[Feature Request]: Allow tags to apply preset filters/modifications to the thumbnails of entries

[TrigamDev]

Checklist

• I am using an up-to-date version.
• I have read the documentation.
• I have searched existing issues.

Description

Some users may want to have certain entries to have a blurred/hidden thumbnail by default, being shown only when the entry is opened. This can also expand to other filters, modifications, effects, etc, though personally I only need blurring/hiding.

Solution

When configuring a tag, a new option could be added for choosing multiple filters/modifications to be applied to the entry's thumbnail. For example, if the user creates a "Blur" tag, all entries tagged with it will have blurred thumbnails.
A handful of preset filters could be included, such as blurring, hue shifting, grayscale, etc. This could also include other useful things that the user may want control over, such as interpolation algorithm (nearest neighbor, bilinear, etc).

Some potential expansions of the feature, though not part of the request itself, could be:

• A separate filter could be chosen that applies to the entry itself
• Support for user-created filters

Alternatives

The user could modify the thumbnail file in the .TagStudio/thumbs directory directly, but

1. Requiring needing to modify anything in the .TagStudio directory is obviously undesirable
2. When the file is modified, a new thumbnail is generated, requiring the user to modify the thumbnail again

[CyanVoxel]

I can see the blur filter definitely being useful, and I like the idea of something like that being tag-based. It's somewhat similar to the planned feature of having a "Hidden" property checkbox on tags that allow tagged file entries to be hidden from searches by default - which is also the intended final behavior of the built-in "Archived" tag. I was originally going to suggest connecting them to remove the need for a new property, however I realized that there may be several situations where having an archived file may be different from ones you wish to have blurred.

hue shifting, grayscale; Support for user-created filters

These have a bit less utility than blurring in my opinion. It would also increase the complexity compared to a "blurred/not blurred" property.

This could also include other useful things that the user may want control over, such as interpolation algorithm (nearest neighbor, bilinear, etc).

Currently, TagStudio uses bilinear filtering for images whose resolution is larger than the displayed dimensions, and nearest neighbor for images with a smaller resolution than the final dimensions. This results in anti-aliased previews for large images while keeping clean sharp previews for low-resolution images such as pixel art. So far I haven't noticed a case where it would really be desirable to manually switch between them per file entry - is there any specific examples you were thinking of?

[TrigamDev]

These have a bit less utility than blurring in my opinion. It would also increase the complexity compared to a "blurred/not blurred" property.

Yeah that's true. Personally, all I need is blurring, and that's definitely the most useful one (though, I could also see myself using grayscale as well). I just felt that generalizing it to a list of filters, rather than a "blur" property both gives more customization and opens up for there to be more filters added in the future if needed.

So far I haven't noticed a case where it would really be desirable to manually switch between them per file entry - is there any specific examples you were thinking of?

Some pixel art can have a fairly high resolution, which may be enough to put it over the threshold for bilinear filtering. Though, in any case, I believe letting the user have control over how the image is interpolated is good.