Class: QgsRasterDataProvider

class qgis.core.QgsRasterDataProvider

Bases: QgsDataProvider, QgsRasterInterface

QgsRasterDataProvider(uri: str, providerOptions: QgsDataProvider.ProviderOptions = QgsDataProvider.ProviderOptions(), flags: Union[QgsDataProvider.ReadFlags, QgsDataProvider.ReadFlag] = QgsDataProvider.ReadFlags()) Constructor for QgsRasterDataProvider.

The uri argument gives a provider-specific uri indicating the underlying data source and it’s parameters.

The options argument specifies generic provider options and since QGIS 3.16 creation flags are specified within the flags value.

Base class for raster data providers.

Enums

ResamplingMethod

Bases: enum.IntEnum

Methods

appendError

Add error message

bandOffset

Read band offset for raster value

bandScale

Read band scale for raster value

block

Read block of data using given extent and size.

buildPyramidList

Returns the raster layers pyramid list.

buildPyramids

Create pyramid overviews

childEvent

clone

rtype

QgsRasterDataProvider

colorInterpretation

Returns data type for the band specified by number

colorInterpretationName

param bandNo

colorName

param colorInterpretation

colorTable

param bandNo

connectNotify

copyBaseSettings

Copy member variables from other raster data provider.

create

Creates a new dataset with mDataSourceURI

customEvent

dataTimestamp

Current time stamp of data source

dataType

Returns data type for the band specified by number

disconnectNotify

dpi

Returns the dpi of the output device.

enableProviderResampling

Enable or disable provider-level resampling.

extent

rtype

QgsRectangle

fields

Returns the fields of the raster layer for data providers that expose them, the default implementation returns an empty list.

getLegendGraphicFetcher

Returns a new image downloader for the raster legend.

hasPyramids

Returns True if raster has at least one populated histogram.

htmlMetadata

Returns metadata in a format suitable for feeding directly into a subset of the GUI raster properties “Metadata” tab.

identify

Identify raster value(s) found on the point position.

identifyFormatFromName

param formatName

identifyFormatLabel

param format

identifyFormatName

param format

identifyFormatToCapability

param format

ignoreExtents

Returns True if the extents reported by the data provider are not reliable and it’s possible that there is renderable content outside of these extents.

initHistogram

Fill in histogram defaults if not specified

initStatistics

Fill in statistics defaults if not specified

isEditable

Checks whether the provider is in editing mode, i.e. raster write operations will be accepted.

isProviderResamplingEnabled

Returns whether provider-level resampling is enabled.

isSignalConnected

lastError

Returns the verbose error text for the last error in this provider

lastErrorFormat

Returns the format of the error text for the last error in this provider

lastErrorTitle

Returns the caption error text for the last error in this provider

maxOversampling

Returns maximum oversampling factor for zoomed-out operations.

nativeResolutions

Returns a list of native resolutions if available, i.e. map units per pixel at which the raster source was originally created.

providerCapabilities

Returns flags containing the supported capabilities of the data provider.

pyramidResamplingMethods

Returns a list of pyramid resampling method name and label pairs for given provider

readXml

param filterElem

receivers

reload

Reload data (data could change)

remove

Remove dataset

sample

Samples a raster value from the specified band found at the point position.

sender

senderSignalIndex

setDpi

Sets the output device resolution.

setEditable

Turns on/off editing mode of the provider.

setError

Sets error message

setInput

It makes no sense to set input on provider */

setMaxOversampling

Sets maximum oversampling factor for zoomed-out operations.

setNoDataValue

Set no data value on created dataset

setUseSourceNoDataValue

Sets the source nodata value usage

setUserNoDataValue

param bandNo

setZoomedInResamplingMethod

Set resampling method to apply for zoomed-in operations.

setZoomedOutResamplingMethod

Set resampling method to apply for zoomed-out operations.

sourceDataType

Returns source data type for the band specified by number, source data type may be shorter than dataType

sourceHasNoDataValue

Returns True if source band has no data value

sourceNoDataValue

Value representing no data value.

