Simple web-based image editor

The idea is a simple HTML image editor that supports cropping. The user would arrive on a page where an editor component would show a single image. The image should be sized such that it's entirely visible in the viewport. The user could then adjust the bounds of the image and click the submit/done button which would POST the edited image data to an endpoint and navigate to a new page containing the edited image. See "Editor [login to view URL]" attached. An HTML canvas seems like a good fit here. All the processing should be done client side and the POST should contain the edited image contents. The canvas API seems to support this. - Editor component should easily integrate into another webpage. E.g. it shouldn't interfere with a header or footer in an existing page. - Should support modern Chrome, Firefox, IE, Edge & Safari on desktop and mobile. I don't care about ancient browsers. - Vanilla browser JS to minimize dependencies. Definitely no Flash. No React or Angular. Probably no jQuery or [login to view URL] unless there's a really good reason. - If any image assets are required, I will provide them, although I don't much will be required here. - Even though the image should be scaled to fit in the viewport, the image sent in the POST should be the same scale as the original image. - The tool must work well on mobile. It must be possible to adjust the crop dimensions easily (think iPhone gallery built in editor easy, see attached "iPhone [login to view URL]"). If this v1 works out well, I would be interested in growing editing functionality to include things like drawing arrows and other markup, or rotate and zoom. That would be a later job, however.