Licensing

[中文]

This chapter is the single reference for how licensing works across ESP-VISION. It is developer guidance, not legal advice; the license text and source-file headers for the exact version in use remain authoritative.

ESP-VISION’s own code (platform/, most of modules/, boards/, and build files) is released under Apache License 2.0, recorded in the repository-level LICENSE. Vendored and third-party code keeps the license declared by its own source files, SPDX identifiers, or upstream license; the repository-level LICENSE does not override or replace those.

License Inventory

The following table lists the direct dependencies most relevant to redistribution. It is not a complete inventory of transitive dependencies.

Project or code	Local path	Role in ESP-VISION	License
MicroPython v1.28.0	lib/micropython	Python runtime and ESP32 port baseline	MIT
micropython-ulab 6.12	lib/ulab	Array and numerical computing	MIT
OpenMV imlib subset	components/imlib	Image processing and drawing algorithms	MIT, with separately licensed files
OpenMV Python binding code	modules/py_image*, modules/py_helper*	OpenMV-style image API bindings	MIT
OpenMV AprilTag implementation	components/imlib/upstream/apriltag.c	AprilTag and rectangle detection	BSD-2-Clause
ZXing-C++ v3.0.2	lib/zxing-cpp	1D barcode reader backend	Apache-2.0
ESP-DL	Component Registry	Model inference runtime	MIT
esp_new_jpeg	Component Registry	Software JPEG codec	Espressif MIT (product-scope)
esp32-camera	Component Registry	Camera driver	Apache-2.0
ESP-IDF	External SDK	Build system, drivers, and media components	Apache-2.0

How to Interpret the Licenses

The repository-level LICENSE covers original ESP-VISION code and does not override third-party licenses:

• third-party files remain under their original licenses and retain their original copyright and license headers;

• a directory can contain multiple licenses: most imlib code is MIT while apriltag.c is BSD-2-Clause;

• permissive licenses such as Apache-2.0, MIT, and BSD generally allow combined distribution, but their copyright, license text, and notice requirements still apply;

• some Espressif components use licenses with product-scope conditions. For example, the current esp_new_jpeg license text limits use to Espressif products, so it should not be described only as unrestricted generic MIT;

• trademarks, patents, model files, and datasets may have separate terms that cannot be inferred from the source-code license.

Before distributing source or firmware, check at least:

1. the repository-level LICENSE;

2. the LICENSE in every Git submodule;

3. managed_components/*/LICENSE from the selected build;

4. SPDX identifiers, license headers, and copyright notices in modified or newly added source files;

5. provenance and terms for non-code assets such as models, fonts, and test images.

OpenMV and GPL Code Paths

Not every optional OpenMV upstream algorithm uses the same license. ESP-VISION sets OMV_NO_GPL=1 in micropython.cmake and components/imlib/CMakeLists.txt so GPL-conditioned OpenMV code paths are not compiled. This switch only describes what the default build excludes; it is not an automatic license classification for newly added files.

When changing imlib feature switches, synchronizing OpenMV upstream code, or adding algorithms, inspect each file’s license. Do not infer a license only from the directory containing the file.

Adding Third-Party Code

When adding a third-party package or source file to ESP-VISION:

1. pin a reproducible release or commit;

2. verify the license per file and its compatibility with the intended distribution;

3. preserve upstream copyright, SPDX identifiers, license text, and any required NOTICE;

4. record the source, version, local path, purpose, and license in this inventory;

5. verify that build switches actually exclude code that is not intended for distribution instead of relying on documentation alone;

6. obtain legal review before merging when licensing is unclear or imposes commercial-distribution constraints.