Thanks for your post.
I am afraid that batch image editing is not possible using the Editor. We do provide some basic filters that you may apply to each image before creating the PDF file, but that is all we offer in terms of image editing.
If you would like to edit your images before creating a PDF document, please try using a third party image processing software that would have a lot more options than ours. Once you apply the changes, you can create your PDF file using the Editor with ease.