Is your feature request related to a problem? Please describe.

It would be interesting to play with progressive decoding by adding a slider to control the percentage, or absolute number of kB of an encoded file to send to the decoder. The user could see how much of the image could be rendered with a partial file.

Describe the solution you'd like

A slider at the bottom of the viewer controls how much data is sent to the image decoder. The decoder is instructed to return what image data it can even if the stream is incomplete.