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.
The JPEG Club releases jpegtran, and for Windows users JpegCrop, which both allow various lossless operations on JPEG files such as:
- Rotation by 90, 180 & 270 degrees
- Flip Horizontal or Vertical
- Cropping you loose the removed information
- Create progressive jpeg
- Resize JPEG 9 only so a waning that some applications may not display the resulting image
But you example images require scaling the vertical element only - this is not possible without recompression so you would be better off with GIMP or ImageMagick - both of which are free, gratis & open source plus available for a number of platforms.