I have an image and it's a jpg.
I tried running through jpegtran with the following command:
$ jpegtran -copy none -optimize image.jpg > out.jpg
The file outputs, but the image seems un-modified (no size change)
I tried jpegoptim:
$ jpegoptim image.jpg
image.jpg 4475x2984 24bit P JFIF [OK] 1679488 --> 1679488 bytes (0.00%), skipped.
I get the same results when I use --force with jpegoptim except it reports that it's optimized but there is no change in file size
Here is the image in question: https://i.sstatic.net/GVQ7x.jpg
But I can't seem to get it to work with any other jpegs I have either (only tried a couple though).
Am I doing something wrong?
I downloaded your image from imgur, but the size is 189,056 bytes. Is it possible that imgur did something to your image?
Anyway, I managed to optimize it to 165,920 bytes using Leanify (I'm the author) and it's lossless.