stepHeight

Step height for raster iterations.

stepWidth

Step width for raster iterations.

subLayers

Returns the sublayers of this layer - useful for providers that manage their own layers, such as WMS

supportsLegendGraphic

Returns whether the provider supplies a legend graphic

temporalCapabilities

rtype

QgsRasterDataProviderTemporalCapabilities

timerEvent

timestamp

Time stamp of data source in the moment when data/metadata were loaded by provider

transformCoordinates

Transforms coordinates between source image coordinate space [0..width]x[0..height] and layer coordinate space (georeferenced coordinates).

useSourceNoDataValue

Returns the source nodata value usage

userNoDataValues

Returns a list of user no data value ranges.

userNoDataValuesContains

Returns True if user no data contains value

validateCreationOptions

Validates creation options for a specific dataset and destination format.

validatePyramidsConfigOptions

Validates pyramid creation options for a specific dataset and destination format

write

Writes into the provider datasource

writeBlock

Writes pixel data from a raster block into the provider data source.

writeXml

param doc

zoomedInResamplingMethod

Returns resampling method for zoomed-in operations.

zoomedOutResamplingMethod

Returns resampling method for zoomed-out operations.

Signals

statusChanged

Emit a message to be displayed on status bar, usually used by network providers (WMS,WCS)

Attributes

NoProviderCapabilities

ProviderHintBenefitsFromResampling

ProviderHintCanPerformProviderResampling

ReadLayerMetadata

TransformImageToLayer

TransformLayerToImage

WriteLayerMetadata

NoProviderCapabilities = 0
class ProviderCapabilities

Bases: sip.wrapper

QgsRasterDataProvider.ProviderCapabilities(Union[QgsRasterDataProvider.ProviderCapabilities, QgsRasterDataProvider.ProviderCapability]) QgsRasterDataProvider.ProviderCapabilities(QgsRasterDataProvider.ProviderCapabilities)

class ProviderCapability

Bases: int

ProviderHintBenefitsFromResampling = 8
ProviderHintCanPerformProviderResampling = 16
ReadLayerMetadata = 2
class ResamplingMethod(value)

Bases: enum.IntEnum

Resampling method for provider-level resampling.

New in version 3.16.

  • Nearest: Nearest-neighbour resamplikng

  • Bilinear: Bilinear resamplikng

  • Cubic: Bicubic resamplikng

Bilinear = 1
Cubic = 2
Nearest = 0
TransformImageToLayer = 0
TransformLayerToImage = 1
class TransformType

Bases: int

WriteLayerMetadata = 4
appendError(self, message: QgsErrorMessage)

Add error message

bandOffset(self, bandNo: int) → float

Read band offset for raster value

New in version 2.3.

Parameters

bandNo (int) –

Return type

float

bandScale(self, bandNo: int) → float

Read band scale for raster value

New in version 2.3.

Parameters

bandNo (int) –

Return type

float

block(self, bandNo: int, boundingBox: QgsRectangle, width: int, height: int, feedback: QgsRasterBlockFeedback = None)QgsRasterBlock

Read block of data using given extent and size.

Parameters
Return type

QgsRasterBlock

buildPyramidList(self, overviewList: Iterable[int] = []) → List[QgsRasterPyramid]

Returns the raster layers pyramid list.

Parameters

overviewList (Iterable[int] = []) – used to construct the pyramid list (optional), when empty the list is defined by the provider. A pyramid list defines the POTENTIAL pyramids that can be in a raster. To know which of the pyramid layers ACTUALLY exists you need to look at the existsFlag member in each struct stored in the list.

