Is there a way to script image creation? I am facing a though challange - I need to perform repetitive Image formating. Firstly, I need resize picture A so that it has some fixed width in pixels. Then, I need to place picture A in the middle of picture B. I need to perform this task repetitively for hundreds of images. Is there any way to script this, so that I can just type in for example:

perform pictureA.png pictureB.png output.png


Any help is more than welcome!
ImageMagick is a set of command-line tools that can do the sort of things you describe. For example, this command line will overlay picture B with a centered copy of picture A, resized to 100 pixels wide (keeping aspect ratio):

convert pictureB.png ( pictureA.png -resize 100 ) -gravity center -composite output.png


See the ImageMagick docs for more info about its command lines are structured...it's a powerful piece of software, but it takes a bit of work to get the hang of how to use it.