python-mbtiles2compactcache

(credits: https://github.com/Esri/raster-tiles-compactcache)

Compact Cache V2 sample code

mbtiles2compactcache.py

Convert individual .mbtile files to the Esri Compact Cache V2 format bundles. It only builds individual bundles, not a completely functional cache.

While operational, this code is only provided as an example of how a bundle file is created and updated. This Python script takes two arguments, the input mbtile folder and the output folder. It assumes that the input folder contains mbtile files of the form: \<level#>.mbtile.

The script does not check the input tile format, and assumes that all the files under the source contain valid SQLLite databases with tiles in MBTiles format. The algorithm loops over files, inserting each tile in the appropriate bundle. It keeps one bundle open in case the next tile fits in the same bundle. In most cases this combination results in good performance.

The sample_mbtiles folder contains example MBTiles the form of SQLite databases for the single zoom levels for the first three level of the Federal Agency for Cartography and Geodesy - TopPlusOpen cache in Web Mercator projection. The [sample_cache] (../sample_cache) folder contains a Compact Cache V2 cache produced from these individual mbtiles using the mbtiles2compactcache.py script. The commands used to generate the bundles for each level are:

RGB processing:

python sample_code\mbtiles2compactcache.py -i sample_mbtiles -o sample_cache\_alllayers

Grayscale processing:

python sample_code\mbtiles2compactcache.py -i sample_mbtiles -o sample_cache\_alllayers -g

Documentation and sample code for Esri Compact Cache V2 format

The Compact Cache V2 is the current file format used by ArcGIS to store raster tiles. The Compact Cache V2 stores multiple tiles in a single file called a bundle. The bundle file structure is very simple and optimized for quick access, the result being improved performance over other alternative formats.

	Col 0	Col 1
Row 0	Row 0 Col 0	Row 0 Col 1
Row 1	Row 1 Col 0	Row 1 Col 1

Content

This repository contains documentation, a sample cache and a Python 2.x code example of how to build Compact Cache V2 bundles from MBTiles.

Licensing

Copyright 2018 Esri Germany GmbH

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.