In addition to get the QR code from a file, it would be nice if Qrca could use image from the clipboard.
I was just about to create a similar request. I've got 2 more suggestions: 1. Read image from clipboard (by either using Ctrl+V or by a "paste from clipboard" added to the 3 dot menu). 2. Open image from a command line argument, so you can export image from Spectacle directly to Qrca. 3. Add a possibility to read the already open image again. Currently you need to browse for the image again if the results message is closed. Or do not close the message automatically after clicking on the action (e.g. open totp link).