Python API for Blender's internal image functions #54272

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Campbell Barton · 2018-03-08T14:46:00+01:00

Campbell Barton commented

2018-03-08 14:46:00 +01:00

Note, this is a summary of the discussion with @Sergey on IRC after it was requested that pillow be included with Blender. While I don't intend to work on this near term, I'm happy to help someone else take on this task - @ideasman42 .

(NOTE) Update: A very basic image API has been committed to master & 2.8 branch 409cfba1a3, this was done so we can more easily accept incremental improvements.

There are cases where it's useful to manipulate image data in Python, outside of Blender's image data-blocks (which are user data that's saved to file).

The Python module 'pillow' is a capable module, however we would prefer to expose Blender's internal image operations, instead of bundling pillow with Blender.

Reasons include:

100% compatibility with Blender's file formats, so all files that load in Blender load through Python (including details like compression methods, meta-data and particular color-management settings).
Bundling pillow adds more burden for platform maintainers, also increases download size.
Image support can be buggy (security CVE's, bugs in one image loader not in another).
Using Blender's image support means any improvements here will benefit Blender too.
Potential for better integration with the rest of Blender (so passing images from Python can be used in Blender as-is).

We could initially support a basic API:

- load/save (done)
- rotate
- scale
- crop
- simple color operations (brightness contrast)
- direct pixel access using Python buffers.

Once basic support is working well we might consider:

more advanced effects (perhaps de-duplicate with the sequencer effects/modifiers).
color management access & conversion.
text drawing (using the blf API, which already works in C, use for text in the sequencer).
blitting content between images.

... others cold be added, these are just suggestions.

Note that additions to this API would mean some refactoring & improvements to ImBuf since the Python API would be a thin wrapper on ImBuf operations.

*Note, this is a summary of the discussion with @Sergey on IRC after it was requested that pillow be included with Blender. While I don't intend to work on this near term, I'm happy to help someone else take on this task - @ideasman42 .* --- (NOTE) Update: A very basic image API has been committed to master & 2.8 branch 409cfba1a3, this was done so we can more easily accept incremental improvements. There are cases where it's useful to manipulate image data in Python, outside of Blender's image data-blocks (which are user data that's saved to file). The Python module ['pillow' ](https://python-pillow.org) is a capable module, however we would prefer to expose Blender's internal image operations, instead of bundling pillow with Blender. Reasons include: - 100% compatibility with Blender's file formats, so all files that load in Blender load through Python (including details like compression methods, meta-data and particular color-management settings). - Bundling pillow adds more burden for platform maintainers, also increases download size. - Image support can be buggy (security CVE's, bugs in one image loader not in another). - Using Blender's image support means any improvements here will benefit Blender too. - Potential for better integration with the rest of Blender *(so passing images from Python can be used in Blender as-is)*. We could initially support a basic API: - - [x] load/save (done) - - [ ] rotate - - [x] scale - - [x] crop - - [ ] simple color operations (brightness contrast) - - [ ] direct pixel access using Python buffers. Once basic support is working well we might consider: - more advanced effects (perhaps de-duplicate with the sequencer effects/modifiers). - color management access & conversion. - text drawing (using the `blf` API, which already works in C, use for text in the sequencer). - blitting content between images. ... others cold be added, these are just suggestions. Note that additions to this API would mean some refactoring & improvements to `ImBuf` since the Python API would be a thin wrapper on `ImBuf` operations.

Campbell Barton self-assigned this 2018-03-08 14:46:00 +01:00

Campbell Barton commented

2018-03-08 14:46:00 +01:00

Added subscribers: @Sergey, @ideasman42