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Added processing algorithm to convert map to raster
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| # -*- coding: utf-8 -*- | ||
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| """ | ||
| /*************************************************************************** | ||
| QFieldSync processing provider | ||
| ------------------- | ||
| begin : 2016-10-05 | ||
| copyright : (C) 2016 by OPENGIS.ch | ||
| email : matthias@opengis.ch | ||
| ***************************************************************************/ | ||
| /*************************************************************************** | ||
| * * | ||
| * This program is free software; you can redistribute it and/or modify * | ||
| * it under the terms of the GNU General Public License as published by * | ||
| * the Free Software Foundation; either version 2 of the License, or * | ||
| * (at your option) any later version. * | ||
| * * | ||
| ***************************************************************************/ | ||
| """ | ||
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| from processing.core.outputs import OutputRaster | ||
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| from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm | ||
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| from qgis.PyQt.QtGui import QImage, QPainter | ||
| from qgis.PyQt.QtCore import QSize | ||
| from qgis.core import ( | ||
| QgsMapSettings, | ||
| QgsMapRendererCustomPainterJob, | ||
| QgsRectangle, | ||
| QgsProject, | ||
| QgsProcessingException, | ||
| QgsProcessingParameterExtent, | ||
| QgsProcessingParameterString, | ||
| QgsProcessingParameterNumber, | ||
| QgsProcessingParameterRasterLayer, | ||
| QgsProcessingOutputRasterLayer, | ||
| QgsProcessingParameterRasterDestination | ||
| ) | ||
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| import qgis | ||
| import osgeo.gdal | ||
| import os | ||
| import tempfile | ||
| import math | ||
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| __author__ = 'Matthias Kuhn' | ||
| __date__ = '2016-10-05' | ||
| __copyright__ = '(C) 2016 by OPENGIS.ch' | ||
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| # This will get replaced with a git SHA1 when you do a git archive | ||
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| __revision__ = '$Format:%H$' | ||
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| class RasterizeAlgorithm(QgisAlgorithm): | ||
| """ | ||
| """ | ||
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| # Constants used to refer to parameters and outputs. They will be | ||
| # used when calling the algorithm from another algorithm, or when | ||
| # calling from the QGIS console. | ||
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| OUTPUT_LAYER = 'OUTPUT_LAYER' | ||
| MAP_THEME = 'MAP_THEME' | ||
| LAYER = 'LAYER' | ||
| EXTENT = 'EXTENT' | ||
| TILE_SIZE = 'TILE_SIZE' | ||
| MAP_UNITS_PER_PIXEL = 'MAP_UNITS_PER_PIXEL' | ||
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| def __init__(self): | ||
| super().__init__() | ||
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| def initAlgorithm(self, config=None): | ||
| """Here we define the inputs and output of the algorithm, along | ||
| with some other properties. | ||
| """ | ||
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| # The parameters | ||
| self.addParameter( | ||
| QgsProcessingParameterString(self.MAP_THEME, | ||
| description=self.tr( | ||
| 'Map theme to render.'), | ||
| defaultValue=None, optional=True)) | ||
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| self.addParameter( | ||
| QgsProcessingParameterRasterLayer(self.LAYER, description=self.tr( | ||
| 'Layer to render. Will only be used if the map theme is not ' | ||
| 'set. ' | ||
| 'If both, map theme and layer are not ' | ||
| 'set, the current map content will be rendered.'), | ||
| optional=True)) | ||
| self.addParameter( | ||
| QgsProcessingParameterExtent(self.EXTENT, description=self.tr( | ||
| 'The minimum extent to render. Will internally be extended to ' | ||
| 'be ' | ||
| 'a multiple of the tile sizes.'))) | ||
| self.addParameter( | ||
| QgsProcessingParameterNumber(self.TILE_SIZE, self.tr('Tile size'), | ||
| defaultValue=1024)) | ||
| self.addParameter(QgsProcessingParameterNumber(self.MAP_UNITS_PER_PIXEL, | ||
| self.tr( | ||
| 'Map units per ' | ||
| 'pixel'), | ||
| defaultValue=100)) | ||
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| # We add a raster layer as output | ||
| self.addParameter(QgsProcessingParameterRasterDestination( | ||
| self.OUTPUT_LAYER, | ||
| self.tr( | ||
| 'Output layer'))) | ||
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| def name(self): | ||
| # Unique (non-user visible) name of algorithm | ||
| return 'Rasterize' | ||
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| def displayName(self): | ||
| # The name that the user will see in the toolbox | ||
| return self.tr('Convert map to raster') | ||
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| def group(self): | ||
| return self.tr('Raster tools') | ||
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| # def processAlgorithm(self, progress): | ||
| def processAlgorithm(self, parameters, context, feedback): | ||
| """Here is where the processing itself takes place.""" | ||
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| # The first thing to do is retrieve the values of the parameters | ||
| # entered by the user | ||
| map_theme = self.parameterAsString(parameters, self.MAP_THEME, context) | ||
| layer = self.parameterAsString(parameters, self.LAYER, context) | ||
| extent = self.parameterAsExtent(parameters, self.EXTENT, | ||
| context) | ||
| tile_size = self.parameterAsInt(parameters, self.TILE_SIZE, context) | ||
| mupp = self.parameterAsInt(parameters, self.MAP_UNITS_PER_PIXEL, context) | ||
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| output_layer = self.parameterAsOutputLayer(parameters, self.OUTPUT_LAYER, | ||
| context) | ||
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| # This probably affects the whole system but it's a lot nicer | ||
| osgeo.gdal.UseExceptions() | ||
