My guess is that it would be much more expensive unless it's a frequently accessed image. CPU and GPU time is much more expensive than storage costs on any cloud provider.
Wouldn't it be cheaper if the image is infrequently accessed? I'm thinking in the extreme case where you have some 10-year-old photo that no one's looked at in 7 years. In that case the storage costs are everything because the marginal CPU cost is 0.
It depends if the decompression is done on the server or on the client. If the client is doing the decompressing it would be better to compress frequently accessed images because it would lower bandwidth costs. If the server does the decompressing it would be better for infrequently accessed images to save on CPU costs.
Where it might be very useful is for companies who distribute Cellular IOT devices where they pay for each byte uploaded. That could have a real impact on cost with the tradeoff being more work on-device (which can be optimized).
