Thanks useful information: 
An interesting discovery about the lens on my little Canon G9X II - and probably about many other broadly similar cameras.
We all know (at least we all should know) that lens designers have to make all sorts of compromises, and the one I'm interested in here is the three way-compromise between (a) simplicity and ease of manufacture, (b) sharpness, and (c) correction to achieve a rectilinear picture at wider angles. In a sense, lenses don't "want" to be rectilinear, they "want" to be fisheyes and the lens designer has to add elements to correct for that. These modifications come at a price: extra elements cost more, weigh more, and every extra surface reduces clarity by a little bit.
Now the Canon G9X II is regarded as having an excellent zoom lens, equivalent to a 28-84mm full frame and very fast at f/2.0-4.9. Brilliant lens design, yes?
Well, it turns out that there is a trick to it.
First, here is a JPG straight out of the camera.
(Huon River at Judbury. In-camera JPG.)
Now here is what you get from the raw, using Canon DPP with the default settings.
(Huon River at Judbury. Canon DPP, default settings.)
As you can see, that is virtually identical to the in-camera JPG - as it should be seeing as Canon makes a point of using the exact same logic on both tasks.
Now let's move on to DxO Photo Lab, again using default settings.
(Huon River at Judbury. From the raw, DxO default settings.)
DxO make a point of physically testing as many cameras and lenses as they can get their hands on and correcting optical flaws more accurately than any other company. Sometimes this means having to crop the result more, as can be seen.
But now we get to the interesting bit. Here is what you get using DxO with the lens distortion corrections switched off. This is what the sensor on the camera actually sees.
(Huon River at Judbury. From the raw, DxO with lens corrections disabled.)
What is going on here is that Canon's designers have said "We can make a sharper, smaller, cheaper lens by leaving out the corrective elements, and no-one will notice the lack because our in-camera development software will de-fish the JPGs, and our raw software will do the same". Third-party companies like DxO and Adobe know to do it too. It is only when you turn the software smarts off that you see what the lens actually does.
(Probably you lot have known all this for years - the G9X II is quite old now. But it is news to me.)
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