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| tile_set = TileSet(map_theme, layer, extent, tile_size, mupp, output_layer, | ||
| qgis.utils.iface.mapCanvas().mapSettings()) | ||
| tile_set.render() | ||
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| return {self.OUTPUT_LAYER: output_layer} | ||
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| class TileSet(): | ||
| """ | ||
| A set of tiles /home/mario/Dropbox/workspace/marioba/QGIS/python/plugins/processing/tests/testdata/ | ||
| """ | ||
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| def __init__(self, map_theme, layer, extent, tile_size, mupp, output, | ||
| map_settings): | ||
| """ | ||
| :param map_theme: | ||
| :param extent: | ||
| :param layer: | ||
| :param tile_size: | ||
| :param mupp: | ||
| :param output: | ||
| :param map_settings: Map canvas map settings used for some fallback | ||
| values and CRS | ||
| """ | ||
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| self.extent = extent | ||
| self.mupp = mupp | ||
| self.tile_size = tile_size | ||
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| # TODO: Check if file exists and update instead? | ||
| driver = self.getDriverForFile(output) | ||
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| if not driver: | ||
| raise QgsProcessingException( | ||
| u'Could not load GDAL driver for file {}'.format(output)) | ||
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| crs = map_settings.destinationCrs() | ||
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| self.x_tile_count = math.ceil(extent.width() / mupp / tile_size) | ||
| self.y_tile_count = math.ceil(extent.height() / mupp / tile_size) | ||
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| xsize = self.x_tile_count * tile_size | ||
| ysize = self.y_tile_count * tile_size | ||
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| self.dataset = driver.Create(output, xsize, ysize, 3) # 3 bands | ||
| self.dataset.SetProjection(str(crs.toWkt())) | ||
| self.dataset.SetGeoTransform( | ||
| [extent.xMinimum(), mupp, 0, extent.yMaximum(), 0, -mupp]) | ||
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| self.image = QImage(QSize(tile_size, tile_size), QImage.Format_RGB32) | ||
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| self.settings = QgsMapSettings() | ||
| self.settings.setOutputDpi(self.image.logicalDpiX()) | ||
| self.settings.setOutputImageFormat(QImage.Format_RGB32) | ||
| self.settings.setDestinationCrs(crs) | ||
| self.settings.setOutputSize(self.image.size()) | ||
| self.settings.setFlag(QgsMapSettings.Antialiasing, True) | ||
| self.settings.setFlag(QgsMapSettings.RenderMapTile, True) | ||
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| if QgsProject.instance().mapThemeCollection().hasMapTheme(map_theme): | ||
| self.settings.setLayers( | ||
| QgsProject.instance().mapThemeCollection( | ||
|
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| ).mapThemeVisibleLayers( | ||
| map_theme)) | ||
| self.settings.setLayerStyleOverrides( | ||
| QgsProject.instance().mapThemeCollection( | ||
|
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| ).mapThemeStyleOverrides( | ||
| map_theme)) | ||
| elif layer: | ||
| self.settings.setLayers([layer]) | ||
| else: | ||
| self.settings.setLayers(map_settings.layers()) | ||
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| def render(self): | ||
| for x in range(self.x_tile_count): | ||
| for y in range(self.y_tile_count): | ||
| cur_tile = x * self.y_tile_count + y | ||
| num_tiles = self.x_tile_count * self.y_tile_count | ||
| self.renderTile(x, y) | ||
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| def renderTile(self, x, y): | ||
| """ | ||
| Render one tile | ||
| :param x: The x index of the current tile | ||
| :param y: The y index of the current tile | ||
| """ | ||
| painter = QPainter(self.image) | ||
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| self.settings.setExtent(QgsRectangle( | ||
| self.extent.xMinimum() + x * self.mupp * self.tile_size, | ||
| self.extent.yMaximum() - (y + 1) * self.mupp * self.tile_size, | ||
| self.extent.xMinimum() + (x + 1) * self.mupp * self.tile_size, | ||
| self.extent.yMaximum() - y * self.mupp * self.tile_size)) | ||
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| job = QgsMapRendererCustomPainterJob(self.settings, painter) | ||
| job.renderSynchronously() | ||
| painter.end() | ||
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| # Needs not to be deleted or Windows will kill it too early... | ||
| tmpfile = tempfile.NamedTemporaryFile(suffix='.png', delete=False) | ||
| try: | ||
| self.image.save(tmpfile.name) | ||
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| src_ds = osgeo.gdal.Open(tmpfile.name) | ||
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| self.dataset.WriteRaster(x * self.tile_size, y * self.tile_size, | ||
| self.tile_size, self.tile_size, | ||
| src_ds.ReadRaster(0, 0, self.tile_size, | ||
| self.tile_size)) | ||
| finally: | ||
| del src_ds | ||
| tmpfile.close() | ||
| os.unlink(tmpfile.name) | ||
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| def getDriverForFile(self, filename): | ||
| """ | ||
| Get the GDAL driver for a filename, based on its extension. (.gpkg, .mbtiles...) | ||
| """ | ||
| _, extension = os.path.splitext(filename) | ||
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| # If no extension is set, use .tif as default | ||
| if extension == '': | ||
| extension = '.tif' | ||
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| for i in range(osgeo.gdal.GetDriverCount()): | ||
| driver = osgeo.gdal.GetDriver(i) | ||
| if driver.GetMetadataItem('DMD_EXTENSION') == extension[1:]: | ||
| return driver |
525aeabThere was a problem hiding this comment.
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Nice feature. There's a problem when exporting a map with two layers (simple hillshade raster below a vector polygon layer with a blending mode set to multiply). Somehow, there are large black areas showing up:
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(I should have mentioned, the exported map-to-raster is the black square, I've zoomed out on the canvas to show how the canvas base raster is a light hillshade, which fails to export, and instead turns black when not overlapping a polygon layer.)