openstreetmap / openstreetmap/mod_tile
getting blank tile while using mod_tile with mapnik to serve geotiff file
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- C++
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Description
Hi, I stuck in one issue where i have geotiff files and i want to use mod_tile but problem is after trying everything i am still getting balnk tile in api response but i tride to generate same tile using python and mapnik i am able to do so.
i am adding all information here
- mapnik.xml
<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
<Style name="raster-style">
<Rule>
<RasterSymbolizer opacity="1.0" scaling="bilinear">
<Colorizer type="linear" epsilon="0.01">
<stop color="black" value="0"/>
<stop color="white" value="255"/>
</Colorizer>
</RasterSymbolizer>
</Rule>
</Style>
<Layer name="GeoTIFF" status="true" srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
<StyleName>raster-style</StyleName>
<Datasource>
<Parameter name="type">gdal</Parameter>
<Parameter name="file">/usr/share/renderd/mod_tile_poc/AQ.tif</Parameter>
<Parameter name="estimate_extent">true</Parameter>
<Parameter name="log">/usr/share/renderd/mod_tile_poc/mapnik.log</Parameter>
<Parameter name="debug">debug</Parameter>
</Datasource>
</Layer>
</Map>
- /etc/renderd.conf
[renderd]
pid_file=/run/renderd/renderd.pid
socketname=/run/renderd/renderd.sock
stats_file=/run/renderd/renderd.stats
tile_dir=/var/cache/renderd/tiles
[mapnik]
font_dir=/usr/share/fonts
font_dir_recurse=0
plugins_dir=/usr/lib/mapnik/3.0/input
[default]
URI=/osm_tiles/
TILEDIR=/var/lib/mod_tile
XML=/usr/share/renderd/example-map/mapnik.xml
HOST=0.0.0.0
TILESIZE=256
[example-map]
URI=/tiles/renderd-example
XML=/usr/share/renderd/example-map/mapnik.xml
[example-map-jpg]
TYPE=jpg image/jpeg jpeg
URI=/tiles/renderd-example-jpg
XML=/usr/share/renderd/example-map/mapnik.xml
[example-map-png256]
TYPE=png image/png png256
URI=/tiles/renderd-example-png256
XML=/usr/share/renderd/example-map/mapnik.xml
[example-map-png32]
TYPE=png image/png png32
URI=/tiles/renderd-example-png32
XML=/usr/share/renderd/example-map/mapnik.xml
[example-map-webp]
TYPE=webp image/webp webp
URI=/tiles/renderd-example-webp
XML=/usr/share/renderd/example-map/mapnik.xml
- this is info about geotiff file
Driver: GTiff/GeoTIFF
Files: AQ.tiff
Size is 7220, 2810
Coordinate System is:
GEOGCRS["WGS 84",
DATUM["World Geodetic System 1984",
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
CS[ellipsoidal,2],
AXIS["geodetic latitude (Lat)",north,
ORDER[1],
ANGLEUNIT["degree",0.0174532925199433]],
AXIS["geodetic longitude (Lon)",east,
ORDER[2],
ANGLEUNIT["degree",0.0174532925199433]],
ID["EPSG",4326]]
Data axis to CRS axis mapping: 2,1
Origin = (-180.500000000000000,84.099607528087063)
Pixel Size = (0.050000000000000,-0.050000000000000)
Metadata:
AREA_OR_POINT=Area
Image Structure Metadata:
INTERLEAVE=BAND
Corner Coordinates:
Upper Left (-180.5000000, 84.0996075) (180d30' 0.00"W, 84d 5'58.59"N)
Lower Left (-180.5000000, -56.4003925) (180d30' 0.00"W, 56d24' 1.41"S)
Upper Right ( 180.5000000, 84.0996075) (180d30' 0.00"E, 84d 5'58.59"N)
Lower Right ( 180.5000000, -56.4003925) (180d30' 0.00"E, 56d24' 1.41"S)
Center ( 0.0000000, 13.8496075) ( 0d 0' 0.01"E, 13d50'58.59"N)
Band 1 Block=7220x1 Type=Int32, ColorInterp=Gray
NoData Value=-255
Contributor guide
No contributing guide indexed for this repository
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the supplied mapnik.xml and /etc/renderd.conf, then inspect the renderd and mapnik.log paths while reproducing the blank tile response. Compare that behavior with the Python-generated tile and the GeoTIFF metadata shown in the issue; done means the configured tile endpoint returns a rendered tile rather than a blank response.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- apache, python
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100