mapchete.formats.default.png_hillshade module

Special PNG process output for hillshades.

Writes inverted hillshade into alpha channel of black image, so that hillshade can be used as overlay over other data.

output configuration parameters

mandatory

path: string

output directory

optional

nodata: integer or float

nodata value used for writing

class mapchete.formats.default.png_hillshade.OutputDataReader(output_params, **kwargs)

Bases: TileDirectoryOutputReader

PNG_hillshade output class.

Parameters

output_paramsdictionary

output parameters from Mapchete file

Attributes

pathstring

path to output directory

file_extensionstring

file extension for output files (.tif)

output_paramsdictionary

output parameters from Mapchete file

old_band_numbool

in prior versions, 4 channels (3x gray 1x alpha) were written, now 2 channels (1x gray, 1x alpha)

pixelbufferinteger

buffer around output tiles

pyramidtilematrix.TilePyramid

output TilePyramid

crsrasterio.crs.CRS

object describing the process coordinate reference system

sridstring

spatial reference ID of CRS (e.g. “{‘init’: ‘epsg:4326’}”)

METADATA = {'data_type': 'raster', 'driver_name': 'PNG_hillshade', 'mode': 'w'}

empty(process_tile)

Return empty data.

Parameters

process_tileBufferedTile

must be member of process TilePyramid

Returns

empty dataarray or list

empty array with correct data type for raster data or empty list for vector data

for_web(data)

Convert data to web output.

Parameters

dataarray

Returns

MemoryFile(), MIME type

is_valid_with_config(config)

Check if output format is valid with other process parameters.

Parameters

configdictionary

output configuration parameters

Returns

is_validbool

profile(tile=None)

Create a metadata dictionary for rasterio.

Parameters

tileBufferedTile

Returns

metadatadictionary

output profile dictionary used for rasterio.

read(output_tile, **kwargs)

Read existing process output.

Parameters

output_tileBufferedTile

must be member of output TilePyramid

Returns

process outputBufferedTile with appended data

class mapchete.formats.default.png_hillshade.OutputDataWriter(output_params, **kwargs)

Bases: OutputDataWriter, OutputDataReader

METADATA = {'data_type': 'raster', 'driver_name': 'PNG_hillshade', 'mode': 'w'}

write(process_tile, data)

Write data from process tiles into PNG file(s).

Parameters

process_tileBufferedTile

must be member of process TilePyramid