本文整理汇总了Python中qgis.core.QgsRasterLayer.previewAsImage方法的典型用法代码示例。如果您正苦于以下问题:Python QgsRasterLayer.previewAsImage方法的具体用法?Python QgsRasterLayer.previewAsImage怎么用?Python QgsRasterLayer.previewAsImage使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类qgis.core.QgsRasterLayer
的用法示例。
在下文中一共展示了QgsRasterLayer.previewAsImage方法的3个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: testSetDataSource
# 需要导入模块: from qgis.core import QgsRasterLayer [as 别名]
# 或者: from qgis.core.QgsRasterLayer import previewAsImage [as 别名]
def testSetDataSource(self):
"""Test change data source"""
temp_dir = QTemporaryDir()
options = QgsDataProvider.ProviderOptions()
myPath = os.path.join(unitTestDataPath('raster'),
'band1_float32_noct_epsg4326.tif')
myFileInfo = QFileInfo(myPath)
myBaseName = myFileInfo.baseName()
layer = QgsRasterLayer(myPath, myBaseName)
renderer = QgsSingleBandGrayRenderer(layer.dataProvider(), 2)
image = layer.previewAsImage(QSize(400, 400))
self.assertFalse(image.isNull())
self.assertTrue(image.save(os.path.join(temp_dir.path(), 'expected.png'), "PNG"))
layer.setDataSource(myPath.replace('4326.tif', '4326-BAD_SOURCE.tif'), 'bad_layer', 'gdal', options)
self.assertFalse(layer.isValid())
image = layer.previewAsImage(QSize(400, 400))
self.assertTrue(image.isNull())
layer.setDataSource(myPath.replace('4326-BAD_SOURCE.tif', '4326.tif'), 'bad_layer', 'gdal', options)
self.assertTrue(layer.isValid())
image = layer.previewAsImage(QSize(400, 400))
self.assertFalse(image.isNull())
self.assertTrue(image.save(os.path.join(temp_dir.path(), 'actual.png'), "PNG"))
self.assertTrue(filecmp.cmp(os.path.join(temp_dir.path(), 'actual.png'), os.path.join(temp_dir.path(), 'expected.png')), False)
示例2: replaceImage
# 需要导入模块: from qgis.core import QgsRasterLayer [as 别名]
# 或者: from qgis.core.QgsRasterLayer import previewAsImage [as 别名]
def replaceImage(self, filepath, title):
self.title = title
self.filepath = filepath
# set custom properties
self.setCustomProperty("title", title)
self.setCustomProperty("filepath", self.filepath)
self.setName(title)
fileInfo = QFileInfo(filepath)
ext = fileInfo.suffix()
if ext == "pdf":
s = QSettings()
oldValidation = s.value("/Projections/defaultBehavior")
s.setValue("/Projections/defaultBehavior", "useGlobal") # for not asking about crs
path = fileInfo.filePath()
baseName = fileInfo.baseName()
layer = QgsRasterLayer(path, baseName)
self.image = layer.previewAsImage(QSize(layer.width(), layer.height()))
s.setValue("/Projections/defaultBehavior", oldValidation)
else:
reader = QImageReader(filepath)
self.image = reader.read()
self.repaint()
示例3: initializeLayer
# 需要导入模块: from qgis.core import QgsRasterLayer [as 别名]
# 或者: from qgis.core.QgsRasterLayer import previewAsImage [as 别名]
def initializeLayer(self, screenExtent=None):
if self.error or self.initialized or self.initializing:
return
if self.filepath is not None:
# not safe...
self.initializing = True
filepath = self.getAbsoluteFilepath()
if not os.path.exists(filepath):
# TODO integrate with BadLayerHandler ?
loadErrorDialog = LoadErrorDialog(filepath)
result = loadErrorDialog.exec_()
if result == 1:
# absolute
filepath = loadErrorDialog.lineEditImagePath.text()
# to relative if needed
self.filepath = utils.toRelativeToQGS(filepath)
self.setCustomProperty("filepath", self.filepath)
QgsProject.instance().setDirty(True)
else:
self.error = True
del loadErrorDialog
fileInfo = QFileInfo(filepath)
ext = fileInfo.suffix()
if ext == "pdf":
s = QSettings()
oldValidation = s.value("/Projections/defaultBehavior")
s.setValue("/Projections/defaultBehavior", "useGlobal") # for not asking about crs
path = fileInfo.filePath()
baseName = fileInfo.baseName()
layer = QgsRasterLayer(path, baseName)
self.image = layer.previewAsImage(QSize(layer.width(),layer.height()))
s.setValue("/Projections/defaultBehavior", oldValidation)
else:
reader = QImageReader(filepath)
self.image = reader.read()
self.initialized = True
self.initializing = False
self.setupCrs()
if screenExtent:
# constructor called from AddLayer action
# if not, layer loaded from QGS project file
# check if image already has georef info
# use GDAL
dataset = gdal.Open(filepath, gdal.GA_ReadOnly)
georef = None
if dataset:
georef = dataset.GetGeoTransform()
if georef and not self.is_default_geotransform(georef):
self.initializeExistingGeoreferencing(dataset, georef)
else:
# init to default params
self.setCenter(screenExtent.center())
self.setRotation(0.0)
sw = screenExtent.width()
sh = screenExtent.height()
self.resetScale(sw, sh)
self.commitTransformParameters()