I was in need of this recently, and found that an ImageMagick one-liner can do the job quite nicely: https://gist.github.com/andyrbell/25c8632e15d17c83a54602f6a

I was in need of this recently, and found that an ImageMagick one-liner can do the job quite nicely: https://gist.github.com/andyrbell/25c8632e15d17c83a54602f6acde2724 https://gist.github.com/andyrbell/25c8632e15d17c83a54602f6ac...