Return type

List[QgsRasterPyramid]

buildPyramids(self, pyramidList: Iterable[QgsRasterPyramid], resamplingMethod: str = '', format: QgsRaster.RasterPyramidsFormat = QgsRaster.PyramidsGTiff, configOptions: Iterable[str] = [], feedback: QgsRasterBlockFeedback = None) → str

Create pyramid overviews

Parameters
  • pyramidList (Iterable[QgsRasterPyramid]) –

  • resamplingMethod (str = '') –

  • format (QgsRaster.RasterPyramidsFormat = QgsRaster.PyramidsGTiff) –

  • configOptions (Iterable[str] = []) –

  • feedback (QgsRasterBlockFeedback = None) –

Return type

str

childEvent(self, QChildEvent)
clone(self)QgsRasterDataProvider
Return type

QgsRasterDataProvider

colorInterpretation(self, bandNo: int) → int

Returns data type for the band specified by number

Parameters

bandNo (int) –

Return type

int

colorInterpretationName(self, bandNo: int) → str
Parameters

bandNo (int) –

Return type

str

colorName(self, colorInterpretation: int) → str
Parameters

colorInterpretation (int) –

Return type

str

colorTable(self, bandNo: int) → List[QgsColorRampShader.ColorRampItem]
Parameters

bandNo (int) –

Return type

List[QgsColorRampShader.ColorRampItem]

connectNotify(self, QMetaMethod)
copyBaseSettings(self, other: QgsRasterDataProvider)

Copy member variables from other raster data provider. Useful for implementation of clone() method in subclasses

Parameters

other (QgsRasterDataProvider) –

create(providerKey: str, uri: str, format: str, nBands: int, type: Qgis.DataType, width: int, height: int, crs: QgsCoordinateReferenceSystem, createOptions: Iterable[str] = []) → Tuple[QgsRasterDataProvider, float]

Creates a new dataset with mDataSourceURI

Parameters
  • providerKey (str) –

  • uri (str) –

  • format (str) –

  • nBands (int) –

  • type (Qgis.DataType) –

  • width (int) –

  • height (int) –

  • crs (QgsCoordinateReferenceSystem) –

  • createOptions (Iterable[str] = []) –

Return type

Tuple[QgsRasterDataProvider, float]

customEvent(self, QEvent)
dataTimestamp(self) → QDateTime

Current time stamp of data source

Return type

QDateTime

dataType(self, bandNo: int)Qgis.DataType

Returns data type for the band specified by number

Parameters

bandNo (int) –

Return type

Qgis.DataType

disconnectNotify(self, QMetaMethod)
dpi(self) → int

Returns the dpi of the output device.

Return type

int

enableProviderResampling(self, enable: bool) → bool

Enable or disable provider-level resampling.

Return type

bool

Returns

True if success

New in version 3.16.

Parameters

enable (bool) –

extent(self)QgsRectangle
Return type

QgsRectangle

fields(self)QgsFields

Returns the fields of the raster layer for data providers that expose them, the default implementation returns an empty list.

New in version 3.14.

Return type

QgsFields

getLegendGraphicFetcher(self, mapSettings: QgsMapSettings)QgsImageFetcher

Returns a new image downloader for the raster legend.

Parameters

mapSettings (QgsMapSettings) – map settings for legend providers supporting contextual legends.

Return type

QgsImageFetcher

Returns

a download handler or None if the provider does not support legend at all. Ownership of the returned object is transferred to caller.

New in version 2.8.

hasPyramids(self) → bool

Returns True if raster has at least one populated histogram.

Return type

bool

htmlMetadata(self) → str

Returns metadata in a format suitable for feeding directly into a subset of the GUI raster properties “Metadata” tab.

Return type

str

identify(self, point: QgsPointXY, format: QgsRaster.IdentifyFormat, boundingBox: QgsRectangle = QgsRectangle(), width: int = 0, height: int = 0, dpi: int = 96)QgsRasterIdentifyResult

Identify raster value(s) found on the point position. The context parameters extent, width and height are important to identify on the same zoom level as a displayed map and to do effective caching (WCS). If context params are not specified the highest resolution is used. capabilities() may be used to test if format is supported by provider. Values are set to ‘no data’ or empty string if point is outside data source extent.

