Ad a own Generator and can handle with WebP and AVIF preview.

[JanisPlayer]

Title: Improved AI Input Image Generation with GD

Description:

This change enables the generation of custom input images for AI with better quality using GD for supported image formats. This results in improved recognition accuracy.

Configuration Options:

• To disable this feature, set 'recognize.preview.gd' to 'false' in the configuration.
• To set the quality of JPEG images generated, use 'recognize.preview.quality' (default is '100').

If the image format is not supported, the standard preview generator is used. Additionally, if the standard preview generator produces a WebP or AVIF image format that the AI cannot process, this image is converted to JPEG using GD.

Considering the known issues with WebP previews, I have created a patch to address these problems and enhance recognition quality:

• Pull Request for WebP (accepted from version 28): Imaginary WebP support server#38032
• Pull Request for AVIF (currently not accepted and work in progress): Add AVIF Thumbnail Generation server#40048

Please refer to the discussion that led to this Pull Request for more context and insights: #996

The code has been tested on my Nextcloud instance. While I acknowledge that this solution may not be perfect, I couldn't find a better one in a short time. Any suggestions for improvement are highly welcome.

[marcelklehr]

Hey! I'm sorry for the delay. This looks really good! Just approved CI so let's see what the tests say :)

[marcelklehr]

Awesome! I refactored it a little but seems to work like a charm. Thank you 💙

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