Add an option to display a reference image behind the SVG

[KittyMcTophat]

Limitation
I want to recreate a png image in svg format, but I want to trace over the original to get it right. Currently, I can't do that since it's not a feature.

How It Will Help
By adding the option for displaying a reference image, it will become much easier to recreate images in svg format, because they can be traced.

Implementation Details
My proposal is to add an option to load a reference image, which would be rendered behind the svg image at 50% transparency or something like that, allowing a much easier way to recreate raster images in svg format.

It would also be helpful if there were a button or a hotkey to toggle the visibility of the reference image, since that'd make it easy to quickly tell which parts of the image aren't done yet at a glance.

[MewPurPur]

I approve of the idea! But still haven't quite fleshed out the implementation details. I think this should be behind a new button on the top, which could also include other handles like the background pattern and an opacity for the image.

I'm not sure how to handle aspect ratios.

[Kiisu-Master]

Should also add option for plain color
I had this idea a while ago but never talked about it 🙃

[MewPurPur]

Some ideas for implementation details would help me a lot to approach this.

[vthilag]

Some ideas for implementation details would help me a lot to approach this.

Funnily enough, I wanted to vectorize a rasterized logo in godsvg and found this.
My idea would be a menu near the settings icon on top of the visual editor which has a sub menu called image reference that has the following options:

1. Select Image
2. Is Visible
3. Overlay Image or Display behind
4. Opacity
5. Lock transform
6. Edit: Maybe some transform inputs here as well and a toggle to lock aspect ratios when scaling.
   (Some of these can and probably should be separate items outside the menu for quick access)

When not locked you'd be able to click and transform the reference image and when it locks it'll no longer be selectable.

That's how I'd probably use it but they're definitely better ways.
Also edit: With how clunky this could be as a menu item, maybe it can be a floating window in the visual editor thats there as long as the reference image button is toggled on

[MewPurPur]

Thanks! This will help me (or others) get started.

[Qainguin]

This should be implemented now by #728.

[MewPurPur]

Yeah. More advanced requirements can be discussed separately and implemented when the need for them becomes a priority.