Can I use it without GUI? (I need to crop in the background?)

[martinenkoEduard]

Can I use it without GUI? (I need to crop in the background?)
Can you please share some simple examples.

I have a file image or state.previewURL= URL.createObjectURL(event.target.files[0]);
And I want to crop it by some coordinates, and get a blob or a new file?
Is it possible to set jpeg quality?

[fengyuanchen]

You can put the source image into an opacity container, e.g.:

<div style="opacity: 0; z-index: -1;">
 <img id="image" src="...">
</div>