Batch Processing allows you to post-process several images at once, or a whole folder, with a few simple clicks and moves. Batch processing is quite useful for creating animations from a set of post-processed pictures. 
First, load an image that will serve as a template object and apply a style of your choice. This style will be applied to all the images you will select to batch-process. Switch to the Batch Processing view.

Choose whether to batch process a whole folder or only a few files. If you want to batch process a few files, check Selected Files on the left hand. Choose the images by double-clicking them.

In this tutorial we will chose Folders. Define the Source path of your images and the Target folder’s path, and assign an Output suffix if you wish, but you can also leave it blank. This suffix can be any word or number you want, such as draft, final, -1, etc. This suffix will be added to all the batch-processed image names with an underscore. Define the Template Object and the Output file format, then click Start. 
If you are working with only one Object, it will be selected as the Template Object by default. Using multiple objects can be useful when you have a background, foreground or texture to add to all the processed images. In this case, the selected Template Object will be replaced by the processed files, but the other objects (like a canvas texture) will remain the same in all processing steps.

PostworkShop will start processing all the images contained in the folder. A double progress bar will show the processing of the current file (above) and the progress of the whole batch (below). The Processing Log shows the processed file's path and the created file's path.

When the processing is finished, you will see the whole list of files edited. You can now switch back to the Compositing viewport. 

Go to your folder to see all the result images. In the image above see the two folders: DemoImages - the images before processing, and below the ResultImages folder with the images postworked. Even if your folder contains images of different shapes and sizes, PostworkShop will obviously keep your images size and shape.