so that remaining
# thin filaments are isolated
tall_runs=orig_image.image_copy()
tall_runs.filter_short_runs(int(self.staffline_height * 2), 'black')
filaments.subtract_images(tall_runs, True)
#rgb.highlight(filaments, RGBPixel(255, 0, 0))
for c in filaments.cc_analysis():
if c.nrows <= self.staffline_height*0.8:
pass
elif c.nrows < self.staffline_height * 1.0 and \
c.ncols > c.nrows * 2:
pass
else:
#rgb.highlight(c, RGBPixel(0, 255, 0))
c.fill_white()
#rgb.save_PNG("filaments.png")
self.image.subtract_images(filaments, True)
#self.image.despeckle(self.staffline_height*2)
del staves
del tall_runs
del filaments
del orig_image
######################################################################
# get_staffpos
#
# Christoph Dalitz
#
def get_staffpos(self, x=0):
"""Returns the y-positions of all staff lines at a given x-position.
Can only be called *after* ``remove_staves``.
Signature:
``get_staffpos(x=0)``
with
*x*:
This parameter has no effect, because the staffline is assumed to
be horizontal.
The return value is a list of `StaffObj`__.
.. __: gamera.toolkits.musicstaves.musicstaves.StaffObj.html#staffobj
"""
if not self.__staffobjlist and self.stafffinder.linelist != None:
self.__staffobjlist = []
for i,staff in enumerate(self.stafffinder.linelist):
if len(staff) > 0:
so = StaffObj()
so.staffno = i+1
so.yposlist=[avg.average_y for avg in \
[line.to_average() for line in staff]]
so.staffrect = Rect(Point(so.yposlist[0],staff[0].left_x),\
Point(so.yposlist[-1],staff[-1].right_x))
self.__staffobjlist.append(so)
return self.__staffobjlist
