APL editing - using Acrobat Pro to crop and rotate

Sytske and I are planning a series of short notes on ways to approach editing the scans for Antique Pattern Library. There are many ways to do it, and we each prefer different software and workflows. Some things are true for all of the books.
So here goes. OK, not so short today...

Right now I'm working on The Young Ladies Journal Complete Guide to the Work-Table, Containing Instructions in Berlin Work, Crochet, Drawn-Thread Work, Embroidery, Knitting, Knotting or Macrame, Lace, Netting, Poona Painting & Tatting, with Numerous Illustrations and Coloured Designs. The title says it all.  It was published in London, 1884, so will eventually end up on our British Victorian page, and is a wonderful resource book for needleworkers and fans of the Victorian era.

I'm often in IM with Sytske while we do this, so I can ask questions. This is her book, she scanned it a few years ago, and remembers it vividly.

The background: We often scan small books or booklets by flattening them open on a scanner so that we take two pages in each image. As we edit we crop each page so that a single page will exhibit on the pdf file at a time - easier to read, especially on mobile devices, and a craft worker often needs to print only one page to work from.

The question: Is it better to crop the pages first, then edit them, or edit the two-page image, then edit? We've both tried it both ways, with different software.
The answer: Crop first, then edit.
The why:

• Fixing crooked image rotations can be done automatically (I usually do it in Acrobat Pro), but not if two pages are pointing in different directions on the same image.
• Automating such things as Replace Color to remove smutch from backgrounds is often different from page to page, even on the same scan.
• A colored page facing a b&w page needs to be saved differently: Index color for color, grayscale for b&w. 

The how: I now use Acrobat Pro to separate the pages, though I've also used PhotoShop and other image editing software. I make sure the images are named so they sort in book number order, load them into Acrobat Pro twice, then fiddle with the sort order there to make sure they'll save to a pdf file in the right order. After I create this rough pdf file, I crop all of the left side, odd numbered pages, then the right side, even numbered pages, working cautiously in small batches, and save the file. Then I run Text Recognition, carefully (don't use clear scan), to keep the image intact at the same or better dpi. , to automatically clean up most rotation issues. Save again, then save the pdf file to Image>PNG to a folder called "editing", which gives me single pages, cropped, rotated, and ready to edit.
Sytske does it differently, and she may post with her tips sometime soon. :)

Judith Adele (Ada Radius in virtual worlds)