def _reopen(self, gdalobj=None):
if not gdalobj:
# assume self._obj has already been set from caller
gdalobj = self._obj
else:
self._obj = gdalobj
if self.rowCount() > gdalobj.GetOverviewCount():
_log.warning(
'unable to reopen raster band: unexpected number of overviews')
return
if VISIBLE_OVERVIEW_ITEMS:
levelsmap = dict(zip(gdalsupport.ovrLevels(gdalobj),
range(gdalobj.GetOverviewCount())))
oldlevelsmap = dict(zip(gdalsupport.ovrLevels(self._obj),
range(self._obj.GetOverviewCount())))
toremove = []
for level, index in oldlevelsmap.items():
if level not in levelsmap:
#self.removeRow(index)
toremove.append(index)
else:
item = self.GetOverview(index)
newindex = levelsmap[level]
item._reopen(gdalobj.GetOverview(newindex))
for index in toremove:
self.takeRow(index)
for level, index in levelsmap.items():
if level in oldlevelsmap:
continue
ovr = gdalobj.GetOverview(index)
item = OverviewItem(ovr)
if not item.text():
text = 'Overview'
if QtWidgets.qApp is not None:
text = QtWidgets.qApp.tr(text)
description = '%s n. %d' % (text, index)
item.setText(description)
item.setToolTip(description)
self.insertRow(index, item)
# @TODO: complete
#self.sortChildren(0, QtCore.Qt.AscendngOrder)
self._obj = gdalobj
self.model().itemChanged.emit(self)
def setItem(self, item):
assert item.backend == 'gdalbackend'
self.graphicsview.setUpdatesEnabled(False)
try:
self.reset()
try:
level = gdalsupport.ovrLevelForSize(item, self.OVRMAXSIZE)
# @NOTE: use GREATER for overview level to ensure an overview
# size smaller than OVRMAXSIZE
ovrindex = gdalsupport.ovrBestIndex(item, level, 'GREATER')
except gdalsupport.MissingOvrError:
_log.info('no overview available or available overviews are '
'too large')
return
scene = item.scene
self.graphicsview.setScene(scene)
self.graphicsview.setSceneRect(scene.sceneRect())
if not self.graphicsview.autoscale:
ovrlevel = gdalsupport.ovrLevels(item)[ovrindex]
matrix = QtGui.QMatirx3x3(ovrlevel, 0, 0, ovrlevel, 0, 0)
self.graphicsview.setMatrix(matrix)
else:
self.graphicsview.fitInView()
self.updateMainViewBox()
finally:
self.graphicsview.setUpdatesEnabled(True)
self.graphicsview.update()
def target_levels(self, dataset):
if self._band is not None:
band = self._band
else:
band = dataset.GetRasterBand(1)
oldlevels = []
estep = 3
threshold = 0.1
if band.GetOverviewCount():
oldlevels = gdalsupport.ovrLevels(band)
if set(oldlevels).issuperset((2, 4)):
estep = 2
threshold = 1.1
# @NOTE: use dataset for levels computation because the
# IMAGE_STRUCTURE metadata are not propagated from
# CachedDatasetItem to raster bands
levels = gdalsupport.ovrComputeLevels(dataset,
estep=estep,
threshold=threshold)
# @NOTE: the GDAL band info is configured to force recomputation of
# all levels checked
if levels:
levels.extend(oldlevels)
levels.sort()
return levels
def setItem(self, item):
assert item.backend == 'gdalbackend'
self.graphicsview.setUpdatesEnabled(False)
try:
self.reset()
try:
level = gdalsupport.ovrLevelForSize(item, self.OVRMAXSIZE)
# @NOTE: use GREATER for overview level to ensure an overview
# size smaller than OVRMAXSIZE
ovrindex = gdalsupport.ovrBestIndex(item, level, 'GREATER')
except gdalsupport.MissingOvrError:
logging.info('no overview available or available overviews '
'are too large')
return
scene = item.scene
self.graphicsview.setScene(scene)
self.graphicsview.setSceneRect(scene.sceneRect())
if not self.graphicsview.autoscale:
ovrlevel = gdalsupport.ovrLevels(item)[ovrindex]
matrix = QtCore.QMatirx(ovrlevel, 0, 0, ovrlevel, 0, 0)
self.graphicsview.setMatrix(matrix)
else:
self.graphicsview.fitInView()
self.updateMainViewBox()
finally:
self.graphicsview.setUpdatesEnabled(True)
self.graphicsview.update()
def target_levels(self, dataset):
if self._band is not None:
band = self._band
else:
band = dataset.GetRasterBand(1)
oldlevels = []
estep = 3
threshold = 0.1
if band.GetOverviewCount():
oldlevels = gdalsupport.ovrLevels(band)
if set(oldlevels).issuperset((2, 4)):
estep = 2
threshold = 1.1
# @NOTE: use dataset for levels computation because the
# IMAGE_STRUCTURE metadata are not propagated from
# CachedDatasetItem to raster bands
levels = gdalsupport.ovrComputeLevels(dataset, estep=estep, threshold=threshold)
# @NOTE: the GDAL band info is configured to force recomputation of
# all levels checked
if levels:
levels.extend(oldlevels)
levels.sort()
return levels
def _bestOvrLevel(band, levelOfDetail):
ovrlevel = 1
ovrindex = None
if band.GetOverviewCount() > 0:
if levelOfDetail <= 0:
reqlevel = 1.
else:
reqlevel = 1. / levelOfDetail
try:
ovrindex = gdalsupport.ovrBestIndex(band, reqlevel)
except gdalsupport.MissingOvrError:
pass
else:
ovrlevel = gdalsupport.ovrLevels(band)[ovrindex]
if abs(reqlevel - 1) < abs(reqlevel - ovrlevel):
ovrlevel = 1
ovrindex = None
else:
band = band.GetOverview(ovrindex)
return band, ovrlevel, ovrindex
def _bestOvrLevel(band, levelOfDetail):
ovrlevel = 1
ovrindex = None
if band.GetOverviewCount() > 0:
if levelOfDetail <= 0:
reqlevel = 1.
else:
reqlevel = 1. / levelOfDetail
try:
ovrindex = gdalsupport.ovrBestIndex(band, reqlevel)
except gdalsupport.MissingOvrError:
pass
else:
ovrlevel = gdalsupport.ovrLevels(band)[ovrindex]
if abs(reqlevel - 1) < abs(reqlevel - ovrlevel):
ovrlevel = 1
ovrindex = None
else:
band = band.GetOverview(ovrindex)
return band, ovrlevel, ovrindex
