Does anyone know of a good way to split a pdf's pages down the middle into two new pages?
To be clear, I'm not trying to split out already existing pages from a pdf; I am trying to create two new pages from an existing single page.
It lets you split each page into as many subpages as you want by defining regions with a GUI. It groups all similar pages into groups for you, so you can define regions for that group once.
It's cross-platform, free, and open-source.
You can solve this with the help of Ghostscript.
How to solve this with the help of Ghostscript...
...and for the fun of it, I've recently done it not with an input file featuring "double-up" pages, but one with "treble-ups". You can read the answer for this case in this other response.
Your case is even simpler. You seem to have something similar to this:
You want to create 1 PDF with 4 pages, each of which has the size of 421 pt x 595 pt.
Let's first extract the left sections from each of the input pages:
What did these parameters do?
First, know that in PDF 1 inch == 72 points. Then the rest is:
Which result did the last command achieve?
Next, the right sections:
Now we combine the pages into one file. We could do that with ghostscript as well, but we'll use
Done. Here is the desired result. 4 different pages, sized 421x595 pt.
To expand upon @Kurt's answer (since I don't have enough reputation points to comment) first make sure the dimensions you use is not based on the Crop Box dimensions if they are different from the Media Box dimensions. The output size is based on Media Box dimensions, but the offset seems to use the Crop Box dimensions.
For a gatefold page that had a 20.0833 x 13.833 media box and a 19.25 x 13.0 crop box which was the same as the trim box in my document, to split it into two pages on Ubuntu, for the left side:
The right side:
And then stitched them with
An alternative would be to set the crop box to the same as the media box; then the offset would be -723. But then the crop would have to be reset to trim in order for the pages to appear seamless. Otherwise, set media to crop.
If you are comfortable with some programming or prepared to give it a go, then you could:
Using the iText library you can to manipulate PDFs.