Parameters
  • point (QgsPointXY) – coordinates in data source CRS

  • format (QgsRaster.IdentifyFormat) – result format

  • boundingBox (QgsRectangle = QgsRectangle()) – context bounding box

  • width (int = 0) – context width

  • height (int = 0) – context height

  • dpi (int = 96) – context dpi

Return type

QgsRasterIdentifyResult

Returns

QgsRaster.IdentifyFormatValue: map of values for each band, keys are band numbers (from 1). QgsRaster.IdentifyFormatFeature: map of QgsRasterFeatureList for each sublayer QgsRaster.IdentifyFormatHtml: map of HTML strings for each sublayer (WMS). Empty if failed or there are no results.

Note

The arbitraryness of the returned document is enforced by WMS standards up to at least v1.3.0

See also

sample()

identifyFormatFromName(formatName: str)QgsRaster.IdentifyFormat
Parameters

formatName (str) –

Return type

QgsRaster.IdentifyFormat

identifyFormatLabel(format: QgsRaster.IdentifyFormat) → str
Parameters

format (QgsRaster.IdentifyFormat) –

Return type

str

identifyFormatName(format: QgsRaster.IdentifyFormat) → str
Parameters

format (QgsRaster.IdentifyFormat) –

Return type

str

identifyFormatToCapability(format: QgsRaster.IdentifyFormat)QgsRasterInterface.Capability
Parameters

format (QgsRaster.IdentifyFormat) –

Return type

QgsRasterInterface.Capability

ignoreExtents(self) → bool

Returns True if the extents reported by the data provider are not reliable and it’s possible that there is renderable content outside of these extents.

New in version 3.10.0.

Return type

bool

initHistogram(self, histogram: QgsRasterHistogram, bandNo: int, binCount: int, minimum: object = Py_None, maximum: object = Py_None, boundingBox: QgsRectangle = QgsRectangle(), sampleSize: int = 0, includeOutOfRange: bool = False)

Fill in histogram defaults if not specified

Note

the parameters are the same as in histogram()

initStatistics(self, statistics: QgsRasterBandStats, bandNo: int, stats: int = QgsRasterBandStats.All, boundingBox: QgsRectangle = QgsRectangle(), binCount: int = 0)

Fill in statistics defaults if not specified

isEditable(self) → bool

Checks whether the provider is in editing mode, i.e. raster write operations will be accepted. By default providers are not editable. Use setEditable() method to enable/disable editing.

See also

setEditable()

New in version 3.0.

Return type

bool

isProviderResamplingEnabled(self) → bool

Returns whether provider-level resampling is enabled.

Note

Resampling is effective only if zoomedInResamplingMethod() and/or zoomedOutResamplingMethod() return non-nearest resampling.

New in version 3.16.

Return type

bool

isSignalConnected(self, QMetaMethod) → bool
lastError(self) → str

Returns the verbose error text for the last error in this provider

If an operation returns 0 (e.g. draw()), this function returns the text of the error associated with the failure. Interactive users of this provider can then, for example, call a QMessageBox to display the contents.

Return type

str

lastErrorFormat(self) → str

Returns the format of the error text for the last error in this provider

Return type

str

lastErrorTitle(self) → str

Returns the caption error text for the last error in this provider

If an operation returns 0 (e.g. draw()), this function returns the text of the error associated with the failure. Interactive users of this provider can then, for example, call a QMessageBox to display the contents.

Return type

str

maxOversampling(self) → float

Returns maximum oversampling factor for zoomed-out operations.

New in version 3.16.

Return type

float

nativeResolutions(self) → List[float]

Returns a list of native resolutions if available, i.e. map units per pixel at which the raster source was originally created.

Resolutions are calculated in the provider’s crs().

New in version 3.8.0.

Return type

List[float]

providerCapabilities(self)QgsRasterDataProvider.ProviderCapabilities

Returns flags containing the supported capabilities of the data provider.

New in version 3.0.

