Got this jpeg image that has incorrect proportions. That's how it should look but here's the thing - by simple means of resizing and recompressing it to jpeg, after conversion the size gets bigger and the quality of course gets worse. So I'm curious if it's possible to simply change its aspect ratio via some header information and avoid conversion.
I don't think the incorrect proportion one is much better from the resided one. but if you want to not making re-size and get the picture wore here is a tip.
the bad one is a square of (1400xp*1400px) the bigger one is (2359xp*1400px) that's mean you stretched the X approximately 168.5% times ... stretching an image may cause lose of resolution.
the bigger one having an aspect ration of 1.6 -- I mean the X of the image is bigger of its Y about 1.6
Instead of stretching X I recommend downsize Y keeping the X at the same resolution and condensed the y only, to avoid "pixilation" when stretching.
What I mean is why don't you re-size the squared deformed image to be 1400px*830PX ?? having the same aspect ratio and in that case you will never lose the resolution.
If it's used on a webpage, you can specify a width and height to have the browser resize it without redownloading:
<img src="http://i.imgur.com/weLH3Mb.jpg" style="width: 2359px; height: 1400px">
But it's entirely possible to get that JPEG smaller without a noticeable loss in quality. While it's true that JPEG files lose quality with every recompression, it's usually not very noticeable.
See this resized and recompressed version, for example, at 200 kB vs the original's 365 kB:
I just resized it and turned the JPEG quality lower when I saved.