Return type

QgsRasterDataProvider.ProviderCapabilities

pyramidResamplingMethods(providerKey: str) → List[Tuple[str, str]]

Returns a list of pyramid resampling method name and label pairs for given provider

Parameters

providerKey (str) –

Return type

List[Tuple[str, str]]

readXml(self, filterElem: QDomElement)
Parameters

filterElem (QDomElement) –

receivers(self, PYQT_SIGNAL) → int
reload(self) → bool

Reload data (data could change)

Return type

bool

remove(self) → bool

Remove dataset

Return type

bool

sample(self, point: QgsPointXY, band: int, boundingBox: QgsRectangle = QgsRectangle(), width: int = 0, height: int = 0, dpi: int = 96) → Tuple[float, bool]

Samples a raster value from the specified band found at the point position. The context parameters boundingBox, width and height are important to identify on the same zoom level as a displayed map and to do effective caching (WCS). If context params are not specified the highest resolution is used.

If ok is specified and the point is outside data source extent, or an invalid band number was specified, then ok will be set to False. In this case the function will return a NaN value.

See also

identify()

New in version 3.4.

Parameters
  • point (QgsPointXY) –

  • band (int) –

  • boundingBox (QgsRectangle = QgsRectangle()) –

  • width (int = 0) –

  • height (int = 0) –

  • dpi (int = 96) –

Return type

Tuple[float, bool]

sender(self) → QObject
senderSignalIndex(self) → int
setDpi(self, dpi: int)

Sets the output device resolution.

Parameters

dpi (int) –

setEditable(self, enabled: bool) → bool

Turns on/off editing mode of the provider. When in editing mode, it is possible to overwrite data of the provider using writeBlock() calls.

Return type

bool

Returns

True if the switch to/from editing mode was successful

Note

Only some providers support editing mode and even those may fail to turn the underlying data source into editing mode, so it is necessary to check the return value whether the operation was successful.

See also

isEditable()

New in version 3.0.

Parameters

enabled (bool) –

setError(self, error: QgsError)

Sets error message

setInput(self, input: QgsRasterInterface) → bool

It makes no sense to set input on provider */

Parameters

input (QgsRasterInterface) –

Return type

bool

setMaxOversampling(self, factor: float) → bool

Sets maximum oversampling factor for zoomed-out operations.

Return type

bool

Returns

True if success

New in version 3.16.

Parameters

factor (float) –

setNoDataValue(self, bandNo: int, noDataValue: float) → bool

Set no data value on created dataset

Parameters
  • bandNo (int) – band number

  • noDataValue (float) – no data value

Return type

bool

setUseSourceNoDataValue(self, bandNo: int, use: bool)

Sets the source nodata value usage

Parameters
  • bandNo (int) –

  • use (bool) –

setUserNoDataValue(self, bandNo: int, noData: Iterable[QgsRasterRange])
Parameters
setZoomedInResamplingMethod(self, method: QgsRasterDataProvider.ResamplingMethod) → bool

Set resampling method to apply for zoomed-in operations.

Return type

bool

Returns

True if success

New in version 3.16.

Parameters

method (QgsRasterDataProvider.ResamplingMethod) –

setZoomedOutResamplingMethod(self, method: QgsRasterDataProvider.ResamplingMethod) → bool

Set resampling method to apply for zoomed-out operations.

Return type

bool

Returns

True if success

New in version 3.16.

Parameters

method (QgsRasterDataProvider.ResamplingMethod) –

sourceDataType(self, bandNo: int)Qgis.DataType

Returns source data type for the band specified by number, source data type may be shorter than dataType

Parameters

bandNo (int) –

Return type

Qgis.DataType

sourceHasNoDataValue(self, bandNo: int) → bool

Returns True if source band has no data value

Parameters

bandNo (int) –

Return type

bool

sourceNoDataValue(self, bandNo: int) → float

Value representing no data value.

Parameters

bandNo (int) –

Return type

float

statusChanged

Emit a message to be displayed on status bar, usually used by network providers (WMS,WCS)

New in version 2.14: [signal]

stepHeight(self) → int

Step height for raster iterations.

See also

stepWidth()

New in version 3.0.

Return type

int

stepWidth(self) → int

Step width for raster iterations.

See also

stepHeight()

New in version 3.0.

Return type

int

subLayers(self) → List[str]

Returns the sublayers of this layer - useful for providers that manage their own layers, such as WMS

Return type

List[str]

supportsLegendGraphic(self) → bool

Returns whether the provider supplies a legend graphic

Return type

bool

temporalCapabilities(self)QgsRasterDataProviderTemporalCapabilities
Return type

QgsRasterDataProviderTemporalCapabilities

timerEvent(self, QTimerEvent)
timestamp(self) → QDateTime

Time stamp of data source in the moment when data/metadata were loaded by provider

Return type

QDateTime

transformCoordinates(self, point: QgsPoint, type: QgsRasterDataProvider.TransformType)QgsPoint

Transforms coordinates between source image coordinate space [0..width]x[0..height] and layer coordinate space (georeferenced coordinates). Often this transformation is a simple 2D affine transformation (offset and scaling), but rasters with different georeferencing methods like GCPs (ground control points) or RPCs (rational polynomial coefficients) may require a more complex transform.

If the transform fails (input coordinates are outside of the valid range or data provider does not support this functionality), an empty point is returned.

New in version 3.14.

Parameters
Return type

QgsPoint

useSourceNoDataValue(self, bandNo: int) → bool

Returns the source nodata value usage

Parameters

bandNo (int) –

Return type

bool

userNoDataValues(self, bandNo: int) → List[QgsRasterRange]

Returns a list of user no data value ranges.

Parameters

bandNo (int) –

Return type

List[QgsRasterRange]

userNoDataValuesContains(self, bandNo: int, value: float) → bool

Returns True if user no data contains value

Parameters
  • bandNo (int) –

  • value (float) –

Return type

bool

validateCreationOptions(self, createOptions: Iterable[str], format: str) → str

Validates creation options for a specific dataset and destination format.

Note

used by GDAL provider only

Note

see also validateCreationOptionsFormat() in gdal provider for validating options based on format only

Parameters
  • createOptions (Iterable[str]) –

  • format (str) –

Return type

str

validatePyramidsConfigOptions(self, pyramidsFormat: QgsRaster.RasterPyramidsFormat, configOptions: Iterable[str], fileFormat: str) → str

Validates pyramid creation options for a specific dataset and destination format

Note

used by GDAL provider only

Parameters
Return type

str

write(self, data: sip.voidptr, band: int, width: int, height: int, xOffset: int, yOffset: int) → bool

Writes into the provider datasource

Parameters
  • data (sip.voidptr) –

  • band (int) –

  • width (int) –

  • height (int) –

  • xOffset (int) –

  • yOffset (int) –

Return type

bool

writeBlock(self, block: QgsRasterBlock, band: int, xOffset: int = 0, yOffset: int = 0) → bool

Writes pixel data from a raster block into the provider data source.

This will override previously stored pixel values. It is assumed that cells in the passed raster block are aligned with the cells of the data source. If raster block does not cover the whole area of the data source, only a subset of pixels covered by the raster block will be overwritten. By default, writing of raster data starts from the first cell of the raster - it is possible to set offset in pixels by specifying non-zero xOffset and yOffset values.

Writing is supported only by some data providers. Provider has to be in editing mode in order to allow write operations.

See also

isEditable()

Return type

bool

Returns

True on success

New in version 3.0.

Parameters
  • block (QgsRasterBlock) –

  • band (int) –

  • xOffset (int = 0) –

  • yOffset (int = 0) –

writeXml(self, doc: QDomDocument, parentElem: QDomElement)
Parameters
  • doc (QDomDocument) –

  • parentElem (QDomElement) –

zoomedInResamplingMethod(self)QgsRasterDataProvider.ResamplingMethod

Returns resampling method for zoomed-in operations.

New in version 3.16.

Return type

QgsRasterDataProvider.ResamplingMethod

zoomedOutResamplingMethod(self)QgsRasterDataProvider.ResamplingMethod

Returns resampling method for zoomed-out operations.

New in version 3.16.

Return type

QgsRasterDataProvider.ResamplingMethod